- Email: [email protected]

Review

Tunable laser optics: Applications to optics and quantum optics F.J. Duartea,b,n a Interferometric Optics, Rochester, New York, USA University of New Mexico, Albuquerque, New Mexico, USA

b

Available online 9 October 2013

Abstract Optics originally developed for tunable organic dye lasers have found applications in other areas of optics, laser optics, and quantum optics. Here, the salient aspects of the physics related to the cavity linewidth equation and the effects of intracavity beam expansion and intracavity dispersion on this equation are reviewed. Additionally, the generalized multiple-prism dispersion equation is applied to direct-vision prisms, also known as Amici prisms, to calculate dispersion conﬁgurations of practical interest. Then, the higher derivatives of the multiple-prism dispersion equation applicable to laser pulse compression are considered. From this perspective, a new compact and generalized equation for higher-order phase derivatives is introduced for the ﬁrst time. Furthermore, it is shown how the N-slit interferometric equation, derived from quantum principles using Dirac's notation, gives rise to generalized versions of the diffraction grating equation and the law of refraction. The nexus between the N-slit interferometric equation and the cavity linewidth equation is also illustrated. Finally, various optical and quantum optical applications that have beneﬁted from these developments are highlighted. & 2013 Elsevier Ltd. All rights reserved. Keywords: Amici prisms; Generalized multiple-prism dispersion; Prismatic pulse compression; N-slit interferometric equation; Organic lasers; Quantum entanglement

Contents 1. 2. 3.

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Laser wavelength tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Expanded beam illumination of diffraction gratings in Littrow conﬁguration . . . . . . . . . . . . . 327

n

Correspondence address: Interferometric Optics, Rochester, New York, USA. E-mail address: [email protected]

0079-6727/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.pquantelec.2013.09.001

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

327

4.

Feedback from gratings in grazing-incidence conﬁguration . . . . . . . . . . . . . . . . . . . . . . . . . 329 4.1. Applications to tunable diode lasers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 5. Multiple-prism beam expansion and generalized multiple-prism dispersion equations . . . . . . . 330 5.1. Direct-vision, compound, and Amici prisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 5.2. Applications to tunable lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 6. Generalized higher-order multiple-prism dispersion equations for laser pulse compression . . . . 338 6.1. Applications to laser pulse compression and coherent microscopy . . . . . . . . . . . . . . . 340 7. The quantum interferometric connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 7.1. Interference and quantum entanglement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 8. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345

1. Introduction Soon after the discovery of the organic dye laser in 1966 by Sorokin and Lankard [1] and Schäfer et al. [2], the tunability of this laser source inspired several developments in optics that have found widespread applications in the ﬁeld of lasers and in optics in general. The development of these techniques and their link to major subsequent developments in physics and science is reviewed here. Although the text only refers to the interaction of these contributions with speciﬁc optics and laser developments, it should be kept in mind that the narrow-linewidth tunable lasers and the ultrashort pulse lasers that adopted the dispersive techniques described here have had major impacts in a plethora of important ﬁelds including astronomy [3,4], laser isotope separation [4–6], medicine [7,8], photochemistry [9], spectroscopy [10,11], and ultrashort pulse phenomena [12]. This paper is dedicated to the memory of F.P. Schäfer (1931–2011), one of the discoverers of the organic dye laser, who displayed a keen interest in the dispersive optical techniques applied to tunable organic dye lasers [13]. 2. Laser wavelength tuning The ﬁrst broadband laser wavelength tuning was performed by Soffer and McFarland [14] in 1967. They used a grating in the Littrow conﬁguration to demonstrate the tuning of a Rhodamine 6G laser. The tuning range was approximately 555 r λr 590 nm with a reported linewidth of Δλ 4 nm. For a cavity tuned with a grating in the Littrow conﬁguration the emission wavelength is given by mλ ¼ 2d sin Θ

ð2:1Þ

where λ is the laser emission wavelength, m is the order of diffraction, and d is the groove density of the diffraction grating in lines/mm. This equation is a special case of the more general diffraction grating equation discussed later. Fig. 1 describes a telescopic tunable dye laser cavity incorporating a Littrow grating as the tuning element. 3. Expanded beam illumination of diffraction gratings in Littrow conﬁguration Following the introduction of the dye laser [1,2] and the demonstration of its tunability by Soffer and McFarland [14], a powerful class of tunable laser sources in the visible was made available to the scientiﬁc community. This momentous discovery occurred in 1972 when Hänsch

328

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

Fig. 1. Littrow cavity conﬁguration incorporating two-dimensional intracavity telescopic beam expansion.

[15] realized that expansion of the intracavity beam illuminating the tuning diffraction grating yielded an enormous reduction in the laser emission linewidth. Hänsch utilized a two-dimensional astronomical telescope comprised of two convex lenses (see Fig. 1). What Hänsch discovered can be succinctly explained by the cavity linewidth equation for a single-pass laser 1 ∂Θ Δλ Δθ ð3:1Þ ∂λ where the beam divergence Δθ can be represented by the diffraction-limited relation Δθ

λ πw

ð3:2Þ

Here, λ is the laser emission wavelength, and w is the beam waist at the gain region. As explained later, in Section 5, the reduction in the emission linewidth is a consequence of the large increase in intracavity dispersion, this increase results from the illumination of the diffraction grating by the expanded beam. However, Hänsch interpreted the effect in an equivalent mathematical form corresponding to a reduction in the intracavity beam divergence [15] Δθ

λ πMw

ð3:3Þ

Because the magniﬁcation factor M can be rather large, the subsequent reduction in the laser linewidth can be rather dramatic. In fact, Hänsch was able to measure linewidths of Δν 2:5 GHz at λ 600 nm, or Δλ 0:003 nm. Further reductions were achieved through the introduction of an intracavity etalon [15]. In Eq. (3.1), the angular dispersion of the grating, deployed in Littrow conﬁguration is given by [15] ∂Θ 2 tan Θ ð3:4Þ ¼ ∂λ λ where Θ is the angle of incidence, which equals the angle of diffraction for the Littrow-mounted grating. In addition to the technical accomplishment of high-power tunable narrow-linewidth emission, the signiﬁcance of Hänsch's contribution was the realization that intracavity beam expansion, or

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

329

illumination of the whole diffraction grating, led to a gigantic reduction in the laser emission linewidth. At this stage, it should be mentioned that both the expressions applied by Hänsch, the expression for the single-pass linewidth (Eq. (3.1)) and the diffraction-limited beam divergence (Eq. (3.2)), can be found in classical optics books. For instance, Eq. (3.1) can be referenced to Robertson in 1955 [16], and Eq. (3.2) can be traced to Jenkins and White in 1957 [17]. However, as will be shown later, these expressions can also be derived from the principles of quantum optics. 4. Feedback from gratings in grazing-incidence conﬁguration The next important development in the optics of tunable lasers was the introduction of grazing-incidence grating conﬁgurations by Shoshan et al. [18] and Littman and Metcalf [19]. The physics of linewidth narrowing remains essentially the same as the narrowing considered by Hänsch except that instead of using an expanded beam to illuminate the entire diffractive surface of the grating, these authors utilized the divergent emission to illuminate a diffraction grating deployed at a grazing-incidence angle, as illustrated in Fig. 2 for an open cavity conﬁguration and in Fig. 3 for a closed cavity conﬁguration. Thus, the linewidth equation becomes 1 ∂Θ Δλ Δθ ð4:1Þ ∂λ GI where Δθ is the beam divergence given by Eq. (3.2), and the angular dispersion for the diffraction grating in the grazing-incidence conﬁguration is given by ∂Θ ð sin Θ þ sin Θ′Þ ð4:2Þ ¼ ∂λ GI λ cos Θ or

∂Θ m ¼ ∂λ GI d cos Θ

Fig. 2. Grazing-incidence grating oscillator in an open cavity conﬁguration.

ð4:3Þ

330

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

Fig. 3. Grazing-incidence grating oscillator in a closed cavity conﬁguration.

where λ is the laser emission wavelength, m is the order of diffraction, and d is the groove density of the diffraction grating in lines/mm. Certainly, these dispersion expressions are derived from the diffraction grating equation [19] mλ ¼ dð sin Θ7 sin Θ′Þ

ð4:4Þ

Again, some observations are in order. First, the dispersion equations applied here to grazingincidence grating cavities are often multiplied by a factor of 2 to indicate a double-pass conﬁguration [18]. Additionally, as for beam divergence, the diffraction grating equation is adopted from classical literature. In this case, we can trace Eq. (4.4) all the way back to Michelson's 1927 book entitled Studies in Optics [20]. It will also be shown later that this expression can also be derived from quantum optics principles. 4.1. Applications to tunable diode lasers Grazing-incidence grating conﬁgurations, developed for the organic dye laser [18,19], have been extensively applied to other types of lasers, including gas lasers [21,22] and solid-state tunable lasers [23,24]. However, these conﬁgurations have had their greatest inﬂuence through their widespread application to tunable semiconductor lasers, in which straightforward open cavity designs have had a major impact on the development of the tunable diode lasers used in laser cooling experiments [25,26]. 5. Multiple-prism beam expansion and generalized multiple-prism dispersion equations Prismatic beam expansion and multiple-prism arrays were ﬁrst disclosed by Newton in his timeless book Opticks [27], in 1704 (see Figs. 4 and 5). Although these ideas would be used sporadically following their introduction [28], it was the tunable organic dye laser that revived their use some 270 years later. Of particular interest here was the use of a single-prism beam expander by Hanna et al. [29] and a study on double-prism expanders by Kasuya et al. [30]. The success of intracavity multiple-prism beam expansion conﬁgurations [31,32], depicted here in tunable organic solid-state dye laser oscillators [33,34] in Figs. 6 and 7, inspired Duarte and Piper to introduce the generalized multiple-prism dispersion theory [35]. For generalized

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

331

Fig. 4. Newton's single-prism diagram depicting expansion of a light beam from Newton's 1704 book Opticks [27].

Fig. 5. Newton's prism array from Newton's 1704 book Opticks [27].

multiple prism arrays of any geometry and material, see Fig. 8, the dispersion can be succinctly expressed as [35] ∇λ ϕ2;m ¼ H2;m ∇λ nm þ ðk 1;m k 2;m Þ 1 ðH1;m ∇λ nm 7∇λ ϕ2;ðm 1Þ Þ

ð5:1Þ

where ∇λ ¼

∂ ∂λ

ð5:2Þ

k1;m ¼

cos ψ 1;m cos ϕ1;m

ð5:3Þ

k2;m ¼

cos ϕ2;m cos ψ 2;m

ð5:4Þ

H1;m ¼

tan ϕ1;m nm

ð5:5Þ

H2;m ¼

tan ϕ2;m nm

ð5:6Þ

In these equations, for the mth prism, nm is the refractive index, ϕ1;m is the incidence angle, and

332

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

Fig. 6. Hybrid multiple-prism pre-expanded near grazing-incidence (HMPGI) grating solid state dye laser oscillator, from Duarte [33].

Fig. 7. Multiple-prism Littrow (MPL) grating solid-state dye laser oscillator, from Duarte [34].

ψ 1;m is the corresponding refraction angle. Similarly, ϕ2;m is the emergence angle, and ψ 2;m is the corresponding refraction angle. Additionally, k1;m and k 2;m are the beam expansions at the incidence and the exit surfaces, respectively. Furthermore, H1;m and H2;m are geometrical identities related to ϕ1;m and ϕ2;m , respectively. Physically, the generalized single-pass multiple-prism dispersion equation tells us that the cumulative dispersion, at the mth prism (∇λ ϕ2;m ), depends on the geometry of this particular prism, the angle of incidence at this prism, the material of this prism, and the cumulative dispersion up to the previous prism, ∇λ ϕ2;ðm 1Þ [35,36]. The dispersion expression given in Eq. (5.1) applies to a single pass and is technically known as the single-pass generalized multiple-prism dispersion equation. To describe the physics of linewidth narrowing in a pulsed high-gain tunable laser oscillator, it is necessary to consider the double-pass multiple-prism dispersion. The double pass is constructed by unfolding the single pass through the multiple-prism grating, or multiple-prism mirror, assembly used to induce linewidth narrowing in the frequency-selective laser cavity as illustrated in Fig. 9. Thus, as

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

333

Fig. 8. (a) Generalized multiple-prism array in a positive conﬁguration, and (b) in a compensating conﬁguration. Generalized prismatic conﬁgurations of this class were ﬁrst introduced by Duarte and Piper [36].

explained by Duarte and Piper [35] the double-pass angular multiple-prism dispersion becomes ∇λ ϕ01;m ¼ H01;m ∇λ nm þ ðk 1;m0 k2;m0 Þ 1 ðH02;m ∇λ nm 7∇λ ϕ01;ðmþ1Þ Þ

ð5:7Þ

where k′1;m ¼

cos ψ′1;m cos ϕ′1;m

ð5:8Þ

k′2;m ¼

cos ϕ′2;m cos ψ′2;m

ð5:9Þ

H′1;m ¼

tan ′ϕ1;m nm

ð5:10Þ

H2;m0 ¼

tan ϕ2;m0 nm

ð5:11Þ

An important term in Eq. (5.7) is ∇λ ϕ′1;ðmþ1Þ , which links the angular dispersion of the doublepass, or single return-pass, to the last stage of the single-pass angular dispersion and includes the diffraction grating dispersion so that [37] ∇λ ϕ′1;ðmþ1Þ ¼ ð∇λ Θ7∇λ ϕ2;r Þ

ð5:12Þ

334

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

Fig. 9. Unfolded multiple-prism grating conﬁguration utilized to derive the double-pass, or single return-pass, multipleprism dispersion, adapted from Duarte and Piper [35].

If the diffraction grating is replaced by a mirror, ∇λ Θ ¼ 0, this equation leads directly to ∇λ ϕ′1;ðmþ1Þ ¼ ∇λ ϕ2;r

ð5:13Þ

In these equations, ∇λ ϕ2;r is the overall cumulative single-pass angular dispersion calculated from Eq. (5.1) at the last prism of a prism array composed of r prisms. More speciﬁcally, for an array of r prisms, at the last prism ∇λ ϕ2;r ¼ ∇λ ϕ2;m

ð5:14Þ

Subsequently, Duarte and Piper [37] showed that the multiple return-pass cavity linewidth equation becomes Δλ ΔθR ðMR∇λ Θ þ R∇λ ϕ′1;m Þ 1

ð5:15Þ

where ΔθR is the multi-pass beam divergence, which approaches the diffraction limit in a welldesigned cavity [38], Ris a ﬁnite number of intracavity return passes [37], and M is the overall intracavity beam expansion deﬁned by [38,39] r

M 1 ¼ ∏ k1;m

ð5:16Þ

m¼1 r

M 2 ¼ ∏ k2;m

ð5:17Þ

m¼1

r

M ¼ M 1 M 2 ¼ ∏ k 1;m k2;m m¼1

ð5:18Þ

Here, we should indicate that in well-designed multiple-prism beam expanders with orthogonal beam exit angles, all the expansion is provided by M 1 , because M 2 1. Additionally, as highlighted recently [40], the relationship between single-pass and return-pass angular multiple-prism angular dispersion can

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

335

be expressed explicitly as ∇λ ϕ2;m ¼ ð2MÞ 1 ð∇λ ϕ′1;m Þ

ð5:19Þ

Thus, the return-pass cavity linewidth equation, which is Eq. (5.15), can also be expressed as Δλ ΔθR ðMR∇λ Θ þ 2MR∇λ ϕ2;r Þ 1

ð5:20Þ

After removal of the MR factor out, Eq. (5.20) can also be written as ΔθR ð∇λ Θ þ 2∇λ ϕ2;r Þ 1 ð5:21Þ MR For R ¼ 1 and for a dispersionless telescopic beam expander, that is, for ∇λ ϕ2;r ¼ 0, Eq. (5.21) reduces to Δλ

Δθ ð∇λ ΘÞ 1 ð5:22Þ M and this result is consistent with the equations utilized by Hänsch. The primary difference is that the beam-expansion factor M is now systematically and consistently introduced through the dispersion theory and augments the intracavity dispersion rather than being introduced in an ad-hoc manner as a factor that reduces the beam divergence as for the original telescopic design [15]. Δλ

5.1. Direct-vision, compound, and Amici prisms Some applications require direct-vision prisms [17] in which the beam of light does not deviate after refraction by a single prism. These prisms are essentially multiple-prism conﬁgurations in which the prisms are deployed right next to each other. These multiple-prism conﬁgurations are known as direct-vision prisms [17], compound prisms, or Amici prisms. These prisms are important in corrections of atmospheric dispersion in adaptive optics systems for astronomical applications [41]. Here, the single-pass generalized multiple-prism dispersion equation, Eq. (5.1), is applied to illustrate the dispersive properties of these prismatic conﬁgurations. The discussion begins by introducing a fused silica prism (n1 ¼ 1:45838 at λ ¼ 590 nm) with the following angular dimensions α1 ¼ 451, ϕ1;1 ¼ 20:661, ψ 1;1 ¼ 14:001, ψ 2;1 ¼ 31:001, ϕ2;1 ¼ 48:681, which are

Fig. 10. Single fused silica prism with a negative dispersion of ð∂ϕ2;1 =∂λÞ 0:0384 at λ ¼ 590 nm. Drawing is approximately to scale.

336

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

illustrated approximately to scale in Fig. 10. From Eq. (5.1), for m ¼ 1 and ðdn1 =dλÞ 0:0348 μm 1, the dispersion is ∂ϕ2;1 dn1 1:1036 0:0384 ð5:23Þ ∂λ dλ in units of μm 1. To prevent deviation in the beam path, a second prism is introduced in compensating conﬁguration and is adjoined to the ﬁrst prism to create a compound prism, or Amici prism, as illustrated in Fig. 11. The second prism is made of a higher refractive index material, in this case Schott SF10 (n2 ¼ 1:73020 at λ ¼ 590 nm) with an apex angle α2 ¼ 25:731. Here, it is noted that ϕ2;1 ¼ ϕ1;2 ¼ 48:681, ψ 1;2 ¼ 25:731, and ψ 2;2 ¼ ϕ2;2 ¼ 0. From Eq. (5.1), with m ¼ 2 and ðdn2 =dλÞ 0:1367 μm 1, the combined dispersion becomes ∂ϕ2;2 dn2 dn1 0:4818 0:8089 0:0377 ð5:24Þ ∂λ dλ dλ

Fig. 11. Amici prism conﬁguration with two prisms in compensating conﬁguration. The ﬁrst prism is made of fused silica and the second prism is made of the higher refractive index material Schott SF10 (see text). This conﬁguration yields negative dispersion of ð∂ϕ2;2 =∂λÞ 0:0377 at λ ¼ 590 nm. Drawing is approximately to scale.

Fig. 12. Amici prism, or direct-vision, conﬁguration with three prisms in compensating conﬁguration. The ﬁrst and last prisms are identical and are made of fused silica whereas the center prism is made of the higher refractive index material Schott SF10 (see text). This conﬁguration yields positive dispersion of ð∂ϕ2;3 =∂λÞ þ 0:0821 at λ ¼ 590 nm. Drawing is approximately to scale.

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

337

in units of μm 1. Although the propagation of the beam is now straight, the exit beam is slightly displaced relative to its position at the incidence surface. To achieve collinear transmission, the compound prism in Fig. 11 is unfolded to create a three-prism direct-vision conﬁguration [17], or a three-prism Amici conﬁguration, as illustrated in Fig. 12. For this particular conﬁguration: α1 ¼ 451, ϕ1;1 ¼ 20:661, ψ 1;1 ¼ 14:001, ψ 2;1 ¼ 31:001, α2 ¼ 51:461, ψ 1;2 ¼ ψ 2;2 ¼ 25:731, α3 ¼ 451, ψ 1;3 ¼ 31:001, ψ 2;3 ¼ 14:001, and ϕ2;3 ¼ 20:661. For Eq. (5.1) and m ¼ 3, the estimated combined dispersion is ∂ϕ2;3 dn1 dn2 1:7631 1:0503 þ 0:0821 ð5:25Þ ∂λ dλ dλ The change in the sign of the dispersion from Eq. (5.23), applicable to the single prism, to Eq. (5.25), applicable to the three-prism compensating conﬁguration, illustrates that the usual dispersion wavelength order (from red to blue), is inverted (from blue to red) and is consistent with the qualitative description given by Jenkins and White [17]. Thus, the single-pass generalized multiple-prism dispersion equation has been shown to be naturally applicable to the dispersion of direct-vision and Amici prismatic conﬁgurations. Furthermore, it also been shown quantitatively that although these compound prisms do provide an exit beam collinear with the incident beam, these compound prisms are also quite dispersive; hence, these prisms are applied to the correction of atmospheric dispersion in astronomical optics. Next, a dispersionless multiple-prism array is described. Given the geometrical ﬂexibility of multiple-prism beam expanders, a three-prism dispersionless conﬁguration can be designed easily. From Eq. (5.7), for m ¼ 3 and for an orthogonal beam exit, ψ 2;1 ¼ ϕ2;1 ¼ 0, ψ 2;2 ¼ ϕ2;2 ¼ 0, ψ 2;3 ¼ ϕ2;3 ¼ 0; for a dispersionless conﬁguration, the following condition must be satisﬁed [38,39] ðk 1;1 þ k 1;1 k 1;2 Þ tan ψ 1;1 ¼ ðk 1;1 k1;2 Þk 1;3 tan ψ 1;3

ð5:26Þ

For fused silica (n ¼ 1:45838 at λ ¼ 590 nm), the design of a dispersionless multiple-prism beam expander providing an overall beam magniﬁcation of M 42 is illustrated. In this illustration, the following expansions are selected: k1;1 ¼ k1;2 ¼ 5:2749 which implies that ϕ1;1 ¼ ϕ1;2 ¼ 821 and ψ 1;1 ¼ ψ 1;2 ¼ 42:76701. From Eq. (5.26) ðk 1;1 þ k 1;1 k 1;2 Þ tan ψ 1;1 tan ϕ1;3 ¼ k 1;1 k1;2 n

ð5:27Þ

Fig. 13. Quasi-achromatic fused silica multiple-prism beam expander yields zero dispersion and a beam expansion of M 42:7828 at λ ¼ 590 nm. Drawing is approximately to scale.

338

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

and it can be directly deduced that ϕ1;3 58:06911, ψ 1;3 35:58701, and k 1;3 1:5376, so M ¼ k1;1 k 1;2 k 1;3 42:7828

ð5:28Þ

This class of quasi-achromatic beam expander, with zero dispersion at λ ¼ 590 nm, is directly applicable to the design of narrow-linewidth tunable lasers [38]. The three-prism beam expander is displayed approximately to scale in Fig. 13. Multiple-prism arrays, in their various forms, are applicable to optical instrumentation, such as spectrometers [38], and even astronomical instrumentation [42]. 5.2. Applications to tunable lasers Multiple-prism grating conﬁgurations, as developed for tunable organic lasers [31–34] have been successfully applied to tunable gas lasers [43], optical parametric oscillators [38], and tunable diode lasers [44,45]. In particular, research by Zorabedian [44] on tunable semiconductor lasers demonstrated the advantages of utilizing multiple-prism grating conﬁgurations that enable a closed cavity conﬁguration, in which the laser output is coupled from the output coupler mirror rather than from the reﬂection losses of the diffraction grating. These advantages include reduced output noise and protection from unwanted external back reﬂections. Here, it should be noted that one of the ﬁrst grating-tuned semiconductor lasers, introduced by Fleming and Mooradian [46], did use a closed cavity conﬁguration and expanded the intracavity beam incident on a Littrow grating. 6. Generalized higher-order multiple-prism dispersion equations for laser pulse compression An additional area of optics created by developments in broadly tunable organic dye lasers was prismatic pulse compression [47] or multiple-prism pulse compression [48]. In essence, this area is a direct consequence of the pulse laser linewidth equation 1 ∂Θ Δλ Δθ ∂λ which indicates that greatly reduced intracavity dispersion leads to a very broad emission linewidth. Through a variant of Heisenberg's uncertainty principle, ΔνΔt 1

ð6:1Þ

this broad linewidth implies a very short pulse. This equation will be reconsidered in the next section. Control of the intracavity dispersion and the ability to introduce negative dispersion can enable a severe reduction of intracavity dispersion and cause very broadband emission or very short pulses, as explained by Eq. (6.1). Thus, learning to control the intracavity dispersion becomes very important. Returning to Eq. (5.1), the identity ∇n ϕ2;m ¼ ∇λ ϕ2;m ð∇λ nm Þ 1

ð6:2Þ

can be applied to restate the generalized multiple-prism dispersion as [49,50] ∇n ϕ2;m ¼ H2;m þ ðMÞ 1 ðH1;m 7∇n ϕ2;ðm 1Þ Þ

ð6:3Þ

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

339

where the identity 1 1 k1;m k2;m ¼ ðM 1 Þ

ð6:4Þ

applies. Hence, the complete second derivative of the refraction angle, or ﬁrst derivative of the dispersion ∇λ ϕ2;m , is given by [49] ∇2n ϕ2;m ¼ ∇n H2;m þ ð∇n M 1 ÞðH1;m 7∇n ϕ2;ðm 1Þ Þ þ ðM 1 Þð∇n H1;m 7∇2n ϕ2;ðm 1Þ Þ

ð6:5Þ

the third and higher derivatives are given by Duarte [40,50]. Based on the progression of the higher derivatives, a generalized expression can be found to be ∇rn ϕ2;m ¼ ∇rn 1 H2;m þ ðMÞ 1 ð∇n þ ζÞr 1

ð6:6Þ

where ζ s ¼ ∇sn H1;m 7∇sþ1 n ϕ2;ðm 1Þ

ð6:7Þ

ζ 0 ¼ 1 ¼ H1;m 7∇n ϕ2;ðm 1Þ

ð6:8Þ

Here, it is very important that when writing the expansion in r, in Eq. (6.6), the term ζ 0 ¼ 1 be included as deﬁned in Eq. (6.8). Additionally, in Eq. (6.7) the maximum value of the exponent is s ¼ ðr 1Þ. As an initial example, we write the ﬁrst derivative (r ¼ 1), or angular dispersion ∇1n ϕ2;m ¼ ∇0n H2;m þ ðMÞ 1 ð∇n þ ζÞ0 ∇1n ϕ2;m ¼ ∇0n H2;m þ ðMÞ 1 1 ∇n ϕ2;m ¼ H2;m þ ðMÞ 1 ðH1;m 7∇n ϕ2;ðm 1Þ Þ thus correctly reproducing Eq. (6.3). As a further example, we provide the sixth derivative, for which we set r ¼ 6 in Eq. (6.6) ∇6n ϕ2;m ¼ ∇5n H2;m þ ðMÞ 1 ð∇n þ ζÞ5 ∇6n ϕ2;m ¼ ∇5n H2;m þ ðMÞ 1 ð∇5n ζ 0 þ 5∇4n ζ 1 þ 10∇3n ζ 2 þ 10∇2n ζ 3 þ 5∇1n ζ 4 þ ∇0n ζ 5 Þ ∇6n ϕ2;m ¼ ∇5n H2;m þ ð∇5n M 1 ÞðH1;m 7∇n ϕ2;ðm 1Þ Þ þ 5ð∇4n M 1 Þð∇n H1;m 7∇2n ϕ2;ðm 1Þ Þ þ10ð∇3n M 1 Þð∇2n H1;m 7∇3n ϕ2;ðm 1Þ Þ þ 10ð∇2n M 1 Þð∇3n H1;m 7∇4n ϕ2;ðm 1Þ Þ

þ5ð∇n M 1 Þð∇4n H1;m 7∇5n ϕ2;ðm 1Þ Þ þ ðM 1 Þð∇5n H1;m 7∇6n ϕ2;ðm 1Þ Þ

ð6:9Þ

340

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

Fig. 14. Double-prism pulse compressor.

For the seventh derivative, for which r ¼ 7 in Eq. (6.6), the equation becomes ∇7n ϕ2;m ¼ ∇6n H2;m þ ð∇6n M 1 ÞðH1;m 7∇n ϕ2;ðm 1Þ Þ þ 6ð∇5n M 1 Þð∇n H1;m 7∇2n ϕ2;ðm 1Þ Þ þ15ð∇4n M 1 Þð∇2n H1;m 7∇3n ϕ2;ðm 1Þ Þ þ 20ð∇3n M 1 Þð∇3n H1;m 7∇4n ϕ2;ðm 1Þ Þ þ15ð∇2n M 1 Þð∇4n H1;m 7∇5n ϕ2;ðm 1Þ Þ þ 6ð∇n M 1 Þð∇5n H1;m 7∇6n ϕ2;ðm 1Þ Þ

þðM 1 Þð∇6n H1;m 7∇7n ϕ2;ðm 1Þ Þ

ð6:10Þ

Thus, we have found a systematic, consistent, and even elegant approach to the expression of the higher-order phase derivatives, which are applicable to generalized prismatic pulse compression. 6.1. Applications to laser pulse compression and coherent microscopy The ﬁrst and most direct application of the generalized multiple-prism dispersion theory [35,49] in the ﬁeld of laser pulse compression, is the exact numerical evaluation of dispersion for multiple-prism pulse compressors [51]. In this area, the research of Osvay et al. [52,53] is particularly interesting because it demonstrates close agreement between calculated and measured dispersions for practical double-prism pulse compressors, illustrated in Fig. 14, used to generate femtosecond laser pulses with a duration of 18 fs [53]. In their work, these authors compared their measurements with the values calculated from Eqs. (6.3) and (6.5). In addition to direct applications to laser pulse compression, the generalized multiple-prism dispersion equations described here have been applied in the area of coherent microscopy. In this research, femtosecond pulsed lasers incorporating multiple-prism pulse compressors are used to generate three dimensional micrographs of GaAs/AlGaAs quantum wells [54] and V-groove quantum wires [55]. Further quantum optical applications of prismatic femtosecond lasers are reviewed by Diels and Rudolph [12]. 7. The quantum interferometric connection Dirac ﬁrst applied quantum ideas to macroscopic optics [56] by connecting the concepts of states and probability amplitudes with light beams and two-beam macroscopic interference. In this regard, Dirac should be considered to be the father of quantum optics [38]. The second early example of the application of quantum concepts to macroscopic classical optics was by Feynman who used his quantum path integral formalism to describe the divergence of a Gaussian beam [57]. In Dirac's notation [56], the N-slit interferometric probability amplitude for single-photon propagation from a source (s) through the N-slit array (j) to the interferometric plane (x) is given

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

341

by [58,59] N

〈xjs〉 ¼ ∑ 〈xjj〉〈jjs〉

ð7:1Þ

j¼1

which leads to the interferometric equation [58,59] N

N

j¼1

m¼1

j〈xjs〉j2 ¼ ∑ Ψ ðr j Þ ∑ Ψ ðr m ÞeiðΩm Ωj Þ or, in its alternative form, N

N

j〈xjs〉j ¼ ∑ Ψ ðr j Þ þ 2 ∑ Ψ ðr j Þ 2

j¼1

2

j¼1

N

∑ Ψ ðr m Þ cos ðΩm Ωj Þ

m ¼ jþ1

ð7:2Þ ! ð7:3Þ

where Ψ(rj ) are the wave function amplitudes of the ordinary wave optics as deﬁned by Dirac [56], and the term in parenthesis describes the phase, which includes an exact description of the geometry of the N-slit interferometer [58,59]. Although originally derived for single-photon propagation, this equation has been found through a large number of experiments and measurements to accurately describe the interferometric propagation of ensembles of indistinguishable photons from narrow-linewidth lasers [59–62]. This point is illustrated, for N¼ 3, by the measured interferograms and the calculated interferometric distribution shown in Figs. 15–17. First, Fig. 15 shows a control interferogram measured at an intra interferometric distance of D〈xjj〉 ¼ 7:235 m. Then, Fig. 16 shows a measured interferogram at the same intra interferometric distance with the addition of the diffractive effect caused by a spider web silk ﬁber 15 cm from the interferometric plane. Next, Fig. 17 shows the interferometric distribution calculated from Eq. (7.3) and highlights the superimposed diffractive signal caused by the soft intersection of the silk ﬁber. The agreement between theory and experiment is remarkable [62]. Here, it should be indicated that the interferometric calculation is performed through a cascade approach, ﬁrst introduced in [59]; this approach the silk ﬁber of the spider web to be introduced as two wide slits separated by the diameter of the ﬁber, which is approximately 30 μm [62].

Fig. 15. Measured control interferogram for N ¼ 3 at an intra-interferometric distance of D〈xjj〉 ¼ 7:235 m and a wavelength of λ ¼ 632:8 nm. The slits are 570 μm wide and are separated by 570 μm, from Duarte et al. [62].

342

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

Fig. 16. Measured interferogram for N ¼ 3 at an intra-interferometric distance of D〈xjj〉 ¼ 7:235 m and a wavelength of λ ¼ 632:8 nm. In this case, however, a semi-transparent spider web silk ﬁber, approximately 30 μm in diameter, is inserted at an intra-interferometric distance of D〈xjj〉 ¼ 7:085 m (that is, 15 cm from the interference plane) to induce soft probing of the given interferometric character. The slits are 570 μm wide and are separated by 570 μm, from Duarte et al. [62].

Fig. 17. Calculated interferogram, using Eq. (7.2) for N ¼ 3 at an intra-interferometric distance of D〈xjj〉 ¼ 7:235 m and a wavelength of λ ¼ 632:8 nm. The presence of the spider web silk ﬁber, at a distance of D〈xjj〉 ¼ 7:085 m, is incorporated into the calculation through an interferometric cascade approach [59]. The slits are 570 μm wide and are separated by 570 μm, from Duarte et al. [62].

Thus, the interferogram produced by the interaction of the incident expanded laser beam with the N-slit array propagates for a distance of D〈xjj〉 ¼ 7:085 m prior to illumination of the two wide slits. The interaction with the second diffractive object produced the beautiful interferogram with the superimposed diffraction signal illustrated in Figs. 16 and 17. Here, we should mention that the application of quantum principles in the description of macroscopic optical phenomena is perfectly within the framework of van Kampen's quantum theorems [63].

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

343

In addition to the ability to accurately predict, or reproduce, experimental results, Eq. (7.3) allows the derivation of the generalized diffraction grating equation [64,65] mλ ¼ dð7 sin Θ7 sin Θ′Þ

ð7:4Þ

and the generalized refraction equation for both positive and negative refraction [64,65] 7n1 sin Θ7n2 sin Φ ¼ 0

ð7:5Þ

This generalized refraction equation leads to an even more generalized form of the multipleprism dispersion equation, that is [65], ∇λ ϕ2;m ¼ 7H2;m ∇λ nm 7ðk 1;m k2;m Þ 1 ðH1;m ∇λ nm ð7Þ∇λ ϕ2;ðm 1Þ Þ

ð7:6Þ

where the free 7 sign refers to positive or negative refraction, and the alternative in parenthesis ð7Þ to either a positive ðþÞ or a compensating ð Þ conﬁguration [64]. Furthermore, the N-slit interferometric equation has been used to derive the cavity linewidth equation [66] 1 ∂Θ Δλ Δθ ∂λ which has been shown to be a crucial concept in the development of tunable narrow-linewidth and tunable single-longitudinal-mode laser oscillators. To complete the story, it should be mentioned that the N-slit interferometric equation can also be used to derive the interferometric identity [38] Δλ

λ2 Δx

ð7:7Þ

which in conjunction with de Broglie's expression p ¼ ℏk, leads to Heisenberg's uncertainty principle [38,56] ΔpΔx h

ð7:8Þ

From this form of the uncertainty principle, it can be shown that ΔνΔt 1 follows. As described previously, this expression is central to our discussion of the interaction between intracavity dispersion, emission linewidth, and laser pulse duration. 7.1. Interference and quantum entanglement The generalized interferometric equation, Eq. (7.3), has been used to generate theoretical interferograms, called interferometric characters, for secure free-space optical communications [61,62,68]. In this application, interferometric characters are generated experimentally and are compared with their theoretical counterparts to determine the ﬁdelity of the transmission. Any attempt to classically intercept the interferometric characters results in their catastrophic collapse [61,62,68] and, as discussed previously, even the interception of the interferometric character with subtle means, such as microscopic spider web silk ﬁbers, can be detected. Ultimately, there is a nexus, at a fundamental notational level, between the approach based on the generalized interferometric equation and the more widely used quantum entanglement

344

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

probability amplitude. Returning to the fundamental Dirac principle described by Eq. (7.1), N

〈xjs〉 ¼ ∑ 〈xjj〉〈jjs〉 j¼1

Duarte [69] has recently shown that, for N ¼ 2, this probability amplitude is directly applicable to an interferometric description of quantum entanglement. In this regard, replacing x with the notation for a detector d leads to 〈djs〉 ¼ 〈dj2〉〈2js〉 þ 〈dj1〉〈1js〉

ð7:9Þ

which can then be abstracted to js〉 ¼ j2〉〈2js〉 þ j1〉〈1js〉

ð7:10Þ

Experimentally, this equation can be applied to the description of two indistinguishable quanta that originate at a common source and travel in different directions while passing through different polarizers 1 and 2 [69]. Now, through the Dirac identity jϕ〉 ¼ jj〉〈jjϕ〉, Eq. (7.10) can be expressed as js〉 ¼ jB〉 þ jA〉

ð7:11Þ

where jB〉 ¼ j2〉〈2js〉 and jA〉 ¼ j1〉〈1js〉. Applying the Dirac identity for several particles [56] ja1 b2 c3 :::gn 〉 ¼ ja1 〉jb2 〉jc3 〉:::jgn 〉

ð7:12Þ

which can also be expressed as jX〉 ¼ ja〉1 jb〉2 jc〉3 :::jg〉n

ð7:13Þ

leads directly to jB〉 ¼ jx〉1 jy〉2

ð7:14Þ

jA〉 ¼ jy〉1 jx〉2

ð7:15Þ

and since, from Eq. (7.10), we know that jB〉 a jA〉. The substitution of Eqs. (7.14) and (7.15) into Eq. (7.11) leads to the probability amplitude js〉 ¼ jx〉1 jy〉2 þ jy〉1 jx〉2

ð7:16Þ

where x and y refer to different polarizations and the subscripts refer to quanta 1 and 2. The probability amplitudes of entangled states in this form were ﬁrst discovered by Pryce and Ward [70] and Ward [71] in 1947–1949. Use of the usual normalization and replacement of js〉 by jψ〉 leads directly to a ubiquitous probability amplitude for entangled polarizations 1 jψ〉 ¼ pﬃﬃﬃðjx〉1 jy〉2 7jy〉1 jx〉2 Þ 2

ð7:17Þ

where the 7 allows for different linear combinations. Use of the Dirac identity expressed in Eq. (7.13) leads to the more general Pryce-Ward probability amplitude 1 jψ〉 ¼ pﬃﬃﬃðja〉1 jb〉2 jc〉3 :::jg〉n 7ja′〉1 jb′〉2 jc′〉3 :::jg′〉n Þ 2

ð7:18Þ

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

345

8. Conclusions In this paper, we have highlighted various dispersive techniques crucial to the successful development of narrow-linewidth tunable organic dye lasers. The role of those dispersive techniques in tunable gas lasers, tunable solid state lasers, and tunable diode lasers has been indicated. Particular attention was paid to multiple-prism arrays and the generalized multiple-prism dispersion equation. That equation has been applied here, for the ﬁrst time, to calculate the dispersion associated with direct-vision prisms, also known as Amici prisms, and compound prisms. This calculation was motivated by the use of these prisms in astronomical instrumentation. Following these dispersion calculations, a practical dispersionless multiple-prism beam expander was designed using the same equations, and the versatility of the generalized multiple-prism dispersion theory was thus demonstrated. Next, attention was focused on higher-order dispersions as needed and applied in prismatic pulse compressors for femtosecond lasers. In this regard, recent results obtained by Duarte [40,50] have been extended to obtain a succinct and elegant general equation for the generalized multiple-prism dispersion; this equation is valid up to the rth derivative ∇rn ϕ2;m ¼ ∇rn 1 H2;m þ ðMÞ 1 ð∇n þ ζÞr 1 and explicit versions of this equation are included for the higher derivatives r ¼ 6; 7. The discussion in this paper centers on the cavity linewidth equation 1 ∂Θ Δλ Δθ ∂λ which can be derived from the quantum interferometric equation [38,66] N

N

j〈xjs〉j ¼ ∑ Ψ ðr j Þ þ 2 ∑ Ψ ðr j Þ 2

j¼1

2

j¼1

N

!

∑ Ψ ðr m Þ cos ðΩm Ωj Þ

m ¼ jþ1

This discussion reinforces the interaction between classical optics and quantum optics; although highlighted by Dirac [56] and Feynman [57], this interaction is not always appreciated in today's literature, with the exception of notable contributions, such as those of Lamb [67]. It has been also shown that the generalized N-slit interferometric equation and the probability amplitude for quantum entanglement have a common origin.

References [1] P.P. Sorokin, J.R. Lankard, IBM Journal of Research and Development 10 (1966) 162. [2] F.P. Schäfer, W. Schmidt, J. Volze, Applied Physics Letters 9 (1966) 306. [3] P.N. Everett, 300 W dye laser for ﬁeld experimental site, in: R.C. Sze, F.J. Duarte (Eds.), Proceedings of the International Conference on Lasers '88, STS, McClean, 1989, p. 404. [4] I.L. Bass, R.E. Bonanno, R.H. Hackel, P.R. Hammond, Applied Optics 31 (1992) 6993. [5] L.J. Radziemski, R.W. Solarz, J.A. Paisner (Eds.), Laser Spectroscopy and its Applications, Marcel Dekker, New York, 1987. [6] P.A. Bokhan, et al., Laser Isotope Separation in Atomic Vapor, Wiley-VCH, Weinheim, 2006. [7] L. Goldman, Dye lasers in medicine, in: F.J. Duarte, L.W. Hillman (Eds.), Dye Laser Principles, Academic, New York, 1990 (p. 419). [8] A. Costela, I. García-Moreno, R. Sastre, Medical applications of dye lasers, in: F.J. Duarte (Ed.), Tunable Laser, Applications, CRC, New York, 2009 (p. 227).

346 [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60]

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347 J.F. Ready, R.K. Erf, Laser Applications, Academic, New York, 1984. W. Demtröder, Laserspektroscopie: Grundlagen und Techniken, 5th ed., Springer, Berlin, 2007. W. Demtröder, Laser Spectroscopy: Basic Principles, 4th ed., Springer, Berlin, 2008. J.C. Diels, W. Rudolph, Ultrashort Laser Pulse Phenomena, 2nd ed., Academic, New York, 2006. F.P. Schäfer, Dye Lasers, 3rd ed., Springer, Berlin, 1990. B.H. Soffer, B.B. McFarland, Applied Physics Letters 10 (1967) 266. T.W. Hänsch, Applied Optics 11 (1972) 895. J.K. Robertson, Introduction to Optics: Geometrical and Physical, Van Nostrand, New York, 1955. F.A. Jenkins, H.E. White, in: Fundamentals of Optics, McGraw-Hill, New York, 1957. I. Shoshan, N.N. Danon, U.P. Oppenheim, Journal of Applied Physics 48 (1977) 4495. M.G. Littman, H.J. Metcalf, Applied Optics 17 (1978) 2224. A.A. Michelson, Studies in Optics, Chicago, The University of Chicago, 1927. R.G. Caro, M.C. Gower, C.E. Webb, Journal of Applied Physics D: Applied Physics 15 (1982) 767. M. Sugii, M. Ando, K. Sasaki, IEEE Journal of Quantum Electronics QE-23 (1987) 1458. K.R. German, Applied Optics 20 (1981) 3168. K.W. Kangas, D.D. Lowenthal, C.H. Muller, Optics Letters 14 (1989) 21. D. Sesko, C.G. Fan, C.E. Wieman, Journal of the Optical Society of America B 5 (1988) 1225. C. Wieman, L.W. Hollberg, Review of Scientiﬁc Instruments 62 (1991) 1. I. Newton, Opticks, The Royal Society, London, 1704. D. Brewster, A Treatise on New Philosophical Instruments for Various Purposes in the Arts and Sciences with Experiments on Light and Colours, Murray and Blackwood, Edinburgh, 1813. D.C. Hanna, P.A. Karkkainen, R. Wyatt, Optical and Quantum Electronics 7 (1975) 115. T. Kasuya, T. Susuki, K. Shimoda, Applied Physics 17 (1978) 131. F.J. Duarte, J.A. Piper, Optics Communications 35 (1980) 100. F.J. Duarte, J.A. Piper, Applied Optics 20 (1981) 2113. F.J. Duarte, Optics and Laser Technology 29 (1997) 513. F.J. Duarte, Applied Optics 39 (1999) 6347. F.J. Duarte, J.A. Piper, Optics Communications 43 (1982) 303. F.J. Duarte, J.A. Piper, American Journal of Physics 51 (1983) 1132. F.J. Duarte, J.A. Piper, Optica Acta 31 (1984) 331. F.J. Duarte, Tunable Laser Optics, Elsevier-Academic, New York, 2003. F.J. Duarte, Optics Communications 53 (1985) 259. F.J. Duarte, Progress in Quantum Optics 36 (2012) 29. C.G. Wynne, Monthly Notes of the Royal Astronomical Society 285 (1997) 130. G.Y. Sirat, K. Wilner, D. Neuhauser, Optics Express 13 (2005) 6310. F.J. Duarte, Applied Optics 24 (1985) 1244. P. Zorabedian, Journal of Lightwave Technology 10 (1992) 330. R.W. Fox, L. Hollberg, A.S. Zibrov, Semiconductor diode lasers, in: F.B. Dunning, R.G. Hulet (Eds.), Atomic, Molecular, and Physical Optics, Academic, New York, 1997 (p. 77). M.W. Fleming, A. Mooradian, IEEE Journal of Quantum Electronics QE-17 (1981) 44. W. Dietel, J.J. Fontaine, J.C. Diels, Optics Letters 8 (1983) 4. R.L. Fork, O.E. Martinez, J.P. Gordon, Optics Letters 9 (1984) 150. F.J. Duarte, Optical and Quantum Electronics 19 (1987) 223. F.J. Duarte, Applied Physics B 96 (2009) 809. F.J. Duarte, Optical and Quantum Electronics 22 (1990) 467. K. Osvay, A.P. Kovács, Z. Heiner, G. Kurdi, J. Klebniczki, M. Csatári, IEEE Journal of Selected Topics in Quantum Electronics 10 (2004) 213. K. Osvay, A.P. Kovács, G. Kurdi, Z. Heiner, M. Divall, J. Klebniczki, I.E. Ferincz, Optics Communications 248 (2005) 201. B.A. Nechay, U. Siegner, M. Achermann, H. Bielefeldt, U. Keller, Review of Scientiﬁc Instruments 70 (1999) 2758. U. Siegner, M. Achermann, U. Keller, Measurement Science and Technology 12 (2001) 1847. P.A.M. Dirac, The Principles of Quantum Mechanics, 4th edition, Oxford, London, 1978. R.P. Feynman, A.R. Hibbs, Quantum Mechanics and Path Integrals, McGraw Hill, New York, 1965. F.J. Duarte, Dispersive dye lasers, in: F.J. Duarte (Ed.), High Power Dye Lasers, Springer, Berlin, 1991 (p. 7). F.J. Duarte, Optics Communications 103 (1993) 8. F.J. Duarte, European Journal of Physics 25 (2004) L57.

F.J. Duarte / Progress in Quantum Electronics 37 (2013) 326–347

347

[61] F.J. Duarte, Interferometric imaging, in: F.J. Duarte (Ed.), Tunable Laser Applications, CRC, New York, 2009 (p. 341). [62] F.J. Duarte, T.S. Taylor, A.M. Black, I.E. Olivares, Journal of Modern Optics 60 (2013) 136. [63] N.G. van Kampen, Physica A 153 (1988) 97. [64] F.J. Duarte, American Journal of Physics 65 (1997) 637. [65] F.J. Duarte, Applied Physics B 82 (2006) 35. [66] F.J. Duarte, Applied Optics 31 (1992) 6979. [67] W.E. Lamb, Nuclear Physics B 6 (1989) 197. [68] F.J. Duarte, Optics Communications 205 (2002) 313. [69] F.J. Duarte, Quantum Optics for Engineers, CRC, New York, 2013. [70] M.L. Pryce, J.C. Ward, Nature 160 (1947) 435. [71] J.C. Ward, Some Properties of the Elementary Particles, Oxford University, Oxford, 1949.

Copyright © 2023 COEK.INFO. All rights reserved.