Multicolor lasers using birefringent filters: experimental demonstration with Cr:Nd:GSGG and Cr:LiSAF

Abstract

Abstract:In this study, we numerically and experimentally investigate application of birefringent filters (BRFs) as frequency selective elements in multicolor lasers. A BRF plate made out of crystalline quartz with an arbitrarily oriented optical axis has been explored. Simulation results have shown that compared to regular BRFs where the optical axis lies in the plane of the plates surface, a BRF with an optical axis pointing out of its surface enables design flexibility in filter parameters, providing access to a wider set of free spectral range and bandwidth values. As a result, multicolor operation could be obtained in many wavelength pairs using a single BRF plate. In the experiments a 3-mm thick quartz BRF with an optical axis 45° to the surface plane has been used. With Cr:Nd:GSGG as a laser medium two-color and three-color cw laser operation has been demonstrated in 11 and 3 different transition combinations, respectively. Moreover, two-color laser operation has been demonstrated in 10 different wavelength pairs in Cr:LiSAF. To our knowledge, this study is the first detailed investigation and experimental demonstration of BRFs with tilted optical axis for multicolor operation of solid-state lasers. Compared to other methods, BRFs enable a rich selection of transition pairs and also the ratio of the power in each line could be regulated by fine adjustment of the rotation angle. Implementation of tilted-axis BRFs should boost development of efficient and low-cost multicolor lasers in other gain media as well. 449-451 (1997). 6. S. Pan, X. Zhao, and C. Lou, "Switchable single-longitudinal-mode dual-wavelength erbium-doped fiber ring laser incorporating a semiconductor optical amplifier," Opt. Lett. 33(8), 764-766 (2008). 7. C. W. Chow, C. S. Wong, and H. K. Tsang, "All-optical NRZ to RZ format and wavelength converter by dualwavelength injection locking," Opt. Commun. 209(4-6), 329-334 (2002). 7231-7242 (2007). 10. J. B. Abshire, "Pulsed multiwavelength laser ranging system for measuring atmospheric delay," Appl. Opt.19 ( 202-208 (1985). 33. S. Zhu, "Birefringent filter with tilted optic axis for tuning dye lasers: theory and design," Appl. Opt. 29(3), 410-415 (1990). 34. X. Wang and J. Yao, "Transmitted and tuning characteristics of birefringent filters," Appl. Opt. 31(22), 4505-4508 (1992). 35. H. Wu, C. Zhang, and X. Bai, "A complete description of polarization and transmission of nonnormal incident rays in a uniaxial birefringent plate with arbitrary optic axis," Opt. Commun. 283(21), 4129-4134 (2010).

Efficient, diode-pumped, high-power (>300W) cryogenic Yb:YLF laser with broad-tunability (995-10205 nm): investigation of E//a-axis for lasing

“…Moreover, output powers exceeding 100 W was obtained in dual-wavelength operation, which is, to our knowledge, is one of the highest output powers obtained in this regime [59]. It is clear that, with properly designed birefringent tuning elements optimized for multicolor laser operation, cryogenic Yb:YLF gain media could also be used in generating high power multicolor lasing in both cw [59,60] and cw mode-locked [61][62][63] operation regimes. Fig.…”

Frequency-comb-based laser system producing stable optical beat pulses with picosecond durations suitable for high-precision multi-cycle terahertz-wave generation and rapid detection

“…There exist lasers that directly output multiple laser lines. Both continuous wave and pulsed operations of such lasers have been demonstrated [10,11]. However, the spectral profile of the gain medium and the filters, which are used for line selection, determine the frequency difference between the laser lines.…”

Off-surface optic axis birefringent filters for smooth tuning of broadband lasers

“…This is in general very useful, since it enables optimization of performance for different applications. As an example, a recent study demonstrated advantages of off-surface optic axis BRFs in multicolor lasing [9,20].…”

“…On the other hand, as several earlier studies with quartz birefringent filters has already shown, this particular case is not really optimum for many applications. Compared to regular birefringent filters, BRFs with optic axis pointing out of its surface provides a much broader set of filter parameters (named as diving optic axis birefringent filters or off-surface optic axis birefringent filters in the literature) [1, 3,6,9]. In particular, wisely designed off-surface optic axis birefringent plates could: (i) generate larger FSR values, (ii) provide a smoother variation of modulation depth as the wavelength is tuned, (iii) enable faster tuning rates, and (iv) posses a larger range of usable filter rotation angles.…”