Continuous-wave broadly tunable high-power Cr:CdS laser

Abstract

We report spectroscopic characteristics and laser properties of the mid-infrared active laser medium Cr2+:CdS. Temperature-dependent absorption, luminescence and lifetime measurements of the 5E exited state allow determination of peak emission cross section value of 1.35 × 10−18 cm2 in σ-polarization at room temperature. Lifetime values vary from 7.6 µs at 8 K to 0.48 µs at 320 K, corresponding to 22 % quantum yield at 285 K. Under Tm-fiber laser pumping, the continuous-wave output reached 1.8 W at 2.5 μm with 35.5 % slope efficiency. With a single CaF2 prism, the CW Cr2+:CdS laser could be tuned from 2.240 to 3.285 µm.

In Situ Low-Temperature Chemical Bath Deposition of CdS Thin Films without Thickness Limitation: Structural and Optical Properties

“…In addition, the CdS compound is one of the most suitable partners for heterojunction solar cells as a window layer when used in association with absorber layers like cadmium telluride (CdTe), copper indium gallium selenide/sulfide (CIGS), kesterites (CZTS) [7], or perovskites as an electron transport layer [8][9][10]. CdS also has potential applications in several fields, such as photocatalysis [11], laser [12,13], light-emitting diodes, and field effect transistors [14].…”

Ultrashort pulse generation in the mid-IR

“…Figure 3 summarizes some of the main sources which are based on semiconductor and solid-state gain media as well as parametric processes, capable of operating in and between the two high atmospheric transmission windows (large absorption interval occurs from 5-8 µm, so two transparency regions can be considered, at 3-5 µm and 8-14 µm). There is a wide array of approaches to generate coherent long wavelength light, with many gain materials, be it through frequency conversion or coherent 70 shifting in liquids, gases and solids and we cannot do justice to all these fantas-tic solutions. Throughout the review we will identify the most well established and/or promising laser sources/amplifiers, giving a very brief historical perspective, detailing important characteristics and presenting the state-of-the-art as well as an outlook.…”

“…The crystal used for this one-of-akind laser was so hygroscopic that it had to be kept in a dry atmosphere with [59,60,61,62,63,64,65,66,67] -were only produced with sufficient quality, and made to lase, in the mid 1990s at Lawrence Livermore National Laboratory [68]. The first lasing action in Cr 2+ :CdSe was reported in 2007 [69] and complete spectroscopic characterization of Cr 2+ :CdS has been reported only this year [70]. Cr:ZnTe is 225 for the moment left rather unstudied [71].…”

“…Kerr-lens mode-locking was achieved [105,106] and resulted in pulses as Mode-locking operation in SESAMs and based on the Kerr effect in Cr 2+ :ZnS 300 shortly followed in 2011 and 2013 [107,108]. It is questionable whether modelocked operation of Cr:CdS will be achieved owing to the short lifetime of the material at room temperature (480 ns) [70]. Mode-locked operation was shown in Cr 2+ :CdS at cryogenic temperature due to the lengthening of the excited state lifetime (7.8 µs at 8 K), but the technical requirement for such low tem-305 peratures might prevent widespread interest with Cr 2+ :CdS.…”

Spectroscopic and laser properties of Cr2+ ions in Zn1−xMgxSe solid solutions

“…In the wavelength range around 2.5 lm, the chromium doped materials as ZnSe:Cr 2+ , ZnS:Cr 2+ [1][2][3][4]8,9], CdSe:Cr 2+ [10,11], CdS:Cr 2+ [12,13], CdTe:Cr 2+ [14,15] were studied and the continuous-wave as well as pulsed laser regime, efficient wavelength tunability, and moreover mode-locked regime [16,17] was successfully demonstrated. As the spectroscopic properties of TM 2+ ions are significantly influenced by their local environment in the matrix, the additional possibility to modify their properties is using the solid solutions approach.…”