Spectroscopic Characterization and Laser Performance of Diffusion Doped Cr2+:ZnS

Diode and fibre pumped Cr2+:ZnS mid-infrared external cavity and microchip lasers

“…1a and 1c, making use of the known upper and ground level partition functions ratio z 2 =z 1 ¼ 0:66. Here E ZFL is the energy of the zero phonon line of the corresponding transition measured in [3,4] from the low-temperature fluorescence spectra, k is the Boltzmann constant, and T is the temperature. Our value for the peak absorption cross-section of a ¼ 1:6 Â 10 ÿ18 cm 2 at l ¼ 1690 nm for Cr 2þ : ZnS [18] agrees reasonably well with the value of a ¼ 1:0 Â 10 ÿ18 cm 2 obtained using the absorption coefficient and the known concentration of Cr 2þ in [19].…”

“…Since then, this class of lasers has attracted a lot of attention and laser demonstrations over the 2 -3 mm spectral region in CW, free-running long pulse, Q-switched and mode-locked regimes of operation were reported for Cr:ZnS [3,4], Cr:ZnSe [5 -9], Cr : Cd 1ÿx Mn x Te [10] and Cr:CdSe [11] crystals.…”

“…In this study we extend our efforts to develop high optical density and high quality Cr 2þ : ZnS and Cr 2þ : ZnSe crystals synthesised by chemical transport reaction from the gas phase and activated by the diffusion doping, additive colouration method [3,4]. Other key objectives of this research have been to provide the first demonstration of CW lasing of Cr 2þ : ZnS crystals under direct fibre and diode laser excitation, and specifically investigate the feasibility of Cr 2þ : ZnS and Cr 2þ : ZnSe crystals lasing in a microchip configuration under CW Er-fibre laser pumping.…”

En route to electrically pumped broadly tunable middle infrared lasers based on transition metal doped II–VI semiconductors

“…After pioneering publications [10,11], mid-IR laser activity near 2-5 mm has been reported for Cr 2+ :ZnS [10][11][12][13][14], Cr 2+ :ZnSe [10][11][12][13][14][15][16][17][18][19][20][21][22], Cr 2+ :Cd 1Àx Mn x Te [23], Cr 2+ :CdSe [24], and Fe 2+ :ZnSe [25] crystals. Recently we optimized technology for two-stage ZnS and ZnSe crystal preparation [12,13,26].…”

“…Recently we optimized technology for two-stage ZnS and ZnSe crystal preparation [12,13,26]. In the 1st stage, undoped single crystals were synthesized by a chemical transport reaction from gas phase using iodine gas transport scheme.…”