High-energy room-temperature Fe²⁺:ZnS laser

Abstract

Characteristics of a room temperature laser on polycrystalline ZnS:Fe2+ subjected to diffuse doping from two sides were investigated. The sample was pumped by a non-chain electrodischarge HF laser with the FWHM duration of the radiation pulse of ~140 ns. The diameter of the pumping radiation spot on the surface of the crystal was 3.8 mm. Further increases in the size of the pumping spot were limited by parasitic generation arising due to a high concentration of Fe ions in the near-surface layer of the sample at a relatively small depth of doping (short length of active medium). The generation energy of 25.5 mJ was obtained at a slope efficiency of 12% with respect to the energy incident on the sample. Characteristics of lasers on polycrystalline ZnS:Fe2+ and ZnSe:Fe2+ have been compared in equal pumping conditions. The slope efficiencies of ZnSe:Fe2+ and ZnS:Fe2+ lasers with respect to the absorbed energy were 34% and 20%, respectively. At equal pumping energy absorbed in the samples, the duration of the ZnSe:Fe2+ laser radiation pulse was longer than that of the ZnS:Fe2+ laser. Possibilities of increasing the efficiency of ZnS:Fe2+ laser operation at room temperature by improving the technology of sample manufacturing and reducing the duration of the pumping pulse are discussed in this letter.

Generation of octave-spanning mid-infrared pulses from cascaded second-order nonlinear processes in a single crystal

“…Further energy scaling in a longer KTA crystal would be expected with sacrifice of reduced bandwidth. Nevertheless, this 2.2–5.0 μ m broadband pulse can seed a Fe 2+ :ZnSe CPA laser 48 , 49 , 51 .…”

Fabrication and characterization of IR‐transparent Fe2+ doped MgAl2O4 ceramics

“…The energy level 5 D of the Fe 2+ ion splits into two levels, 5 E and 5 T 2 and it is suggested that the transition 5 T 2 → 5 E can be used for the mid‐IR laser oscillation similar to Fe 2+ :ZnSe and Fe 2+ :ZnS . Compared with Fe‐doped chalcogenides, polycrystalline Fe 2+ :MgAl 2 O 4 ceramic gain medium can possess a higher volume of active ions due to the absence of the thermal diffusion process of iron from the surface of the sample to a depth of ~1.5 mm at a doping concentration of ~10 19 cm −3 …”

Structure-Property Correlation in Ir Transparent Zinc Sulphide (Zns) Ceramics Under Chemical Vapour Deposited & Hot Iso-Statically Pressed Conditions

“…However, the major challenge is achieving the transmission to the close theoretical density >99.9% and retaining the grain size as less as possible to attain superior optical and mechanical properties. Although, previous researchers have studied optical and structural properties of IR transparent polycrystalline ZnS and other ceramics, only few studies are reported room temperature electrical properties, and no report is found on high temperature (500oC) impedance spectroscopic studies [4][5][6][7][8][9][10][11][12][13].…”