Room‐temperature tunable mid‐infrared lasers on transition‐metal doped II–VI compound crystals grown from vapor phase

Abstract

Seeded free growth method with physical transport was used for preparation of large-size II-VI single crystals uniformly doped by transition metals directly during the growth. The grown crystals possess small intrinsic losses. Based on these crystals new results on development of mid-IR lasers were achieved. With the CdSe:Cr crystal pumped at the room temperature (RT) by a continuous wave (CW) 1.908-mm thulium fiber laser, output laser power at 2.6 mm was increased up to 1.7 W. CW lasing from the ZnSe:Fe crystal was achieved using the 1 Introduction The market need of effective solidstate broadly tunable mid-infrared lasers for 2-5 mm spectral range is well known. This range stays difficult for quantum cascade lasers in spite of the last great results. The most popular laser now is an optical parametric oscillator. However it works only in pulse periodic mode because it utilizes nonlinear effect. The II-VI compounds doped by transition metals are certainly interesting as active materials for mid-infrared lasers [1,2]. The advantages of these lasers include broad tuning of lasing wavelength, room temperature (RT) operation, high efficiency, and capability to produce the high quality laser beam of 1-10 W output power.Most of transition-metal doped II-VI compound crystals were prepared either by Bridgman method or a solid-state diffusion method. The latter includes growth of a pure crystal preferably from vapor phase and doping of it by thermal diffusion of transition metal through the crystal surface. The crystals prepared in this way are characterized by great intrinsic losses due to the high concentration of background defects. To overtop these intrinsic losses they need to use highly doped crystals. But the higher doping concentration,

Room temperature high energy Fe:ZnSe laser pumped by non-chain pulsed HF laser

“…It is necessary to pump Fe:ZnSe laser with a Q switched solid state laser for high efficiency at room temperature, but the maximal energy of Q switched solid state laser at 3μm wavelength range is only 35mJ. So the maximal radiation energy of Fe:ZnSe laser excited by Q switched solid state laser does not exceed 6mJ [8] . Non-chain discharged HF laser has unlimited energy for pumping Fe:ZnSe laser application.…”

Spectroscopy and mid-IR lasing of Cr2+ions in ZnSe/ZnS crystals under visible excitation

“…Technological advancements in gain media based on transition metal (TM) doped II-VI crystals have led to room temperature (RT) broadly tunable laser systems with emission covering the 2-6 µm spectral range [1,2,3,4,5] . Among these gain media, chromium doped ZnSe and ZnS have attracted the most attention due to their unique spectroscopic characteristics.…”

Properties and optical application of polycrystalline zinc selenide obtained by physical vapor deposition

“…Эти методы не позволяют получить однородные крупные кристаллы высокого оптического качества, что необходимо для реализации предельных значений по мощности и эффективно-сти непрерывной генерации. Крупные кристаллы были выращены из паровой фазы методом физического транспорта [8,9]. Рост осуществлялся из раздельных источников паров ZnSe и CrSe.…”