Post-processing ZnSe optical fibers with a micro-chemical vapor transport technique

Abstract

Polycrystalline zinc selenide optical fibers and fiber lasers are expected to provide powerful capabilities for infrared waveguiding and laser technology. High pressure chemical vapor deposition, which is the only technique currently capable of producing zinc selenide optical fibers, leaves a geometric imperfection in the form of a central pore which is detrimental to mode quality. Chemical vapor transport with large temperature and pressure gradients not only fills this central pore but also encourages polycrystalline grain growth. Increased grain size and a reduction in defects such as twinning are demonstrated with transmission electron microscopy, Raman spectroscopy, and X-ray diffraction, supporting that high-quality material is produced from this method. Finally, the mode structure of the waveguide is improved allowing most of the guided optical intensity to be centrally positioned in the fiber core. Loss as low as 0.22 dB/cm at 1908nm is demonstrated as a result of the material improvement.

Single-phase CZTSe via isothermal recrystallization in a KI–KCl flux

“…The peak at 257 cm −1 (LO) in the Raman spectrum of the 1st point corresponds to the zinc selenide phase. 32 On the Raman spectra of points 2 and 3, one can clearly distinguish peaks located at 172-175 cm −1 and 194-197 cm −1 , which, according to the literature data, belong to the kesterite structure of CZTSe. It is known that the characteristic peak located at 194-197 cm −1 refers to the A mode resulting from the Se vibration in the CZTSe structure.…”

Radiative recombination in zinc blende ZnSe nanocrystals ion-beam synthesized in silica

“…for example, red-green-blue laser diodes [2,3], mid-infrared fibers [4,5], optically controlled switches [6], sensors [7], non-linear optical devices [8], laser screens and thin film transistors [9], lenses and dielectric mirrors for infrared laser [10], tunable mid-IR laser sources [11]. Moreover, ZnSe NCs have attracted interest due to its high luminescence quantum yield up to 50%-60% which, additionally, can be significantly increased by doping [12][13][14][15][16].…”