NaBa(BO)F (NBBF) dichroic crystals: optical properties and dielectric permittivity.

Three NaBa(BO)F crystals were grown in the BaO-BaF-BO-NaO system from three different compositions of high-temperature solution. With the use of optical spectroscopy, energy-dispersive X-ray spectroscopy, and the Schering bridge method it was found that the crystals revealed sharp differences in their optical and dielectric properties. The relative permittivity of the crystals in direction perpendicular to the optical axis reached 319(5).

Laser induced damage threshold of GaSe with antireflection microstructures at a wavelength of 5 µm.

Large GaSe crystals were grown and various antireflection microstructures (ARMs) were fabricated on their cleaved surfaces using optimized femtosecond laser ablation, which provided the antireflection effect in a wide wavelength range of 4-16 µm. The influence of ARMs created on the GaSe surface on the change of the laser-induced damage threshold (LIDT) of the crystal at a wavelength of 5 μm was evaluated. The 5-µm Fe:ZnMgSe laser with the pulse duration of 135 ns was used for the LIDT test in conditions close to single pulse exposure.

Laser-Induced Periodic Surface Structures on Layered GaSe Crystals: Structural Coloring and Infrared Antireflection.

We study structural and morphological transformations caused by multipulse femtosecond-laser exposure of Bridgman-grown ϵ-phase GaSe crystals, a van der Waals semiconductor promising for nonlinear optics and optoelectronics. We unveil, for the first time, the laser-driven self-organization regimes in GaSe allowing the formation of regular laser-induced periodic surface structures (LIPSSs) that originate from interference of the incident radiation and interface surface plasmon waves. LIPSSs formation causes transformation of the near-surface layer to amorphous GaSe at negligible oxidation levels, evidenced from comprehensive structural characterization.

Evolution of Structures and Optical Properties in a Series of Infrared Nonlinear Optical Crystals LiAgInSe (0 ≤ ≤ 1).

In this work, a number of new infrared nonlinear optical (NLO) crystals of LiAgInSe, in which the ratio of Li/Ag varies in a wide range from 0 to 1, are investigated. Structural analysis reveals that the space group of LiAgInSe evolved from 4̅2 in AgInSe to Pna2 in LiInSe as increases from low values (0, 0.2, 0.

Thermophysical properties of lithium thiogallate that are important for optical applications.

Lithium thiogallate LiGaS is one of the most common nonlinear crystals for mid-IR due to its extreme beam strength and wide transparency range; however, its thermophysical properties have not yet been practically studied. Large crystals of high optical quality are grown. DTA revealed features at 1224 K below melting point (1304 K) that are associated with the oxygen containing compounds of the LiGaO S type.