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.

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.

NV diamond laser.

For the first time, lasing at NV centers in an optically pumped diamond sample is achieved. A nanosecond train of 150-ps 532-nm laser pulses was used to pump the sample. The lasing pulses have central wavelength at 720 nm with a spectrum width of 20 nm, 1-ns duration and total energy around 10 nJ.

Experimental and Ab Initio Studies of Intrinsic Defects in "Antizeolite" Borates with a Ba(BO) Framework and Their Influence on Properties.

The porous Ba(BO) framework of the so-called "antizeolite" borates with channels along the axis is capable of accommodating various guest anionic groups, e.g. [BO], [F], [F], and [(Li,Na)F].

Nature of the Color of Borates with "Anti-Zeolite" Structure.

Crystals of the Mn Ba(BO)F phase were grown from a high-temperature solution. This new fluoride borate is built of positively charged [Ba(BO)] blocks, the so-called "anti-zeolite" pattern. Using X-ray single-crystal diffraction, the bulk atomic arrangement in the centrosymmetric tetragonal unit cell in I4/ mcm could be elucidated.

Growth and Optical Properties of LiNaBa(BO)F Fluoride Borates with "Antizeolite" Structure.

Studied LiNaBa(BO)F (P4bc) solid solution belongs to the new class of "antizeolite" borates with [Ba(BO)] cation pattern, which contains channels filled by anionic clusters. Optical-quality crystals were grown from the compositions with different sodium-lithium ratio. The results of Rietveld refinement based on powder data demonstrate linear increase of parameter a and unit cell volume with Na/(Na + Li) ratio in cation site.

Synthesis, Structural, Thermal, and Electronic Properties of Palmierite-Related Double Molybdate α-CsPb(MoO).

CsPb(MoO) crystals were prepared by crystallization from their own melt, and the crystal structure has been studied in detail. At 296 K, the molybdate crystallizes in the low-temperature α-form and has a monoclinic palmierite-related superstructure (space group C2/m, a = 2.13755(13) nm, b = 1.

Crystal Growth, Structure, and Optical Properties of LiGaGe2Se6.

Large single crystals of LiGaGe2Se6 were grown, and their structure and linear optical properties were studied. According to XRD results there is some disorder because of the Li ion fluctuation and their redistribution along two cationic sites. The shape of the fundamental absorption edge versus temperature was analyzed, and direct band gap values were estimated from the Tauc plots.

Pressure-Stimulated Synthesis and Luminescence Properties of Microcrystalline (Lu,Y)₃Al₅O₁₂:Ce³⁺ Garnet Phosphors.

The Lu2.98Ce0.01Y0.

Structures and optical properties of two phases of SrMgF4.

SrMgF4 has an extremely large bandgap Eg of 12.50 eV as obtained from reflection dispersion. The symmetry of this crystal is monoclinic P21 at room temperature and transforms to the orthorhombic Cmc21 phase near 478 K as the temperature increases.

Nd:YAG pumped nanosecond optical parametric oscillator based on LiInSe2 with tunability extending from 4.7 to 8.7 microm.

LiInSe(2) is one of the few (only 5) non-oxide nonlinear optical crystals whose band-gap (2.86 eV) and transparency allowed in the past nanosecond optical parametric oscillation in the mid-IR without two-photon absorption for a pump wavelength of 1064 nm. However, the first such demonstration was limited to the 3.

Frequency doubling of CO2 laser radiation at 10.6 microm in the highly nonlinear chalcopyrite LiGaTe2.

Type-I phase matching for second-harmonic generation at 10.6 microm in LiGaTe(2) is demonstrated by using a tunable single-frequency continuous-wave CO(2) laser, and the nonlinear coefficient of LiGaTe(2) is determined from comparison with AgGaSe(2). The effective nonlinearity of LiGaTe(2) for this process amounts to 34.

LiInSe2 nanosecond optical parametric oscillator.

Optical parametric oscillation using the new lithium selenoindate nonlinear crystal is reported for what is to our knowledge the first time. A 17 mm long, type II phase-matched sample is pumped by a 10 ns Nd:YAG laser. The minimum pump energy threshold is 3 mJ for a signal-resonant configuration.

Widely tunable continuous-wave mid-infrared radiation (5.5-11 microm) by difference-frequency generation in LiInS2 crystal.

The first demonstration, to the best of our knowledge, of continuous-wave (cw) difference-frequency generation (DFG) in LiInS2 crystal is reported. Wide spectral coverage (5.5-11.