Biaxial crystal α-BaTeMo_2O_9: theory study of large birefringence and wide-band polarized prisms design

Abstract

α-BaTeMo(2)O(9) is a novel biaxial crystal with wide-band transmittance spectrum. The refractive index dispersion curves and birefringence of the α-BaTeMo(2)O(9) crystal were obtained in spectral range of 0.4~5 μm. The origin of the birefringence for the crystal has been calculated and interpreted on the basis of the crystal structure combined with theoretical studies. The polarized directions and formulations of refractive index of optical waves in biaxial α-BaTeMo(2)O(9) were investigated by solving the refractive index ellipsoid equations. Furthermore, polarized prisms based on the α-BaTeMo(2)O(9) crystal used in spectral ranges of 0.4~2.7 μm and 0.48~4.5 μm were designed and characterized. The extinction ratios of both prisms were determined to be larger than 10000:1, which would satisfy the practical requirements. The impacts on extinction ratio for biaxial and uniaxial crystals were also discussed. To our knowledge, it is the first report about biaxial crystals for the polarized prisms, and the results show that the α-BaTeMo(2)O(9) crystal is a promising material for polarized optical components, especially in the range of 3~5 μm.

Investigating the Optical Properties of a Laser Induced 3D Self‐Assembled Carbon–Metal Hybrid Structure

“…Our studies show that this novel hybrid metamaterial features a linear birefringence mainly caused by the orthorhombic carbon phase. The linear birefringence remains nearly constant (Δ n = 0.09 ± 0.005) over a spectral range of 400–700 nm, which is generally comparable to naturally birefringent materials, but it outperforms other orthorhombic crystalline structures . Furthermore, the combination of the field enhancement introduced by the plasmonic Au–Ag nanoparticle inclusions and the birefringence suggest a strong potential for opto‐electronics, nanophotonic, nonlinear optical experiments, and applications …”

Second harmonic generation from the novel polar polymorph α/β-BaTeMo2O9 phases

“…Noncentrosymmetric polar inorganic oxide materials are promising candidates for second order nonlinear optical applications namely second harmonic generation (SHG). [1][2][3] In the recent years there is potential interest in nding novel materials which can produce visible, ultraviolet and infra-red laser radiation at wavelengths that are presently inaccessible via conventional sources for many industrial, medical, biological and entertainment applications. [4][5][6] Noncentrosymmetric polar inorganic oxides are technologically important for several applications, such as piezoelectricity, nonlinear optical properties, ferroelectricity and pyroelectricity.…”

“…1 The newly discovered phase motivated several researchers to investigate the unique properties of this phase. 2,3,14 Recently, Raman spectra using pulsed laser diode pumped Nd:YAG/Cr 4+ :YAG was reported for a-BaTeMo 2 O 9 phase, 14 they found that the high energy output pulse have potential application in medical treatment and laser ranging. 14 Using two continuous wave lasers 808 and 1064 nm as photoinducing sources Majchrowski et al 2 have measured the SHG at the wavelength 1064 nm under photoinducing treatment of monoclinic piezoelectric b-BaTeMo 2 O 9 .…”

“…An ab initio plane-wave pseudopotential total energy package CASTEP within the generalized gradient approximation (PBE-GGA) was used to calculate the refractive index and the birefringence of a-BaTeMo 2 O 9 in the spectral range of 0.4-5.0 mm. 3 From the above it is clear that there exists some experimental and theoretical work on b-BaTeMo 2 O 9 and a-BaTeMo 2 O 9 phases [1][2][3][7][8][9][10][11][12][13][14] we feel that there is a dearth information on the second harmonic generation and the microscopic rst hyperpolarizability. Most the measurements of the SHG for b-BaTeMo 2 O 9 and a-BaTeMo 2 O 9 phases were performed on powders without details descriptions about the complex second-order nonlinear optical susceptibility tensors, moreover no information regarding the microscopic rst hyperpolarizability terms which cumulatively yield a bulk observable second order susceptibility term, c (2) ijk (u), which in turn is responsible for the high SHG response.…”

Spin-polarized Second Harmonic Generation from the Antiferromagnetic CaCoSO Single Crystal

“…The transformation of frequencies within the wide spectral range of electromagnetic radiation (between 1–15 μm) for ultrafast lasers (from picoseconds up to femtoseconds) and large power densities can lead to significant progress in laser engineering. The method used for such frequency transformations is usually the generation of harmonic frequencies by employing high quality NLO crystals possessing large second optical susceptibilities89. In particular, the main method employed for frequency transformation is the second harmonic generation (SHG), where organic and inorganic crystals are now among the best1011.…”