Electronic, linear, and nonlinear optical properties of III-V indium compound semiconductors

Lithium borate Li3B5O8(OH)2 with large second harmonic generation and a high damage threshold in the deep-ultraviolet spectral range

The electronic structure and linear and nonlinear optical susceptibility dispersions of lithium borate Li₃B₅O₈(OH)₂ are comprehensively investigated. The investigation is achieved on Li₃B₅O₈(OH)₂ in the form of single crystals, taking into account the influence of the packing of the structural units on the linear and nonlinear optical susceptibility dispersion. The calculations highlight that the BO₃ structural unit packing is the main source of the large birefringence in Li₃B₅O₈(OH)₂ due to the high anisotropic electron distribution, and, hence, it affects the macroscopic second harmonic generation (SHG) coefficients. This work provides a new path for the design of UV-NLO materials with high SHG efficiencies and short cutoff edges by introducing an alkali metal into borates. The large SHG is due to hyperpolarizability formed by co-parallel BO₃ triangle groups. The absorption edge of Li₃B₅O₈(OH)₂ occurs at λ = 190 nm and the optical band gap is estimated to be 6.52 eV, which is in good agreement with the experimental data (6.526 eV). The energy gap value confirms that Li₃B₅O₈(OH)₂ exhibits an exceptional laser damage threshold and is expected to produce coherent radiation in the deep-ultraviolet (DUV) region. The obtained value of SHG at λ = 1064 nm is about 1.5 times that of the well-known NLO crystal KH₂PO₄ (KDP) at λ = 1064 nm and 3.5 times that of KDP at λ = 190 nm, which is transparent down to the DUV region. Thus, one can conclude that the combination of an alkali metal with borates leads to the generation of promising DUV-NLO crystals. This work is aimed at qualitative and quantitative investigation to report a reliable SHG value and provide details of the NLO tensor for bulk Li₃B₅O₈(OH)₂ single crystals.

The influence of oxygen vacancies on the linear and nonlinear optical properties of Pb7O(OH)3(CO3)3(BO3)

We have investigated the influence of the oxygen vacancy on the linear and nonlinear optical properties and the microscopic first hyperpolarizability of asymmetric Pb₇O(OH)₃(CO₃)₃(BO₃).

Ab initio study on optical properties of glycine sodium nitrate: a novel semiorganic nonlinear optical crystal

The electronic structure, and linear and nonlinear optical susceptibilities of crystalline glycine-sodium nitrate (GSN) has been studied using the full potential linear augmented plane wave method within density-functional theory.

Linear and nonlinear optical properties for AA and AB stacking of carbon nitride polymorph (C3N4)

The linear and nonlinear optical susceptibilities of AA and AB stacking of the carbon nitride polymorph were calculated using the all electron full potential linear augmented plane wave method based on density functional theory.

Electronic structures and optical properties of Ca5(BO3)3F: a systematical first-principles study

A first-principles study of the electronic structure, the linear optical properties and second-order NLO properties of calcium fluoroborate (Ca(5)(BO(3))(3)F, or CBF) crystal has been performed within density functional theory and the independent-particle approximation. The results indicate that the calculated birefringence Δn and the second-order susceptibilities are very coincident with the experimental measured values, and the χ((2)) curves show stronger anisotropy than the linear optical properties. Further analysis based on the spectral and spatial decomposition of χ((2)) reveals that the main sources of the SHG response of CBF are from the planar BO(3) groups (74%-77%) and Ca(2+) cations (23%-26%) and can be attributed to the interband electronic transition from the nonbonding O 2p states to the B 2p and Ca 4s4p states. The packing arrangement of BO(3) is the principal contributor to the significant differences among SHG tensors in CBF. Meanwhile, for a certain crystal CBF, the SHG tensors' trend can be the trend of the optical transition matrix elements, which are high when the corresponding subscript directions have more parallel BO(3) triangular planes in the structure.