Two Covalent Ultraviolet Nonlinear Optical Crystals
| Autor: | Junhua Luo, Zheshuai Lin, Sangen Zhao, Shuai Liu, Yonggang Wang, Yanqiang Li, Qingran Ding, Lina Li, Gaomin Song, Qian Zhang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010405 organic chemistry
Chemistry Organic Chemistry Far-infrared laser Second-harmonic generation General Chemistry Laser science 010402 general chemistry Laser medicine.disease_cause 01 natural sciences Biochemistry 0104 chemical sciences law.invention Crystal Crystallography Covalent bond law medicine Absorption (electromagnetic radiation) Ultraviolet |
| Zdroj: | Chemistry – An Asian Journal. 15:775-779 |
| ISSN: | 1861-471X 1861-4728 |
| DOI: | 10.1002/asia.201901562 |
| Popis: | Nonlinear optical (NLO) crystals are the vital components of laser science and technology, as they can convert lasers in common wavelengths into new wavelength bands for ultraviolet (UV), IR, and even terahertz laser output. Known UV NLO crystals mainly focus on crystals containing cations, but covalent crystals have rarely been reported. Here we report two covalent NLO crystals, B2 O3 I and B2 O3 II. According to the first-principles calculations, B2 O3 I and II have extremely short absorption edges of about 134 nm and 141 nm, large NLO coefficients of d22 =1.38 pm/V and d24 =0.702 pm/V, as well as sufficient birefringences of 0.037 and 0.031, respectively. Notably, the absorption edges are almost the shortest among NLO crystals. Meanwhile, the NLO coefficients are evidently larger than that of another well-known covalent NLO crystal α-SiO2 and are comparable to those of the commercial UV NLO crystal LiBO3 with Li+ cation. Furthermore, the birefringences are significantly larger than that of α-SiO2 , which are favorable to the phase matching for both crystals. These results reveal that B2 O3 I and B2 O3 II are excellent candidates for UV NLO applications. In-depth calculations are carried out to reveal the origin of excellent NLO properties. These covalent crystals provide a new direction for the research of UV NLO crystals. |
| Databáze: | OpenAIRE |
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