Krauss-Kodytek Laura, Ruppert Claudia, Betz Markus
Opt Express. 2021 Oct 11;29(21):34522-34530. doi: 10.1364/OE.433953.
We investigate the non-degenerate two-photon absorption coefficient β(ω, ω) as a function of the non-degeneracy parameter ω/ω for bulk GaAs and Si at a constant transition energy + =1.57eV. In both materials, the two-photon absorption strength increases with increasing ω/ω regardless of the direct and indirect character of the bandgap. The GaAs measurement data agrees well with corresponding theoretical predictions for direct semiconductors. The Si data reveals similar trends albeit with smaller overall absorption strength. In addition, different crystallographic orientations and polarization configurations are analyzed.
我们研究了在恒定跃迁能量 ħω₁ + ħω₂ = 1.57eV 时，块状砷化镓（GaAs）和硅（Si）的非简并双光子吸收系数β(ω₁, ω₂) 作为非简并参数ω₁/ω₂ 的函数。在这两种材料中，无论带隙是直接带隙还是间接带隙，双光子吸收强度都随着ω₁/ω₂ 的增加而增加。砷化镓的测量数据与直接半导体的相应理论预测吻合良好。硅的数据也显示出类似的趋势，尽管整体吸收强度较小。此外，还分析了不同的晶体取向和偏振配置。
