1. Study of femtosecond laser writing in the bulk of Nd3+, Y3+ co-doped CaF2 crystals
- Author
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Chengkun Lyu, B. Hari Babu, Xiaotao Hao, Matthieu Lancry, Bertrand Poumellec, and Thomas Billotte
- Subjects
Birefringence ,Materials science ,Doping ,Phase (waves) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,010309 optics ,symbols.namesake ,law ,0103 physical sciences ,Femtosecond ,symbols ,Irradiation ,Electrical and Electronic Engineering ,Atomic physics ,0210 nano-technology ,Raman spectroscopy ,Refractive index - Abstract
We reported on the femtosecond (fs) laser induced permanent refractive index changes, stress-induced birefringence, and micro-photoluminescence properties of Nd3+, Y3+ codoped CaF2 crystals. Permanent changes in the linear optical properties were studied for various pulse energies (0.01 - 5 µJ) at two different repetition rates (10 kHz and 500 kHz). Optimum quantitative phase changes are close to - 1.7π radians within an irradiated area, surrounded by positive phase changes due to the stress field that can reach + 0.7π. Provided that, we avoid heat-accumulation at 500 kHz, written laser lines offer higher linear birefringence on the order of λ/4 at 200 nm. From the spectroscopic point of view, we observed the Raman changes and micro-photoluminescence spectra of irradiated fs-laser Nd3+, Y3+ doped CaF2.
- Published
- 2018