Optimization of fluxes for Yb:YMgBO crystal growth and intense multi-wavelength emission characteristics in spectra and laser performances

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 9; no. 41; pp. 14766 - 14776
• Main Authors: Sun, Shijia, Li, Bingxuan, Lou, Fei, Shi, Xingjun, Chen, Weidong, Yuan, Feifei, Zhang, Lizhen, Lin, Zhoubin, Zhong, Degao, Huang, Yisheng, Teng, Bing
• Format: Journal Article
• Published: 28.10.2021
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d1tc03909a

Yb 3+ -doped YMgB 5 O 10 (Yb:YMB) crystals with better crystalline quality were grown successfully using the optimized flux of Li 2 O-B 2 O 3 -LiF instead of the traditional K 2 O 3 -MoO 3 flux by the top-seeded solution growth method. The systematic investigation of the crystal growth, structure characteristics, polarized absorption and emission spectra, fluorescence decay curve and laser properties of the Yb:YMB crystal was reported for the first time. The main spectroscopic and laser parameters, such as the absorption coefficients and cross-sections, energy level schema and barycenter plot, radiative and fluorescence lifetime, emission and gain cross-sections, minimum inversion fraction, pump saturation intensity and minimum absorbed pump intensity, have been calculated and analysed in detail. The broad absorption band (FWHM, 18.4 nm, E // Z ) at around 936 nm matches very well with the emission wavelength of InGaAs laser diodes. The intense spectra anisotropy and multi-wavelength emission characteristics make it possible to realize the multi-wavelength laser operation at about 1 μm. The dual-wavelength Yb:YMB laser working at 1036 and 1062 nm with a maximum output power of 3.02 W and a slope efficiency of 46.9% was achieved, which may be a potential light source for THz generation with a large frequency difference of 7.1 THz. The results reveal that Yb:YMB is a promising multi-wavelength laser crystal. Yb:YMB crystals were grown using the optimized Li 2 O-B 2 O 3 -LiF flux instead of the traditional K 2 O 3 -MoO 3 flux by the TSSG method. The demonstration of dual-wavelength laser operation reveals the potential in THz generation.