Optimization of second harmonic generation in a Yb:KGW femtosecond laser. (31st October 2018)

• Record Type: Journal Article
• Authors: Kim, Dong Joon; Park, Eun Ji; Lee, Byunghak; Chizhov, Sergey A.; Sall, Elena G.; Kim, Jun Wan; Kim, Guang Hoon; Kim, Ji Won
• Is Part Of: Japanese journal of applied physics. Volume 57:Number 12(2018)
• Publication Date: 2018-10-31
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.57.122702
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: Efficient second harmonic generation (SHG) of a Yb:KGW laser with the femtosecond (fs) pulsed output using lithium triborate (LiB3 O4, LBO) and barium borate (BaB2 O4, BBO) as nonlinear optical (NLO) crystals is reported. Numerical calculation for frequency conversion efficiency as a function of the waist beam size and NLO crystal length shows that efficient SHG of the fs laser beam could be achieved using a relatively short crystal length with a tightly focused beam. We have applied this numerical calculation to SHG of the mode-locked Yb:KGW laser with an 175 fs pulse width and an 11.5 nm linewidth at 1036 nm. Predicted values for the conversion efficiency and its output spectrum are in good agreement with experimental results. Prospects for improvements of the SHG conversion efficiency and, furthermore, sum frequency generation using fundamental and SHG beams will be discussed.