“…For the KGW2 crystal (corresponding to E||N g ) with Raman shift of 768 cm −1 , the calculated wavelengths of the first, second, and third-order Stokes laser are 1158.9, 1272.1, and 1409.9 nm. By our calculation, the Kerr lens and thermal lens effects of these Raman crystals are negligible at a pumping energy of 120 mJ [33,34]. According to a cascaded SRS model, the threshold of SRS for Stokes laser oscillating is determined by pumping depletion, reflectivity of cavity mirrors, Raman gain coefficient, and the length of the Raman medium [35,36].…”