“…7−10 Generally, after the precipitation of crystalline phases, enhanced properties (e.g., strength and toughness) and/or new functionalities (e.g., second order nonlinear optical properties and linear or circular optical anisotropies) can be obtained in comparison to the parent glasses. 5,10−12 It has been demonstrated by Komatsu et al, 10,13 Hirao et al, 14 Miura et al, 15 Honma et al, 16 Qiu et al, 2,17,18 Jain et al, 19 Sigaev et al, 20,21 and Poumellec et al 22 that it is possible to induce crystallization in glasses with various lasers, such as continuous wave (CW) laser, 23 long laser pulses (e.g., nanosecond (ns) laser), 20 and ultrashort laser pulses (e.g., fs laser). 5,24 In comparison with CW lasers or ns lasers, the light intensity of focused femtosecond (fs) lasers may be as high as several TW/cm 2 .…”