Experimental determination of the nonlinear refractive index in an operating Cr:forsterite femtosecond laser

B. Chassagne , A. Ivanov (1) , J. Oberle (1) , Gediminas Jonusauskas (1) , C. Rulliere (1)

1 CPMOH - Centre de physique moléculaire optique et hertzienne

The characteristics of a femtosecond forsterite Kerr-lens mode-locked laser pumped synchronously by an Nd:YAG laser are reported. Transform-limited femtosecond pulses of 60-fs (FWHM) duration with average TEM00 output powers of 200 mW at 1.25 μm were generated. Experimental studies of power stability and self-starting regime are described and a new experimental method to determine the nonlinear refractive index of the chromium-doped forsterite crystal (which is either the laser rod) is reported. We infer a value of 6 × 10−16 cm2/W at 1.25 μm, making possible Kerr-lens mode-locking.

Domaines: Physique [physics]; Optique [physics.optics]

B. Chassagne, A. Ivanov, J. Oberle, Gediminas Jonusauskas, C. Rulliere. Experimental determination of the nonlinear refractive index in an operating Cr:forsterite femtosecond laser. Optics Communications, 1997, 141 (1-2), pp.69-74. ⟨10.1016/S0030-4018(97)00213-7⟩. ⟨hal-01550178⟩