Fiber-coupling-operated orthogonal-linear-polarization Nd:YAG microchip laser: photothermal beat-frequency stabilization and interferometric displacement measurement application

The Nd/sup 3+/:YAG microchip laser is operated at orthogonal-linear-polarized two frequencies (/spl lambda/=1.06 /spl mu/m). A low crosstalk of 10/sup -4/ is accomplished by means of the fiber-coupled laser diode pumping. The effect of another fiber-coupled laser diode irradiation on the beat frequency is investigated in terms of photothermally induced stress. The beat frequency of typically 100 MHz is stabilized within /spl plusmn/1 MHz by means of the photothermal feedback control of the cavity stress. The utility of the laser in heterodyne interferometric displacement measurement with a good linearity and high resolution is demonstrated.