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

Abstract

The Nd3+:YAG microchip laser is operated at orthogonal-linear-polarized two frequencies (λ = 1.06 μm). A low crosstalk of 10-4 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 ±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.