Misalignment characteristics of tunable PPLN mid-infrared optical parametric oscillator

The misalignment characteristics of PPLN optical parametric oscillator(OPO) have been experimentally studied. On the basis of PPLN mid-infrared output, the effects of PPLN shift and mirror tilt on misalignment characteristics have been studied in order to provide references for optimization and practical use. The results show that the misalignment characteristics of PPLN OPO are different from those of normal laser because of the small size and parametric oscillating characteristics of PPLN. The misalignment tolerance of PPLN OPO to crystal shift along x-axis is larger than that to y-axis shift; the misalignment tolerance to mirror tilt around y-axis is larger than that to mirror tilt around x-axis. The temperature and channel of PPLN almost have no effect on misalignment tolerances of PPL