Ring picosecond optical parametric oscillator pumped synchronously, intracavity, by a mode-locked Nd:YVO4 laser

The motivation of this work is the development of a laser sensor and gyroscope based on short pulse solid state ring laser. In comparison with regular ring laser containing the gain medium and saturable absorber where counterpropagating pulses overlap, a ring synchronously pumped optical parametric oscillator (OPO) where the pulse crossing point is controlled externally by the arrival time of the pump pulses is the ideal source for short pulse laser sensor. The optimum configuration is OPO synchronously pumped inside the resonator of mode-locked solid state laser. The operation of a picosecond synchronously intracavity pumped optical parametric oscillator (OPO) is reported. A magnesium doped lithium niobate crystal (MgO:PPLN), periodically poled, is used as the optical parametric oscillator crystal coupling the pump and the resonant signal cavities. The active medium of the passively mode-locked pump cavity is a diode pumped Nd:YVO4 crystal. Continuous mode-locked operation was achieved, tunable from 1531 to 1554 rim by adjusting the OPO crystal temperature from 31 to 56 degrees C. The spectral width of the generated radiation was 2 nm.