Cavity configuration for a Q-switched simultaneous dual-wavelength Nd:YAlO_3 laser with the characteristic of polarization-dependent emission cross section

By investigating the rate equations of Q-switched simultaneous dual-wavelength lasers and by using the polarization-dependent emission cross section of a Nd:YAlO3 laser crystal to balance the equivalent emission cross sections of the dual lasing wavelengths, we have developed a new resonator configuration by introducing a quarter-wave polarization rotator. The two wavelengths exhibit an equal net gain in the laser rod, and the optimal spatial and temporal overlap can be achieved easily for optimal sum-frequency mixing. This configuration has a cavity length that is shorter than in previously used configurations, so it is suitable for operation at high output power and with a high repetition rate with a short thermally determined focal length.