Theoretical and experimental research on the polarization-coupled-input Raman oscillator.

We present a polarization-coupled-input Raman oscillator, which is pumped by a 532 nm Q-switched hybrid resonator Nd:YVO(4) slab second harmonic generation laser. By the polarization-coupled method, the dichroic mirror is avoided and more than 98% of the 532 nm pump energy can be coupled into the Raman oscillator. Theoretical calculations and the experimental results show that the second Stokes effect is dramatically suppressed. With this method, the pure 559 nm (P(532)/P(559)<0.7% and P(589)/P(559)<0.1%) laser output can be achieved.