Generation of multi-frequency radiation in pulsed microchip laser with Raman conversion

The generation process in an end-diode-pumped microchip Nd:YAG/Cr:YAG laser with intracavity Raman conversion in barium nitrate crystal and with additional intracavity nonlinear conversion by harmonic generation and sum-mixing was studied. The generation at fundamental (1064 nm) and Stokes (1197 nm) wavelengths in the near-infrared range and at three wavelengths (532.0, 598.7, and 563.4 nm) in the visible range has been obtained. The pulse energy in the visible range reached 0.2 – 0.4 μJ, which corresponds to an average power of several miliwatts at a pulse repetition rate of up to 17 kHz. The pulse widths were less than 1 ns.