Efficient, all-solid-state, Raman laser in the yellow, orange and red

We report efficient operation of a KGd(WO4)(2) Raman laser pumped by a small, 1 W, 532 nm laser module. By changing the output coupler and Raman crystal orientation, more than 8 wavelengths in the yellow-to-red spectral region were generated including 555 nm, 559 nm, 579 nm, 589 nm, 606 nm, 622 nm, 636 nm and 658 nm, ie., the first 4 Stokes orders on the two orthogonal high-gain Raman shifts of KGd(WO4)(2). We have also demonstrated spectrally pure output ( typically > 90% pure) for selected Stokes order with output power up to 400 mW. High slope efficiency ( up to 68%) and high beam quality (M-2 similar to 1.5) of Stokes output are obtained even at the highest pump power. (C) 2004 Optical Society of America.