Scalable visible Nd:YAG pumped Raman laser source

Experimental and analytical studies of a 60 Hz, 0.45 W, 630 nm Raman laser source with a 12 ns pulse duration have demonstrated an overall electrical to optical efficiency of 0.12 percent. This is the first demonstration of a short pulse, high repetition rate red laser at such a high average output power without the need for a visible pump laser. Additional significance arises from the fact that simple extensions of the present work will produce many wavelengths in the visible and near infrared (IR) spectral region. A 1064 nm Nd:YAG pump laser operating at 60 Hz was used to pump a methane gas Raman laser operating at 1544 nm. This wavelength was mixed with the remaining 1064 nm laser output in noncritically phase matched lithium niobate to produce 630 nm radiation. The optical energy conversion efficiencies for the three steps were 1.4, 30, and 20 percent, respectively, for output energies of 86 mJ at 1064 nm, 15 mJ at 1544 nm, and 7.5 mJ at 630 nm. rms pulse amplitude variation measured 6 percent or less. A 10.7 million pulse life test was conducted, and the average output energy did not vary more than ±10 percent from its initial value.