On the CLEO Europe 2009 (which was already one month ago!), I presented our recent progresses in developing 589 nm laser for laser guide star adaptive optics. We had coherently beam combined two high power narrow linewidth Raman fiber amplifiers with an efficiency of 95%. After frequency doubling in an external resonant cavity, we have achieved 25 W 589 nm laser with a linewidth less than 2.3 MHz, which is limited by measurement resolution. I have put the slides online: 25 W CW Raman-fiber-amplifier-based 589 nm source for laser guide star.
The conference was intensive and very interesting for me. I noticed many talks and posters on yellow laser generation aiming at laser guide star application. Besides our works, most notable are optically pumped semiconductor lasers, long wavelength Yb fiber lasers, and Bismuth doped fiber lasers. Some new technologies may appear in the coming years, since so many researchers are looking at this direction.
I attended the talk by Prof. Joss Bland-Hawthorn on Astrophotonics. It appears that he had come to my blog and noticed my “concern“. He agreed that laser guide star is an important part of Astrophotonics. 🙂