2001/04/01 by C. Svelto, F. Ferrario, Fabio Ferrario +5 · 1 citation
Engineering · Physics and Astronomy · #Solid State Laser Technologies #Advanced Fiber Laser Technologies #Photorefractive and Nonlinear Optics
paper · doi:10.1109/3.914398
The second harmonic output at 770.1 nm of a novel and compact Er-Yb:glass laser was frequency stabilized against the sub-Doppler linewidth of a crossover line in the /sup 39/K 4S/sub 1/2/-4P/sub 1/2/ transition as obtained by saturation spectroscopy. Efficient frequency doubling, with a conversion efficiency of /spl sim/220% W/sup -1/, and with second harmonic power in excess of 15 /spl mu/W, was achieved in a waveguide made in a periodically poled lithium niobate crystal. As measured through the analysis of the closed-loop error signal, a laser frequency instability of /spl sim/200 Hz was obtained; the Allan standard deviation of the frequency samples was below 4/spl times/10/sup -12/ for integration times /spl tau/ between 100 ms and 100 s, and reached a lowest floor level of 8/spl times/10/sup -13/ for 20 s/spl les//spl tau//spl les/100 s. The measured frequency noise spectral density was in good agreement with the analysis performed in the time domain. Compared to previously published data for stabilized solid-state laser sources in this wavelength region, these results represent a significant improvement in the frequency stability.