ar X iv : p hy si cs / 0 51 11 62 v 1 1 8 N ov 2 00 5 Compact solid - state laser source for 1 S − 2 S spectroscopy in atomic hydrogen

We demonstrate a novel compact solid-state laser source for high-resolution two-photon spectroscopy of the 1S − 2S transition in atomic hydrogen. The source emits up to 20 mW at 243 nm and consists of a 972 nm diode laser, a tapered amplifier, and two doubling stages. The diode laser is actively stabilized to a high-finesse cavity. We compare the new source to the stable 486 nm dye laser used in previous experiments and record 1S − 2S spectra using both systems. With the solid-state laser system we demonstrate a resolution of the hydrogen spectrometer of 6× 10 which is promising for a number of high-precision measurements in hydrogen-like systems.