A simple external cavity diode laser at 635nm

A compact, high-performance extended-cavity diode laser in the Littrow geometry has been realized at 635 nm. We place an upper limit of 470 kHz on the laser linewidth and obtain an output power of more than 10 mW. The laser may be tuned continuously over 21.6 GHz and discontinuously from 630 to 637 nm. Spectroscopy of iodine has been performed and the laser stabilized to a molecular absorption feature.