A compact, high-performance extended-cavity diode laser in the Littrow geom
etry 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 m
ay 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.