We describe a compact, economic and versatile diode laser system based
on commercial laser diodes, optically stabilized by means of feedback
from a diffraction grating. We offer detailed information which shoul
d enable the reader to copy our set-up which uses only easily machined
mechanical parts. Our system offers single-mode operation with a Line
width of a few 100 kHz, continuous scans over 25 GHz, high chirp rates
(up to 9 GHz/ms) and FM-modulation up to the GHz range. We discuss ra
diofrequency phase-locking of two independent lasers systems, allowing
well controlled fast frequency switching which overcomes the limitati
ons imposed by acousto-optic modulators.