In accordance with the invention, a mode-locked laser comprises an optical
gain medium disposed within an optical cavity formed by a first reflector
and a wavelength selective second reflector to achieve mode-locking
operation. Advantageously, the wavelength reflective reflector is a
two-dimensional subwavelength resonant grating. The resulting laser is
compact, tunable, reliable and inexpensive. It provides high side mode
suppression and high output power.