Wavelenght selectable laser with inherent wavelenght and single-mode stability

摘要

A single-mode stabilized laser comprises a laser cavity having a round trip time tau r and a linewidth enhancement parameter alpha ; and a frequency routing device formed in the laser cavity comprising controllable frequency selective pathways such that selective gating of the frequency selective pathways causes selected lasing frequencies to be supported in the laser cavity separated by a frequency spacing DELTA FC, DELTA FC = 1/ tau r. The frequency routing device has an optical grating having unequal length waveguides to form paths. The optical grating has arms, a time delay tau f between the longest path and the shortest path, and a grating bandwidth DELTA FF, DELTA FF = 1/ tau f, at least one of (1) alpha and (2) tau r and tau f having sufficient value to stabilize the laser in single-mode operation. A method of turning on a laser having a waveguide grating to a stable operating condition comprises the steps of applying an initial current to a first amplifier and maintaining a second amplifier off; allowing the laser to reach thermal equilibrium; applying an operating current to the second amplifier; and applying another operating current to the first amplifier to stably operate the laser. <IMAGE>