Patent ID: 6845108
Filing Date: 2005-01-18
Classification: H01S

Abstract:
1. A tunable laser, comprising: a laser cavity enclosing a laser gain medium which produces an optical gain for laser oscillation within a laser gain spectral range; an optical modulator in said laser cavity responsive to a modulation control signal to modulate at least one of an amplitude and a phase of light in said laser cavity at a modulation frequency to lock optical modes of said laser cavity to produce laser pulses; a tunable optical bandpass filter in said laser cavity to selectively transmit light at a transmission wavelength, said optical bandpass filter tunable to vary said transmission wavelength in response to a filter control signal; and a wavelength control unit producing said filter control signal to tune said filter and coupled to receive a portion of a pulsed laser output from said laser cavity as an optical monitor beam and operable to determine a deviation of a laser wavelength of said optical monitor beam from a reference wavelength, said wavelength control unit operable to adjust said filter to reduce said deviation, wherein said wavelength control unit comprises: a wavelocker to receive said optical monitor beam and to determine said deviation, said wavelocker producing an output electronic signal indicative of said deviation; a wavelocker circuit coupled to receive said electronic signal and to produce an error signal; a filter control circuit producing said filter control signal to said filter; a laser wavelength identifier to produce a wavelength Signal to said filter control circuit to tune said filter; and a locking circuit coupled between said wavelocker circuit and said filter control circuit to feed said error signal to said filter control circuit to stabilize said laser wavelength after said filter is tuned to a selected laser wavelength by said laser wavelength identifier.