Patent ID: 7327471

Claim:
Laser frequency stabilizing apparatus for stabilizing the frequency of a laser based upon an initial beam generated by the laser, the apparatus comprising: a frequency changing actuator for changing the frequency of the laser in response to a laser frequency control signal; a beam splitter system for producing a first split beam and a second split beam from the initial laser beam; a first servo system incorporating— an input interface for receiving the first split beam as an input, a low finesse etalon (LFE) having a resonant frequency for generating an LFE response signal responsive to detuning between the first split beam input frequency and the LFE resonant frequency, and an output interface for outputting the LFE response signal as a first error signal; a second servo system incorporating— an input interface for receiving the second split beam as an input, a high finesse etalon (HFE) having a resonant frequency for generating an HFE response signal responsive to detuning between the second split beam input frequency and the HFE resonant frequency, an output interface for outputting the HFE response signal as a second error signal, and a detector for determining that the second error signal is valid and outputting an enable signal when the second error signal is valid; and a control system for receiving the first error signal, the second error signal, and the enable signal and for outputting a laser frequency control signal based upon the received signals; wherein the frequency changing actuator is responsive to the laser frequency control signal and operates to alter the frequency of the laser in a direction such that at least one of either the first error signal or the second error signal indicates that the detuning is decreasing, and wherein at least one of the first servo system and the second servo system includes functionality to utilize one of a PDH locking technique, a polarization locking technique, and a tilt locking technique to produce at least one of the first error signal and the second error signal.