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U.S. Department of Energy
Office of Scientific and Technical Information

Frequency stabilized laser

Patent ·
OSTI ID:5495934

A frequency stabilized laser comprising a resonator having a given optical output frequency, the resonator comprising a pair of opposing end mirrors which define a laser cavity having a length which varies with temperature, one of the mirrors being the output mirror and the other a moveable mirror, a cavity length-controlling transducer attached to the moveable mirror and having a predetermined travel limit, a frequency control servo loop including means providing frequency reference, means applying a sample of the output of the laser to the frequency reference means, the frequency reference means providing an optical error signal, means for converting the optical error signal to an electrical signal, a low pass filter having a cutoff frequency much lower than the resonant frequency of the transducer and attached mirror, means applying the electrical signal to the low pass filter, a drive amplifier receiving the output of the of the low pass filter and applying an amplified output to the transducer to vary the spacing between the mirrors in such a direction as to reduce the error signal toward zero, the frequency control servo loop including high and low limit sensor circuits both connected to the transducer, the low limit sensor circuit providing a first output signal when the transducer approaches the lower limit of its travel, and means connected to the low limit sensor to generate a positive voltage pulse in response to the first output signal, the high limit sensor circuit providing a second output signal when the transducer approaches the upper limit of its travel, and means connected to the high limit sensor to generate a negative voltage pulse in response to the second output signal, and means to apply the positive and negative voltage pulses to the input of the drive amplifier.

Assignee:
US Secretary of the Army, Washington, DC
Patent Number(s):
US 4592058
OSTI ID:
5495934
Country of Publication:
United States
Language:
English