Experimental results on gas-lens effects in (He-Ne)/CH/sub 4/ lasers ( lambda =3.39 mu m)

Design criteria have been established allowing the cancellation of spurious frequency offsets induced by gas-lens effects in He-Ne stabilized by saturated absorption in an intracavity absorber cell. They have been checked experimentally using a specially designed laser which was compared by beat-frequency measurements to the BIPM reference lasers. Good agreement is generally found between theory and experiment in spite of unexplained effects at low modulation amplitudes. Also observed in this special laser is the output effect, i.e the frequency change which occurs when the photodetector used for servocontrol is at one end or the other of the resonator.<
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