Abstract A frequency stabilized gas laser having a substantially unmodulated output beam includes, within the optical path of the optical cavity, an absorption cell having a gaseous absorption medium exhibiting the stark effect, the absorption characteristic of the cell being shifted in frequency so that the average Lamb dip frequency is coincident with the primary transition frequency of the laser gain medium, the shift being varied a small amount in an oscillatory fashion around the primary transition frequency so as to provide a dithered net optical output gain characteristic to the laser cavity. The resulting relative variation in optical cavity power extraction is used to adjust the position of one mirror, therefore the length of the cavity and the resonant frequency thereof.
The frequency stabilized laser according to claim 1 wherein said last named means comprises: means responsive to the output power coupled from said laser to develop a feedback voltage; a synchronous detector having a signal input and a reference input, said reference input responsive to said oscillator, said signal input responsive to said feedback voltage; and an electromechanical transducer disposed on said one mirror and connected to the output of said synchronous detector.
Claim 2
Dependent Claim
68 words
The frequency stabilized laser according to claim 1 wherein said absorption cell comprises a stark cell having a pair of electric field inducing plates, said plates being connected to the output of said oscillator and to a DC potential, whereby the instantaneous and average center frequency of said Lamb dip characteristic are controlled as a result of stark effect response to said oscillator and to said DC potential.