To make it possible to simultaneously generate two laser beams varying in frequencies and to stabilize the frequencies by receiving the light rays which are branched by an optical element for branching and are passed through a frequency discriminating element and controlling a light source by photoelectrically converting these light rays.
The laser beam emitted from a temp. controlled laser diode 2 passes an acousto-optic modulation element 4, by which the laser beam is separated to transmitted light and diffracted light. The transmitted light and the reflected light are partly outputted outside as output light. The remaining laser beam transmits the gas cell of the frequency discriminating element 5 and is received and is photoelectrically converted by a photodiode 6. The electrical input to the acousto-optic modulation element 4 in an acousto-optic modulation element control circuit 12 is adequately subjected to shallow amplitude modulation by the output signal of a modulation signal generator 9. The prescribed component in the output signal from the photodiode 6 when the electric input is subjected to the amplitude modulation shallow is detected by a lock-in amplifier 10 and the implantation current to the laser photodiode 2 is controlled in such a manner that this component is made zero.
MOTOHASHI HIROAKI
TOMOSADA NOBUHIRO
KOYAMA KIYOAKI
ADACHI TOSHIO
TAMURA TETSUJI
OYA AKIRA
IWAOKA HIDETO
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