Small-frequency-difference stabilization of laser diodes using /sup 12/C/sub 2/H/sub 2/ and /sup 13/C/sub 2/H/sub 2/ absorption lines for transmitter and local oscillator of optical heterodyne systems

Small-frequency-difference stabilization of distributed Bragg reflector (DBR) laser diodes has been demonstrated for the first time by using vibrational-rotational absorption of /sup 12/C/sub 2/H/sub 2/ and /sup 13/C/sub 2/H/sub 2/ molecules. Frequency stabilization of two DBR laser diodes has been carried out at a wavelength of about 1.536 mu m. The frequency difference between the two stabilized lasers was evaluated to be 9 GHz by the beat spectrum measurement. The experimental results suggest that such a pair of frequency-stabilized laser diodes with a small frequency difference could be used as the transmitter and local oscillator of optical heterodyne systems.<
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