Hiroo UKITA and Yoshio SUZUKI

Nippon Telegraph and Telephone Corporation, NTT Interdisciplinary Research Laboratories, 3-9-11, Midori-cho, Musashino, Tokyo, 180 Japan

(Accepted August 15, 1994)

A composite cavity laser diode was used to monitor the displacement of the external cavity microresonator from the phase difference in the near field. The carrier-to-noise ratio was very high (more than 45 dB) because of the lack of mode hopping noise due to the extremely short (less than 3 ×3μm) external cavity length and strong optical feedback. The small distance (near field) allows a lensless system, making it easier to integrate on a gallium arsenide (GaAs) substrate.

Key words : composite cavity laser diode, phase difference, displacement measurement, near field, microresonator, micromechanical photonics, photomicrodynamics