[OPTICAL REVIEW Vol. 1, No. 1 (1994) 79-81]
Micromechanical Photonics: Microresonator Displacement Measurement by an Extremely-Short-Length External Cavity Laser Diode
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