Critical coupling control of a microresonator by laser amplitude modulation.
We present a laser amplitude modulation technique to actively stabilize the critical coupling of a microresonator by controlling the evanescent coupling gap from an optical fiber taper. It is a form of nulled lock-in detection, which decouples laser intensity fluctuations from the critical coupling measurement. We achieved a stabilization bandwidth of ∼ 20 Hz, with up to 5 orders of magnitude displacement noise suppression at 10 mHz, and an inferred gap stability of better than a picometer/√Hz.
Centre for Gravitational Physics, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200, Australia. jong.chow@anu.edu.au
Jong H
JH
Chow
Michael A
MA
Taylor
Timothy T-Y
TT
Lam
Joachim
J
Knittel
Jye D
JD
Sawtell-Rickson
Daniel A
DA
Shaddock
Malcolm B
MB
Gray
David E
DE
McClelland
Warwick P
WP
Bowen
D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007834:Lasers; D008027:Light; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*