We propose new solutions for expanding the linear signal range between the laser frequency deviation (or mirror position) and the voltage signal derived by the Pound-Drever-Hall (PDH) method for optical Fabry–Perot cavity resonance control. One solution is to perform not in-phase demodulation but near-Q-phase demodulation. Another solution is to take a suitable combination of signals demodulated by odd-harmonic modulation frequencies in the in phase. Although the PDH signal sensitivity will be diminished, the PDH signal linear range can be extended. From a practical standpoint, it is desirable that a sideband frequency for the PDH method is near the FP cavity resonance.
© 2010 Optical Society of America
Instrumentation, Measurement, and Metrology
Original Manuscript: May 27, 2010
Revised Manuscript: August 13, 2010
Manuscript Accepted: August 17, 2010
Published: September 21, 2010
Shinji Miyoki, Souich Telada, and Takashi Uchiyama, "Expansion of linear range of Pound-Drever-Hall signal," Appl. Opt. 49, 5217-5225 (2010)