http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Free Spectral Range Measurement of Fabry-Perot Cavity using Frequency Modulation
Masato Aketagawa,Takuya Yashiki,Shohei Kimura,Tuan Quoc Banh 한국정밀공학회 2010 International Journal of Precision Engineering and Vol. No.
In this paper, we propose a novel method to measure the free spectral range (FSR) of a Fabry-Perot cavity (FPC)using single-frequency modulation (FM) with one electric optical modulator (EOM) and the null method. A laser beam modulated by the EOM, to which a cosine-wave signal is supplied from a radio frequency (RF) oscillator, is incident on the FPC. The transmission light from the FPC is observed and converted to an RF signal by a highspeed photodetector, and the RF signal is synchronously demodulated with a lock-in amplifier (LIA) by referring to the oscillator. We theoretically and experimentally demonstrate that the LIA signal become null with a steep slope, when the modulation frequency equals the FSR under the condition that the carrier frequency is slightly detuned from the resonance of the FPC. The experimental results show that the proposed method has the capability to determine the FSR by the null method with a small measurement uncertainty.