A novel method to measure the effective cavity length of distributed Bragg reflector (DBR) fiber laser with fiber Bragg grating (FBG) Fabry-Perot cavity as the resonator is proposed. The effective cavity length of DBR fiber laser is accurately measured by measuring the frequency spacing of two adjacent longitudinal modes in the cavity without the precise physical length of FBGs. The measuring accuracy as high as 10<sup>-5</sup> mm can be obtained by setting the resolution bandwidth of the spectrum analyzer.
© 2010 Chinese Optics Letters
Qing Ji, Xiurong Ma, Jing Sun, Hao Zhang, and Ying Yao, "Novel method for measurement of effective cavity length of DBR fiber," Chin. Opt. Lett. 8, 398-400 (2010)