title: Characterization of optical resonators with an incoherent light.
abstract: A new and simple technique is proposed and demonstrated for measuring the free spectral range (FSR) and bandwidth of optical resonators. For a broadband light input the resonator output forms an incoherent frequency comb with the spacing and linewidth corresponding to the FSR and bandwidth of the resonator, respectively. Photodetection of the resonator output produces heterodyne beat signals between the comb lines, from which the above two parameters can be estimated by spectrum analysis. The proposed technique overcomes the difficulties of conventional methods base on frequency-swept lasers. As demonstrations, fiber-optic Fabry-Perot and ring resonators are successfully characterized with the bandwidths as small as 10 kHz.
authors: Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology 1-1-1 Umezono, Tsukuba, Ibaraki, 305-8568, Japan. h-tsuchida@aist.go.jp
authors: Hidemi
authors: H
authors: Tsuchida