Measurement of optical magnitude response based on double-sideband modulation

A novel approach to perform high-resolution optical magnitude response measurements, using optical double-sideband (ODSB) modulation, is proposed and experimentally demonstrated. As compared with a conventional optical single-sideband modulation-based optical magnitude response measurement, the proposed method based on ODSB modulation features not only simple configuration and doubled measurement range, but also immunity to modulation nonlinearity. A proof-of-concept experiment is carried out. The magnitude response of a fiber Bragg grating (FBG), in the range of 40 GHz, was measured with a resolution of 10 MHz, by using a 20 GHz microwave signal source.