High Resolution Fiber Optic Spectrometer System

A high resolution fiber optic spectrometer system was set up, which consists of a tunable laser, a fiber optic power meter, GPIB-USB data acquisition cards, and a computer control platform. The wavelength absolute accuracy of the tunable laser (Santec TSL-550) is +/- 2.5pm, and the wavelength setting resolution can be 0.1pm, which makes the system features high resolution. However, the resolution of the laboratory fiber optic spectrometer (YOKOGAWA AQ6317C) can only be set to 20pm. The extinction ratio (ER), free spectral range (FSR) and the trough position of the spectrum of the microfiber knot resonator (MKR) is measured with our system and AQ6317C fiber optic spectrometer. The experimental results of the two methods show that the ER and FSR are offset by 0.675dB and 0.003nm, respectively, and the standard deviations are 0.17% and 0.43%, respectively. From the results, and the stability of MKR is considered, we conclude that the resolution of our system can be better than 1nm due to the resolution of the TSL-550 light source, and the overall standard deviation is also smaller, therefore, the repeatability and stability of our testing system are better than the AQ6317C fiber optic spectrometer, which can better meet the actual measurement requirements.