Faxiang Zhang

Aug 14, 2023 | mdpi.com | Zhen Zhao |Shijie Zhang |Faxiang Zhang |Zhenhui Duan

3. Results and DiscussionThe reflected spectrums of the F–P sensors were observed when the expender with the sensors was mounted before the operation, as shown in Figure 5. The free spectral range (FSR), which is the distance between two adjacent wavelengths, was 3.9 nm for sensor1 and 3.85 nm for sensor2 at 1550 nm.