Fig. 1. Structure diagram of the fiber F-P tunable filter based on PZT

Fig. 2. Swept laser system. (a) Schematic diagram; (b) physical photograph

Fig. 3. Real-time signal of the swept laser displayed on oscilloscope. (a) Swept laser from output1 when the SOA1 is without on-off control; (b) swept laser from output2 when the SOA1 is with on-off control

Fig. 4. Spectrum range of the swept source observed on the optical spectrum analyzer. (a) Output spectrum of the ring cavity when the SOA1 is without on-off control; (b) output spectrum of the whole swept laser system when the SOA1 is with on-off control

Fig. 5. Measurement schemes of coherence length for swept laser. (a) Scheme based on adjustable MZI and oscilloscope; (b) scheme based on adjustable MZI and OCT imaging platform

Fig. 6. Test results of coherence length based on adjustable MZI and oscilloscope. (a) Interference fringe when the adjustable MZI is at near-zero optical path-length difference; (b) interference fringe when the optical path difference is equal to the coherence length

Fig. 7. Amplitude fall-off of the point spread function as a function of imaging depth

Fig. 8. Average output power of the swept laser as a function of SOA2 bias current