Fig. 1. Theoretical model of three mirror cavity

Fig. 2. Theoretical model of laser feedback speckle interference

Fig. 3. Theoretical model of multiple laser feedback interference

Fig. 4. Waveform in time domain of laser feedback interference with one-order, two-order, three-order feedback light

Fig. 5. Schematic of the microchip crystal laser with external frequency-shifted feedback setup

Fig. 6. Schematic of the tunable free-space self-interference microresonator setup

Fig. 7. Measurement setup of the pulse wave transmitting time based on laser feedback interference

Fig. 8. Schematic of the multiple-longitudinal laser feedback angle- measurement setup

Fig. 9. Schematic of the cytometry flow laser feedback measurement set and hydrodynamic channel chip

Fig. 10. Schematic of laser feedback confocal tomography setup

Fig. 11. Schematic of the laser confocal feedback tomographic imaging setup and kin carcinoma bionic decomposition