Fig. 1. Simulation of self-mixing interference signals under various feedback levels

Fig. 2. Structure diagram of TO packaged VCSEL with photodiode integrated

Fig. 3. Experimental device for displacement measurement of photodiode photocurrent and laser diode junction voltage

Fig. 4. Image of self-mixing interference signals of integrated photodiode photocurrent and laser diode junction voltage with low signal-to-noise ratio

Fig. 5. Comparison of signal-to-noise ratio of self-mixing interference signals under different bias current levels

Fig. 6. Comparison of self-mixing interference signals of integrated photodiode and laser diode junction voltage in displacement experiment. (a)2.5 μm; (b) 5.0 μm