We proposed an all-fiber tunable distributed Bragg reflector (DBR) laser rangefinder, which realized high-accuracy measurement of the absolute distance in the range of 1.88 to 3.33 m based on the self-mixing effect. The theoretical analysis of the all-fiber tunable DBR laser shows that wavelength tuning range and frequency of the laser can influence the measurement range and resolution. In addition, the experimental results indicate that the influence factors of measurement accuracy and sensitivity in absolute distance measurement are modulation response linearity, experimental equipment, and circuit bandwidth, which is in good agreement with theory analysis. Moreover, increasing the linear wavelength tuning range of the tunable DBR laser is an essential method to improve the measurement accuracy and sensitivity of the absolute distance measurement system.
A method for the measurement of the absolute distance based on wavelength tuning technology of DBR fiber laser is presented. Experimental results show that the fringe number of the self-mixing signal and the target distance can reach a good linear relationship which agreed with the simulation results well. This paper demonstrate that DBR fiber laser present a powerful tool for the self-mixing technique and provide measurement of the distance up to 3.33 meters.
In this paper, we presented a waveform reconstruction method based on the self-mixing interference of DFB fiber laser by phase modulating technique, which is superior to the traditional vibration measurement system due to the wider measurement range and higher accuracy. In our sinusoidal phase modulation technology, the vibration information of the external target is extracted by the Fourier transformation method. For restoring the micro-vibration of the external target effectively with high precision, theoretical analysis and numerical simulations of phase modulation method based on the Distribution Feedback Bragg fiber laser are introduced in detail.