Optical interference phase control method with single photodetector for interference lithography.

Abstract

This study designs an optical phase control method for interference lithography system accompanied with severe disturbance. The system, which is designed based on the exponential reaching law of sliding mode control(SMCE), could adjust the interference phase with single photodetector. The model of system is derived and then the stability is proved through Lyapunov theorem. This paper also analyzes the behavior of the system under different reference voltages of photodetector. Both theoretical analysis and simulation experiment results suggest that this method can non-periodically achieve interference phase control with single photodetector by the switching module. Finally, the experimental device is set up, and the superiority of the SMCE method in transient response time and disturbance-resisting ability is demonstrated compared with the proportional-integral-derivative(PID) method.