Dynamic range enhancement of the roll angle displacement measurement with birefringence using a polarization camera.

A roll angle displacement measurement technique with high resolution for large-range measurement is presented. The proposed technique is based on the birefringence effect and phase detection of polarization interferometry with a polarization camera. The phase difference variation between the s- and p-polarized light induced by a rolling birefringent crystal can be obtained by a polarization camera. The roll angle displacement of the birefringent crystal can be determined from the detected phase difference variation. Several experiments were performed to evaluate the feasibility and performance of the proposed technique. The experimental results demonstrate that the resolution of the system can reach 0.003° with a 10° measurement range. The nonlinear and periodic errors of the system are also analyzed.

Measurement of the refractive index of lenses from the maximum phase difference of the total internal reflection with a polarization camera.

The proposed total internal reflection (TIR)-based technique can be used for measuring the refractive index of lenses. Distribution of the phase difference between the s- and p-polarization states of the reflected light induced by TIR can be obtained by a polarization camera. The refractive index of the lens can be determined from the detected maximum phase difference, with the specific measurement equation. Only the maximum phase difference needs to be measured. Information about the incident angle, thickness of the lens, and the matching liquid is not needed. The experimental results demonstrate that the resolution of the system can reach 4.8×10-4RIU.