A new method for phase-shifting moiré interferometry is proposed and studied experimentally. A nematic liquid crystal cell is employed as a phase modulator to realize the phase-shifting technique for the conventional moire interferometry. The phase retardation of the liquid crystal cell is calibrated by measuring transmitted light intensities. By letting one of coherent beams pass through a liquid crystal cell and controlling the phase retardation via suitable voltages across the cell, the phase map that provides quantitative data regarding the in-plane surface displacement can be created. The use of the liquid crystal phase modulator in the moiré optical arrangement has several advantages over alteqrnative methods.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics