Design of Dual-Wavelength High Precision Achro-Matic Phase Retarder

Abstract

In order to meet the demand of precise measurement and applications, based on the total-reflection phase transformation theory of the phase retardation, the principle of phase retardation with oblique incident angle is expounded. Spectral characterization of the phase retardation varing with refractive index is analyzed to high precision achromatic phase retarder to oblique incidence aided design. The result indicates that there is a maximum to dispersion curve of achromatic phase retarder with oblique incident in the center of the design refractive index department. The phase-delay drops on both sides to the center of the refractive index and can pass through a definite retardance value twice at two specified wavelength values. Accordingly, based on the detailed design of Fresnel rhomb, The new achromatic retarder with the specific incident angle and high precision is designed by choosing suitable meterial .It is shown at the achromatic property curve within the range of 500 nm to 1150 nm theoretically that the maximum deviation of the retardance from 90° is 0.006°, whereas at λR1R=532 nm and λR2R=1064 nm the retardance is approximately 90°±0.001°. and the corresponding calculation to the size of the devices indicates that the size of the devices for the same aperture will decrease for higher refractive index values.So optical materials with higher refractive indices are more convenient for this type of oblique incidence retarder .