A numerical approach for designing multi-wavelength plate

Wave plates made of birefringent materials can only be used at certain single wavelength, since the phase retardation produced is approximately inverse proportional to the wavelength. In this article, we introduced a geometric numerical method to design multi-wavelength wave plates with the plot of the curves of kd0(λ) (k=1, 2,…), where d0(λ) is the thickness of the zero-order λ/4 waveplate. The two common cases in designing are discussed and simulated with quartz crystal as application examples. In the first case, the thickness is specified. A quartz plate with thickness of 1 mm is designed, which operates as λ/4 waveplate at 866 nm, as λ/2 waveplate at 777 nm, and as λ waveplate at 6…