Diffraction efficiency of the structured thin-films phase grating (STFPG) at the visible wavelength is analyzed by the rigorous coupled wave analysis (RCWA) method demonstrating that the TM polarization can be separated from the 0th transmitted order of the TE polarization by ±1st order diffraction. The far field diffraction pattern is simulated by the finite-difference time-domain (FDTD) method to show the polarization beam splitting effect of the STFPG at wavelength of 633nm. In the near field, polarization dependent Talbot effect of the STFPG is also elaborated. FDTD simulations reveal that the spatial distribution of the interference fringes forming the self-image can be shifted by a half of grating period by changing the incident wave polarization within a particular wavelength range.
There are several techniques to measure the precise structure parameters of human eye in vivo. The design methods and
match of ophthalmic lens should be developed to accompany with the rapidly growing vision demands. We present a
method to design custom aspherical RGP CL(rigid gas permeable contact lens) which corrects high-order aberration of
RGP lens and human eye. We did the design by optimizing the aberration of the model consisting of Liou’s model eye
and RGP CL, the aspherical surface was placed on the front surface and damped least-squares methods were used for the
optimization. The lens designed could be manufactured in normal conditions and the wavefront aberration was reduced
to get much better vision experience. It might be one important way of custom design and match of RGP CL.
The Liou's model eye is close to anatomical, biometric and optical realities, and is effective in predicting the optical
performance. An efficient approach for designing of ophthalmic lenses by regarding ophthalmic lens and Liou's model
eye as a single optical system, based on optimization of aspherical surface coefficients is presented. The wavefront
aberration and diopter are taken into consideration, the traditional damped least-squares methods are chosen with the
high order aspherical equations being used. The appearance of the lens designed is improved obviously than the spherical
ones and the fabricating is not complicated; the optical performances are controlled in an acceptable range. With the help
of the structure parameters of a single eye ball obtained, custom-design ophthalmic lens is workable which might be a
direction of lens design in the future.
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