Wide-Field-of-View Near-Eye Display with Dual-Channel Waveguide

We propose a wide-field-of-view near-eye display featuring a dual-channel waveguide with cholesteric liquid crystal gratings. Our dual-channel waveguide is capable of splitting the field of view through the orthogonal polarization division multiplexing. To explain its mechanism, a diagram of k-domain, which factors into both the waveguide size and the number of pupils, is depicted. Our results demonstrate that the diagonal field of view reaches up to 80°, eye relief is 10 mm, exit pupil is 4 × 3 mm2, and uniformity is 79%.

Scaling the Retinal Image of the Wide-Angle Eye Using the Nodal Point

Angles subtended at the second nodal point of the eye (NP2) are approximately the same as input visual angles over a very large angular range, despite the nodal point being a paraxial lens property. Raytracing using an average pseudophakic eye showed that the angular nodal point criterion was only valid up to about 10°, and that the linear relationship was due instead to the cornea and lens initially creating chief ray angles at the exit pupil that are about 0.83 times input values for this particular eye, and then by the retina curving around to meet the rays in a manner that compensates for increasing angle. This linear relationship is then also maintained when retinal intersections are calculated relative to other axial points, with angles rescaled approximately using the equation R/(R + delta), where delta is the axial distance from the center of a spherical retina of radius R. Angles at NP2 approximately match the input angles, but the terminology is misleading because this is not a paraxial property of the eye. Chief rays are used with finite raytracing to determine the actual behavior.

Exit Pupil Expansion Based on Polarization Volume Grating

In this paper, we demonstrate a waveguide display structure which can realize a large field of view on a two-dimensional plane and a larger exit pupil size at the same time. This waveguide structure has three polarization volume gratings as its coupling elements. We use Zemax to simulate the effect of monochromatic and full-color two-dimensional exit pupil expansion and actually prepared a monochromatic waveguide with a two-dimensional exit pupil expansion structure. For the red, green, and blue light beams, it can achieve a large diffraction angle and can achieve diffraction efficiency of more than 70%. The waveguide structure shown can have an angle of view of 35° in the horizontal direction and 20° in the vertical direction, and an exit pupil of 18 mm long and 17 mm wide was achieved at the same time. As measured, the overall optical efficiency was measured as high as 118.3 cd/m2 per lumen with a transparency of 72% for ambient light.

Information and Metrology-Driven Optimisation of Wavefront Error in Telescope-Detected Radiation

The paper presents a solution to an information and metrology problem concerning minimising the wave-front error of telescope-detected radiation. As an example, we used aberration computation and simulation describing the optical system of the space telescope installed in the Millimetron observatory. We show that many factors that affect a space telescope decrease the quality of the image obtained. It is necessary to eliminate the effects of the distortion-generating factors and reduce their contribution to the total wavefront error. As the dimensions of the collecting aperture in telescopes increase, the factors that distort the wavefront of the radiation detected by the telescope begin to significantly affect the quality of the image obtained. We consider the ways of decreasing the effects of the distortion-generating factors caused by aberrations in the optical system. One of the solutions to this problem is to select a rational configuration of the space telescope optical system. In order to minimise the aberration, we used the Zemax 13 Release 2 SP4 Premium software package to simulate the optical system, to analyse and optimise it so as to diminish the scattering spot in the exit pupil. We achieved this goal by decreasing the spherical aberration and ensuring a more uniform distribution of it over the field. We used the data obtained to estimate the admissible dimensions of the misalignment spot