A novel high-resolution and large-range diffractive wavefront sensor

Based on the Talbot self-imaging principle, a diffraction-based wavefront sensor, the Z-View (TM) wavefront sensor, has been developed at Ophthonix Inc. According to the Talbot effect, a periodic grating can be self-imaged at certain distances behind the grating, commonly known as Talbot distances, without the aid of any imaging device. The fidelity of the Talbot image to the grating pattern is affected by the wavefront aberration in the illumination beam. Therefore, the wavefront distortion can be retrieved through numerical analysis of the Talbot image. Unlike the well-known Shack-Hartmann wavefront sensor, where a group of pixels on the camera is responsible for only one wavefront data point, each camera pixel in the Z-View wavefront sensor has a corresponding wavefront data. The Z-View wavefront sensor measures the wavefront at 1024 x 1048 data points, and can achieve a dynamic range of wavefront curvature of 20 diopters. The Z-View wavefront sensor has been successfully used for wavefront sensing in ophthalmic aberrometry, adaptive optics, and lensometry at Ophthonix.