Extended source wavefront sensor through optical correlation with a change in centroid position of light corresponding to a magnitude of tip/tilt aberration of optical jitter

摘要

An atmospheric aberration sensor that uses two optically correlated images of a scene and the Fourier transform capabilities of a lens or other focusing element. The sensor receives light via an f-number matching element from a scene or from an external optical system and transmits it through a focusing optical element to an updateable display element such as a spatial light modulator or micro mirror array, which modulates the real time image from the focusing element with previous template image of the same extended scene. The modulated image is focused onto an autocorrelation detection sensor, which detects a change in centroid position corresponding to a change of the tip/tilt in the optical path. This peak shift is detected by centroid detection and corresponds to the magnitude of global wavefront tip/tilt. With a lenslet array and detector array, the system can also measure local tip/tilt and higher order aberrations.

主权项

1. A wavefront sensing system for estimating tip-tilt or higher order wavefront aberrations in a wavefront of light passing through any aberration medium or aberrations induced from mechanical jitter in an optical system by autocorrellating a reference image of the scene and a real-time image of the scene, the system comprising:
an f-number matching element arranged for receiving the light from a scene or external optical imaging element; an updateable imaging sensor for capturing the reference image; an updateable display element; a beam splitter arranged to transmit a first portion of the light to the updateable imaging sensor and a remaining portion of the light to the updateable display element; the updateable display element arranged to have the reference image applied thereto for a predetermined period of time; a focusing optical element; and an autocorrelation detection sensor arranged in the focal plane of the focusing optical element, wherein in operation, light from a extended source scene is passed to the updateable display element where it is focused onto the autocorrelation detection sensor from a focusing optical element forming thereon an autocorrelation of the scene information passing through the updateable display element with the information from a template image acquired from the extended scene such that a change in a centroid position of the light on the autocorrelation detection sensor corresponds to a magnitude of tip/tilt aberration in the aberrating medium and/or magnitude of optical jitter.