Increase of dynamic range of a Shack-Hartmann sensor by shifting detector plane

Weon-Woong Lee; Jun Ho Lee; Chang Kwon Hwangbo

doi:10.1117/12.571615

23 December 2004 Increase of dynamic range of a Shack-Hartmann sensor by shifting detector plane

Weon-Woong Lee, Jun Ho Lee, Chang Kwon Hwangbo

Proceedings Volume 5639, Adaptive Optics and Applications III; (2004) https://doi.org/10.1117/12.571615
Event: Photonics Asia, 2004, Beijing, China

Abstract

The Shack-Hartmann or Hartmann-Shack wavefront sensors are particular forms of the Hartmann sensor and are the most commonly used in adaptive optics. The traditional Hartmann screen in the pupil is replaced by an array of small lenslets at a conjugate to an image of the pupil or deformable mirror. Each lenslet forms an independent image of the incoming wavefront. Shifts in the positions of these images can be shown by simple geometric optics to be proportional to the mean wavefront gradient over each lenslet. The measurement range or dynamic range of a conventional Shack-Hartmann sensor is normally limited by the sub-aperture size of the detector plane, in which each spot should remain. In order to overcome this restriction, several methods, such as modified unwrapped algorithm or a spatial-light modulator as a shutter, have been proposed. We first simulated the image forming of a conventional Shack-Hartmann wavefront sensor for highly aberrated spherical aberrations through computer simulation, which confirmed that the well-known effect that high aberration shifts the spots outside its conventionally detectable area. We first develop a computer program that simulates Shack-Hartmann’s image forming and we show that simple defocusing the CCD plane can allocate the out-boundary spots to initial or reference positions, which results in the increase of the dynamic range of the Shack-Hartmann sensor.

Citation Download Citation

Weon-Woong Lee, Jun Ho Lee, and Chang Kwon Hwangbo "Increase of dynamic range of a Shack-Hartmann sensor by shifting detector plane", Proc. SPIE 5639, Adaptive Optics and Applications III, (23 December 2004); https://doi.org/10.1117/12.571615

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available