US 11,809,133 B2
Opto-mechanical system to remove zeroth order diffraction in phase-only spatial light modulator
Hongzhou Ma, Centreville, VA (US); and Jeffery S. Brooker, Manassas, VA (US)
Assigned to Thorlabs, Inc., Newton, NJ (US)
Filed by Thorlabs, Inc., Newton, NJ (US)
Filed on Jan. 19, 2022, as Appl. No. 17/578,961.
Claims priority of provisional application 63/138,967, filed on Jan. 19, 2021.
Prior Publication US 2022/0229398 A1, Jul. 21, 2022
Int. Cl. G02B 26/06 (2006.01); G03H 1/22 (2006.01); G03H 1/08 (2006.01)
CPC G03H 1/2294 (2013.01) [G03H 1/08 (2013.01); G03H 2222/12 (2013.01); G03H 2223/13 (2013.01); G03H 2223/19 (2013.01); G03H 2223/24 (2013.01); G03H 2225/32 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An optical image generation system comprising:
a spatial light modulator (SLM) configured to receive an input collimated laser beam and phase-modulate the wavefront of the laser beam;
one or more optical elements configured to project the modulated laser beam onto a focal plane;
a first mirror and a second mirror situated at the focal plane, an edge of the first mirror being adjacent to an edge of the second mirror, the first mirror being configured to reflect a first portion of the modulated laser beam in a first direction, and the second mirror being configured to reflect a second portion of the modulated laser beam in a second direction; and
a tube lens and an objective lens configured to project the first and second portions into a combined image;
wherein the center of the focal plane falls in a gap between the edge of the first mirror and the edge of the second mirror, such that the zeroth order diffraction of the laser beam by the SLM is removed;
wherein a computer-generated hologram (CGH) is applied to the SLM to form an optical phase mask; and
wherein the CGH is pre-compensated for shifts of image due to the first and second mirrors, wherein the pre-compensating comprises applying respective first and second affine transforms to the first and second portions, the first and second affine transforms being based on a width of the image and a width of the block or gap.