US 11,892,802 B2
Lensless holographic imaging system using holographic optical element
Yeh-Wei Yu, Taoyuan (TW); and Ching-Cherng Sun, Taoyuan (TW)
Assigned to NATIONAL CENTRAL UNIVERSITY, Taoyuan (TW)
Filed by NATIONAL CENTRAL UNIVERSITY, Taoyuan (TW)
Filed on Oct. 23, 2020, as Appl. No. 17/078,321.
Claims priority of provisional application 62/991,211, filed on Mar. 18, 2020.
Prior Publication US 2021/0294265 A1, Sep. 23, 2021
Int. Cl. G03H 1/04 (2006.01); G03H 1/16 (2006.01)
CPC G03H 1/0443 (2013.01) [G03H 1/16 (2013.01); G03H 2001/0447 (2013.01); G03H 2001/0452 (2013.01); G03H 2222/34 (2013.01); G03H 2222/45 (2013.01); G03H 2223/23 (2013.01); G03H 2223/24 (2013.01); G03H 2225/52 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A lensless holographic imaging system having a holographic optical element, comprising:
a partially coherent light source for outputting a light beam;
a light modulator which is a rotatable mirror for receiving the light beam and modulating the light beam into a plurality of reading lights and each one having a specific wavefront;
a multiplexed holographic optical element irradiated with each one of the reading lights such that a portion of the each one of reading lights undergoes diffraction in the multiplexed holographic optical element and exits the multiplexed holographic optical element as a system reference light while another portion of the each one of reading lights exits the multiplexed holographic optical element through a first surface thereof as an object-irradiating light, the object-irradiating light being projected to and reflected by an inspection plane of an object under inspection to form an object-diffracted light, the object-diffracted light entering the multiplexed holographic optical element through the first surface thereof, passing through the multiplexed holographic optical element, and exiting the multiplexed holographic optical element through a second surface thereof; and
an image capture device located at the second surface and configured to read interference signals generated by interference between the object-diffracted light and the beam of system reference light corresponding to each one of the reading lights;
wherein the multiplexed holographic optical elements are set through a recording process irradiated with at least one recording light and at least one of the plurality of reading lights such that the multiplexed holographic optical elements record a plurality of interference patterns.