Apparatus for producing a hologram

Abstract

An apparatus for producing a hologram includes a collimation lens configured to receive incoherent light emitted from an object; a spatial light modulator (SLM) that includes at least one diffractive lens which is configured to receive the incoherent light from the collimation lens and split the incoherent light into two beams that interfere with each other; and a camera configured to record the interference pattern of the two beams to create a hologram, wherein a ratio between a distance from the SLM to the camera and a focal length of the diffractive lens is greater than 1.

1 . (canceled) 
     
     
         2 . A system configured to examine a sample by both regular microscopy and Fresnel Incoherent Correlation Holography (FINCH), the system comprising:
 a mirror slider configured to position a reflective mirror into a path of light emitted from an object when the system is set to perform regular microscopy, and to remove the reflective mirror from the path when the system is set for FINCH;   a beam splitter configured to receive the light emitted from the object and reflected off the reflective mirror when the system is set to perform regular microscopy;   an imaging camera configured to record an image formed at the system output;   a reflective spatial light modulator (SLM) configured to receive the light emitted from the object when the system is set for FINCH, and to split the light into two beams that interfere with each other; and   a holography camera configured to record the interference pattern of the interfering light beams to create a hologram,   wherein the SLM is configured at an angle with respect to the image slide.   
     
     
         3 . The system according to  claim 2 , wherein the SLM is transmissive in-line in the optical path with respect to the image slide. 
     
     
         4 . The system according to  claim 2 , wherein the SLM is configured at an angle of 45 degrees with respect to the image slide. 
     
     
         5 . The system according to  claim 2 , further comprising an output polarizer between the SLM and the holography camera such that the two beams pass through the output polarizer. 
     
     
         6 . The system according to  claim 2 , wherein the beam splitter is arranged to split the light reflected off the reflective mirror in to a first light beam directed to an imaging camera and a second light beam directed to a monocular viewing port. 
     
     
         7 . The system according to  claim 2 , further comprising a tube lens arranged between the reflective mirror and the beam splitter. 
     
     
         8 . The system according to  claim 2 , further comprising an input polarizer slider that is controllable to move an input polarizer into the path of light emitted from an object. 
     
     
         9 . The system according to  claim 8 , wherein the input polarizer is arranged in the path between the dichroic mirror and the SLM. 
     
     
         10 . The system according to  claim 9 , wherein when the system is set for FINCH the reflective mirror is not in the path and the input polarizer is in the path, and when the system is set to perform regular microscopy the reflective mirror is in the path and the input polarizer is not in the path. 
     
     
         11 . The system according to  claim 2 , wherein the system is configurable, by changing a position of the reflective mirror by manipulating the mirror slider, to compare FINCH to standard fluorescence microscopy on the same identical sample without change in position or focus. 
     
     
         12 . The system according to  claim 11 , wherein imaging of the sample using the SLM as a tube lens is performed by moving the input polarizer and the reflective mirror out of the path and displaying a diffractive lens pattern with a focal length equivalent to the distance between the SLM and the holographic camera. 
     
     
         13 . The system according to  claim 2 , wherein the SLM is configured to have a positive lens mask over the whole SLM and the two beams with two mutually orthogonal polarization components, one of which is parallel to the polarization of the SLM and the other which is orthogonal to it, so that the interference happens between the projections of each polarization component of the beams on the crossing angle between the two orthogonal polarizations. 
     
     
         14 . The system according to  claim 2 , wherein firmware of the SLM is modified to give a 27π phase shift over its range at a 45° angle and Fresnel patterns displayed on the SLM are adjusted for the 45° angle. 
     
     
         15 . The system according to  claim 14 , wherein an input polarizer and an output polarizer are rotated 45° along the optical axis for improved resolution, so that all pixels on the SLM are utilized to create two interfering wavefronts. 
     
     
         16 . An apparatus for producing a hologram, comprising:
 a tube lens configured to receive light emitted from an object;   a first mirror;   a second mirror;   a beam splitting cube configured to receive light emitted from the object via the tube lens and to split the light in two directions towards the first mirror and the second mirror;   a first lens positioned in the pathway between the beam splitting cube and the first mirror;   a second lens position in the pathway between the beam splitting cube and the second mirror; and   a hologram plane configured to receive light emitted from the beam splitting cube after it is reflected off the first mirror and the second mirror to produce a hologram, the beam splitting cube being disposed between the hologram plane and each of the first mirror and second mirror with respect to the light that is reflected by the beam splitting cube towards the hologram plane.