Optical system for cell imaging

Abstract

A microscope system ( 10, 10′, 10″, 10 ′″) includes a laser ( 18 ) or light emitting diode ( 18 ′″) that generates source light having a non-uniform spatial distribution. An optical system includes an objective ( 40 ) defining a field of view, and an optical train ( 22, 22′, 22″, 22 ′″) configured to convert the source light into an enlarged-diameter collimated light, to spatially homogenize the enlarged-diameter collimated light, and to couple the homogenized enlarged-diameter collimated light into the objective to provide substantially uniform static illumination of the field of view. A camera system ( 56 ) is statically optically coupled by the objective with at least most of the field of view.

1 . An optical system for imaging a field of view, the optical system comprising:
 an optical train configured to adjust a non-uniform distribution of source light to generate light having an adjusted non-uniform spatial distribution; and   an objective configured to focus the light having the adjusted non-uniform spatial distribution, the focusing defining illumination light that substantially uniformly illuminates the field of view;   wherein the optical train comprises:
 a stationary beam homogenizer that adjusts the source light to generate the light having the adjusted non-uniform spatial distribution; and 
 one or more focusing elements that reduce a diameter of the light having the adjusted non-uniform spatial distribution to couple the light having the adjusted non-uniform spatial distribution into the objective. 
   
     
     
         2 . The optical system as set forth in  claim 1 , wherein the source light has a nonuniform Gaussian distribution, and the optical train generates the light having an adjusted non-uniform spatial distribution with reduced or eliminated Gaussian nonuniformity. 
     
     
         3 . The optical system as set forth in  claim 1 , wherein the source light has a nonuniform Lambertian distribution, and the optical train generates the light having an adjusted non-uniform spatial distribution with reduced or eliminated Lambertian nonuniformity. 
     
     
         4 . The optical system as set forth in  claim 1 , wherein the optical train comprises only stationary components that are not rotated, relatively oscillated, or relatively moved. 
     
     
         5 . The optical system as set forth in  claim 4 , wherein the optical train and the objective are arranged to be moved as a whole respective to a sample to scan the field of view respective to the sample. 
     
     
         6 . The optical system as set forth in  claim 1 , further comprising:
 a generally tubular sample holder defining an annular sample region coinciding with the field of view.   
     
     
         7 . The optical system as set forth in  claim 1 , further comprising:
 an imaging optical sub-system including said objective, the imaging optical sub-system configured to use said objective to acquire an image of the field of view illuminated by said illumination light.   
     
     
         8 . An optical system for imaging a field of view, the optical system comprising:
 an objective focused on a field of view;   an optical train generating and inputting illumination light into the objective, said illumination light cooperating with focusing performed by the objective to substantially uniformly illuminate the field of view wherein the optical train includes a beam homogenizer configured to reduce nonuniformity of source light; and   an imaging optical sub-system including said objective, the imaging optical sub-system configured to use the objective to acquire an image of the field of view substantially uniformly illuminated by the optical train.   
     
     
         9 . The optical system as set forth in  claim 8 , further comprising:
 a sample holder configured to (i) define an annular sample region coinciding with the field of view and (ii) rotate the annular sample region respective to the objective.   
     
     
         10 . An optical system for imaging a microscope field of view, the optical system comprising:
 an objective focused on the microscope field of view; and   an optical train including:
 a stationary collimator collimating source light into a collimated light beam having a non-uniform distribution with a highest intensity central beam region, 
 a beam homogenizer disposed after the stationary collimator in the optical train and configured to reduce non-uniformity of the non-uniform distribution of the collimated light beam by one of (i) a non-uniform absorption profile having highest absorption in a central region corresponding to the highest intensity central beam region and (ii) a refractive configuration that refracts light from the highest intensity central beam region into a lower intensity periphery of the light beam, and 
   a stationary beam reducer disposed after the beam homogenizer in the optical train and coupling the collimated light into the objective.   
     
     
         11 . The optical system of  claim 10 , wherein the optical train further comprises:
 a beam expander preceding the stationary collimator in the optical train, the beam expander receiving and expanding a laser beam to form the source light that is collimated by the stationary collimator.   
     
     
         12 . The optical system of  claim 11 , wherein the laser beam and the source light have a Gaussian distribution. 
     
     
         13 . The optical system of  claim 10 , wherein the beam homogenizer is configured to reduce non-uniformity of the non-uniform distribution of the collimated light beam by a non-uniform absorption profile having highest absorption is in a central region corresponding to the highest intensity central beam region. 
     
     
         14 . The optical system of  claim 10 , wherein the beam homogenizer is configured to reduce non-uniformity of the non-uniform distribution of the collimated light beam by a refractive configuration that refracts light from the highest intensity central beam region into a lower intensity periphery of the light beam. 
     
     
         15 . The optical system of  claim 14 , wherein the beam homogenizer comprises a lens pair configured to reduce non-uniformity of the non-uniform distribution of the collimated light beam by refracting light from the highest intensity central beam region into a lower intensity periphery of the light beam.