Tir imaging lens, image capturing system having the same, and associated methods

Abstract

A method of manufacturing lenses includes creating a wafer-level master, overmolding the wafer-level master to form a daughter replica, casting a polymer lens shapes onto a wafer using the daughter replica, transferring the polymer lens shapes into the wafer, and singulating the wafer to create individual dies with a lens thereon. The wafer may be silicon, e.g., silicon having a resistivity between 0.1 and 100 Ωcm.

1 . An imaging lens for use with an operational waveband over any subset of 7.5-13.5 μm, the imaging lens comprising:
 a silicon element having an image side surface and an object side surface, at least one of the image side and object side surfaces being an optically powered surface with a lens having a surface finish with a roughness of less than 20 nm Ra. 
 
     
     
         2 . The imaging lens as claimed in  claim 1 , wherein the optically powered surface includes a blend region beyond a clear aperture of the lens, the blend region terminating at a flat region. 
     
     
         3 . The imaging lens as claimed in  claim 2 , wherein the flat region is higher than a lowest point of the lens. 
     
     
         4 . The imaging lens as claimed in  claim 3 , wherein the flat region is higher than a lowest point of the blend region. 
     
     
         5 . The imaging lens as claimed in  claim 1 , wherein the silicon element is non-circular. 
     
     
         6 . The imaging lens as claimed in  claim 5 , wherein the silicon element is polygonal. 
     
     
         7 . The imaging lens as claimed in  claim 1 , wherein the silicon element further includes die features on at least one of the image side and object side surfaces. 
     
     
         8 . The imaging lens as claimed in  claim 7 , wherein the die features include at least one of a die alignment mark, a wafer alignment mark, and a die identifier. 
     
     
         9 . The imaging lens as claimed in  claim 1 , further comprising:
 an optical element having an image side surface and an object side surface, at least one of the image side and object side surfaces being an optically powered surface.   
     
     
         10 . The imaging lens as claimed in  claim 9 , wherein the optical element made of silicon. 
     
     
         11 . The imaging lens as claimed in  claim 10 , wherein the optical element is non-circular. 
     
     
         12 . The imaging lens as claimed in  claim 1 , wherein the silicon element has a resistivity between 0.1 and 100 Ωcm. 
     
     
         13 . The imaging lens as claimed in  claim 12 , wherein the silicon element has a resistivity between 1 and 3.5 Ωcm. 
     
     
         14 . The imaging lens as claimed in  claim 12 , wherein the silicon element is n-type silicon. 
     
     
         15 . The imaging lens as claimed in  claim 1 , wherein the optically powered surface is aspheric. 
     
     
         16 .- 42 . (canceled) 
     
     
         43 . An imaging lens for use with an operational waveband over any subset of 7.5-13.5 μm, the imaging lens comprising:
 a silicon element having an image side surface and an object side surface, at least one of the image side and object side surfaces being an optically powered surface, the silicon element having a resistivity between 0.1 and 100 Ωcm. 
 
     
     
         44 . The imaging lens as claimed in  claim 43 , wherein the silicon element has a resistivity between 1 and 10 Ωcm. 
     
     
         45 . An imaging system for use with an operational waveband over any subset of 7.5-13.5 μm, the imaging system comprising:
 a sensor; and 
 a silicon element having an image side surface and an object side surface, at least one of the image side and object side surfaces being an optically powered surface, the silicon element having a resistivity between 0.1 and 100 Ωcm. 
 
     
     
         46 . The imaging system as claimed in  claim 45 , further comprising a non-silicon element having an image side surface and an object side surface, at least one of the image side and object side surfaces being an optically powered surface.