Objective measurement and correction of optical systems using wavefront analysis

A system comprising:

• an energy source for generating a beam of radiation;
• optics disposed in the path of said beam for directing said beam through a focusing optical system having a rear portion thereof functioning as a diffuse reflector, wherein said beam is diffusely reflected back from said rear portion as a wavefront of radiation that passes through said focusing optical system to impinge on said optics, said optics projecting said wavefront in direct correspondence with said wavefront impinging on said optics;
• and
• a wavefront analyzer disposed in the path of said wavefront projecting from said optics for calculating distortions of the wavefront as an estimate of aberrations of said focusing optical system, said wavefront analyzer comprising
• a plate that is light impervious except for an array of light transmissive apertures that allow impinging light to pass therethrough, said plate disposed in the path of said wavefront wherein portions of said wavefront pass through said array of light transmissive apertures;
• a planar array of light-sensitive cells arranged parallel to and spaced apart from said plate by a selected distance, wherein each of said portions of said wavefront passing through one of said array of light transmissive apertures illuminates a geometric shape covering a unique plurality of cells from said planar array of cells;
• a processor coupled to said planar array of cells for calculating said distortions based on a centroid of each said geometric shape;
• and
• means for adjusting said selected distance between said plate and said planar array of cells.

A system comprising:

• an energy source for generating a beam of optical radiation;
• focusing optics disposed in the path of said beam for directing said beam through a focusing optical system having a rear portion thereof functioning as a diffuse reflector, wherein said beam is diffusely reflected back from said rear portion as a wavefront of radiation that passes through said focusing optical system to impinge on said optics, said optics projecting said wavefront in direct correspondence with said wavefront impinging on said optics, said focusing optics comprising
• a first lens maintained in a first fixed position in the path of said beam and said wavefront;
• a second lens maintained in a second fixed position in the path of said beam and said wavefront;
• and
• an arrangement of optical elements disposed between said first lens and said second lens in the path of said beam and said wavefront, said arrangement of optical elements being adjustable for changing the optical path length between said first lens and said second lens;
• and
• a wavefront analyzer disposed in the path of said wavefront projecting from said optics for calculating distortions of the wavefront as an estimate of aberrations of said focusing optical system, said wavefront analyzer comprising
• a two-dimensional array of spherical lenslets that defines a focal plane that is a focal length away from said two-dimensional array of spherical lenslets, said two-dimensional array of spherical lenslets disposed in the path of said wavefront wherein portions of said wavefront pass through said two-dimensional array of spherical lenslets;
• a planar array of light-sensitive cells arranged parallel to and spaced apart from said two-dimensional array of spherical lenslets by a selected distance independent of said focal length, wherein each of said portions of said wavefront passing through said two-dimensional array of spherical lenslets illuminates a geometric shape covering a unique plurality of cells from said planar array of cells;
• a processor coupled to said planar array of CCD cells for calculating said distortions based on a centroid of each said geometric shape;
• and
• means for adjusting said selected distance between said two dimensional array of spherical lenslets and said planar array of cells.

An optical wavefront sensor, comprising:

• a plate that is light impervious except for an array of light transmissive apertures that allow impinging light to pass therethrough, said plate disposed in the path of an optical wavefront wherein portions of said optical wavefront pass through said array of light transmissive apertures;
• a planar array of lightsensitive cells arranged parallel to and spaced apart from said plate by a selected distance, wherein each of said portions of said optical wavefront passing through one of said array of light transmissive apertures illuminates a geometric shape covering a unique plurality of cells from said planar array of cells;
• and
• means for adjusting said selected distance between said plate and said planar array of cells.

A method comprising the steps of:

• generating a beam of optical radiation;
• focusing said beam with focusing optics into an eye to image said beam as a focused spot forming a near-diffraction limited image at a back portion of the retina of said eye, wherein said beam is diffusely reflected back from the retina as a wavefront of radiation that passes through said eye;
• allowing said wavefront to impinge on said focusing optics;
• projecting, with said focusing optics, said wavefront in direct correspondence with said wavefront impinging on said focusing optics;
• calculating distortions associated with said wavefront projecting from said focusing optics using a wavefront analyzer disposed in the path of said wavefront projecting from said focusing optics, wherein said wavefront analyzer includes a plate that is light impervious except for an array of light transmissive apertures that allow impinging light to pass therethrough, said plate disposed in the path of said wavefront wherein portions of said wavefront pass through said array of light transmissive apertures, and a planar array of light-sensitive cells arranged parallel to and spaced apart from said plate by a selected distance, wherein each of said portions of said wavefront passing through one of said array of light transmissive apertures illuminates a geometric shape covering a unique plurality of cells from said planar array of cells;
• and
• adjusting said selected distance to adjust the gain of said wavefront analyzer.

A method comprising the steps of:

• generating a beam of optical radiation;
• focusing said beam with focusing optics into an eye to image said beam as a focused spot forming a near-diffraction limited image at a back portion of the retina of said eye, wherein said beam is diffusely reflected back from the retina as a wavefront of radiation that passes through said eye;
• allowing said wavefront to impinge on said focusing optics;
• projecting, with said focusing optics, said wavefront in direct correspondence with said wavefront impinging on said focusing optics;
• calculating distortions associated with said wavefront projecting from said focusing optics using a wavefront analyzer disposed in the path of said wavefront projecting from said focusing optics, wherein said wavefront analyzer includes a two-dimensional array of spherical lenslets that defines a focal plane that is a focal length away from said two-dimensional array of spherical lenslets, said two-dimensional array of spherical lenslets disposed in the path of said wavefront wherein portions of said wavefront pass through said two-dimensional array of spherical lenslets, and a planar array of lightsensitive cells arranged parallel to and spaced apart from said two-dimensional array of spherical lenslets by a selected distance not equal to said focal length, wherein each of said portions of said wavefront passing through said two-dimensional array of spherical lenslets illuminates a geometric shape covering a unique plurality of cells from said planar array of cells having an array of holes passing therethrough;
• and
• adjusting said selected distance to adjust the gain of said wavefront analyzer.