Abstract: An optical image splitter disposed in the path of image-bearing light along an optical axis has a coated dichroic surface disposed at an angle of 15 degrees or less relative to incident light along the optical axis. The coated dichroic surface has a number of layers of material, the of layers including layers having a first refractive index, nL, and layers having a second refractive index, nH, greater than the first refractive index. The coated surface transmits light of at least a first wavelength range to form a first image at an image plane and reflects light of a second wavelength range to form a second image at the image plane.

Abstract: A method for forming an optical element deposits a first thin film coating to form a first coated surface on a first transparent substrate that is substantially flat, wherein, for incident light at an angle of incidence exceeding 5 degrees, the first multilayer thin film coating transmits a first wavelength band and reflects a second wavelength band. The first coated surface has a first surface form, and further has a second surface opposite the first coated surface with a second surface form. The second surface of the first substrate bonds to a third surface of a second transparent substrate to form the optical element. The third surface has a third surface form prior to bonding and the first coated surface has a fourth surface form after bonding. The difference between the fourth and the third surface forms is less than the difference between the first and third surface forms.

Abstract: A dichroic beamsplitter has a composite prism that has at least first and second prism elements that are coupled together along facing surfaces, wherein the respective facing surfaces of the first and second prism elements are equidistant from each other. The composite prism has a first flat external surface that lies within a first plane, a second flat external surface that lies within a second plane that is perpendicular to the first plane, a third flat external surface that lies within a third plane that is parallel to the second plane, and a coated surface internal to the composite prism and having a multilayer thin-film dichroic beamsplitter coating, wherein the coated surface lies within a fourth plane that intersects at least one of the first, second, and third planes at an angle that is less than about 25 degrees.

Abstract: A method for forming an optical element deposits a first thin film coating to form a first coated surface on a first transparent substrate that is substantially flat, wherein, for incident light at an angle of incidence exceeding 5 degrees, the first multilayer thin film coating transmits a first wavelength band and reflects a second wavelength band. The first coated surface has a first surface form, and further has a second surface opposite the first coated surface with a second surface form. The second surface of the first substrate bonds to a third surface of a second transparent substrate to form the optical element. The third surface has a third surface form prior to bonding and the first coated surface has a fourth surface form after bonding. The difference between the fourth and the third surface forms is less than the difference between the first and third surface forms.

Abstract: An optical image splitter disposed in the path of image-bearing light along an optical axis has a coated dichroic surface disposed at an angle of 15 degrees or less relative to incident light along the optical axis. The coated dichroic surface has a number of layers of material, the of layers including layers having a first refractive index, nL, and layers having a second refractive index, nH, greater than the first refractive index. The coated surface transmits light of at least a first wavelength range to form a first image at an image plane and reflects light of a second wavelength range to form a second image at the image plane.

Abstract: A dichroic beamsplitter has a composite prism that has at least first and second prism elements that are coupled together along facing surfaces, wherein the respective facing surfaces of the first and second prism elements are equidistant from each other. The composite prism has a first flat external surface that lies within a first plane, a second flat external surface that lies within a second plane that is perpendicular to the first plane, a third flat external surface that lies within a third plane that is parallel to the second plane, and a coated surface internal to the composite prism and having a multilayer thin-film dichroic beamsplitter coating, wherein the coated surface lies within a fourth plane that intersects at least one of the first, second, and third planes at an angle that is less than about 25 degrees.