| 摘要 |
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. |
| 主权项 |
1. A dichroic beamsplitter comprising:
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, wherein the composite prism has: (i) a flat external light input surface that lies within a first plane; (ii) a flat external light incidence and exit surface that lies within a second plane that is perpendicular to the first plane; (iii) a flat external light output surface that lies within a third plane that is parallel to the second plane; (iv) a coated surface internal to the composite prism and comprising 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; and (v) a flat external reflective surface or a total internal reflection surface, wherein the combined surfaces of the composite prism define a first light path that, for received light of a first wavelength that is incident to the light input surface, reflects the first wavelength light from the external reflective or total internal reflection interface surface, directs the first wavelength light to the internal coated surface, and outputs the light of the first wavelength in a first direction along an emission path that exits the light incidence and exit surface, and wherein the combined surfaces of the composite prism further define a second light path that, for received light of a second wavelength longer than the first wavelength and traveling along the emission path in a second direction opposite the first direction, directs the second wavelength light to the coated surface, and to exit, at a normal, through the light output surface. |
