Patent ID: 8147669

Claim:
A process for fabricating a reflective optical system, comprising: (a) providing at least a first mandrel and a second mandrel, each mandrel having an axis of elongation and having at one end thereof a negative end surface defining in negative shape a reflective surface; (b) providing an intermediate mandrel disposed between the first and second mandrels and extending between the ends thereof having said negative surfaces; (c) rigidly and releasably attaching the first mandrel and the second mandrel to each other, thereby forming a mandrel assembly, the axes of said at least first and second mandrels being non-coincident; (d) positioning the mandrel assembly in an electroforming bath and performing an electroforming operation for a predetermined period, thereby forming the optical system on the mandrel assembly; and (e) separating the mandrel assembly from the optical system, the optical system thereby having at least first and second elongate hollow sections, wherein each hollow section has an axis corresponding to the axis of elongation of a respective mandrel; wherein each hollow section has a first end, at which a reflective surface corresponding to the negative end surface of a respective mandrel is disposed, and a second end, the second ends being open; and wherein the axes of said at least first and second hollow section are oriented whereby an optical path is defined between said second ends via reflections at said reflective surfaces; and whereby said optical system has an off-axis configuration and whereby said optical system includes an intermediate section extending between said first and second hollow sections and providing an optical path between said first and second reflective surfaces.