Abstract

The Diffuse Infrared Background Experiment is a ten-band filter photometer on the NASA Cosmic Background Explorer. The entire telescope will operate at 2 K. Extragalactic infrared radiation and diffuse galactic radiation in the 1–300-μm wavelength range will be measured. Polarization measurements will also be made for the 1–3.5-μm range. The Diffuse Infrared Background Experiment is a well-baffled unobscured off-axis Gregorian telescope with multiple stops to provide a high level of rejection of both scattered and diffracted radiation. Additional optics are used so that each of three detector assemblies and a tuning fork chopper share a pupil image. The optics consist of an off-axis parabolic mirror, three off-axis elliptical mirrors, a general asphere, a fold flat, and a reflective chopper mirror. A breadboard optics module was constructed and used as a test bed to determine optical alignment procedures for the flight unit, to measure cryo-induced misalignments of the optical system, and to measure cryo-induced misalignments due to cryogenic vibration. Methods used to assemble the breadboard optics module and results of the environmental testing are reported in this paper.

© 1985 Optical Society of America