Two compound parabolic concentrators are used to create a 180°-field-of-view spectral filter. The collection optics are reflective and are designed to collimate the light through a multilayer interference filter and then to refocus it onto an optical detector. Assuming unit reflectance and no loss through the optical filter, this device operates at the thermodynamic collection limit.
© 1981 Optical Society of America
R. B. Miles, S. G. Webb, and E. L. Griffith, "Hemispherical-field-of-view, nonimaging narrow-band spectral filter," Opt. Lett. 6, 616-618 (1981)