  Uncoated corner cube retroreflectors (CCRs) operating via total internal
reflection (TIR) are less susceptible to internal heating than their
metal-coated analogs, lacking an absorber on the rear surface. Even so,
environments that induce differential heating within the CCR will result in
thermal lensing of the incident wavefront, introducing aberrations that will
generally reduce the central irradiance of the polarization-sensitive far-field
diffraction pattern (FFDP). In this paper, we characterize the sensitivity of
TIR CCRs to axial and radial thermal gradients. We present simulated FFDPs for
key input polarizations and incidence angles and provide a generalized analytic
model that approximates the behavior of the central irradiance as temperature
differences are introduced.
