A liquid crystal on substrate (LCOS) assembly may include an LCOS carrier. The LCOS assembly may include at least one thick layer on the LCOS carrier and associated with a threshold thickness. The threshold thickness may be at least 5 micrometers. The LCOS assembly may include a switching engine on the at least one thick layer. The switching engine may include an LCOS die and an LCOS cover glass to enclose an LCOS liquid. The LCOS assembly may be associated with a thermal sensitivity of less than 0.5 millidegrees of curvature per degree Celsius for a particular temperature range.