Relating to chiral detection systems, various improvements are disclosed including an improved apparatus for detecting a chiral property of a sample. It has a rugged and stable optical rail that operates as a heat sink to the systems' elements and comprises a captive guide structure of heat conductive material having an elevated top platform and a dove tailed lip on the sides. The elevated top platform has a substantial width in comparison to a height of the elevated top platform. The apparatus further includes a wide base portion of heat conductive material supportive of the captive guide structure. The base has a width that is at least twice the width of the elevated top platform and a substantial thickness relative to the captive guide structure. Multiple system elements can be securely mounted on the captive guide structure with some elements being in thermal contact with the elevated top platform.