Abstract: A receiver for a lidar system. The receiver comprises a monolithic block of optically transmissive material, the block shaped to define a planar light receiving surface, a first reflective surface and a second reflective surface positioned adjacent to the light receiving surface. The surfaces are positioned such that light from a distant on-axis source passing through the light receiving surface passes through the block to the first reflective surface and is reflected thereby towards the second reflective surface and in turn reflected thereby to pass through a receiving aperture formed in the first reflective surface and to come to a focus at or after the receiving aperture.