A Fabry Perot resonator spacer is provided. The Fabry Perot resonator spaced includes a tetrahedral body, the tetrahedral body being made of a material having a Poisson ratio and defining a plurality of triangular faces, a plurality of edges, and a plurality of comers, wherein each one of the plurality of corners is truncated to form a mounting surface in a mounting plane. The spacer further includes a first mirror channel configured to receive a first optical element, a second mirror channel configured to receive a second optical element, and an optical cavity extending linearly through the tetrahedral body between the first mirror channel and the second mirror channel.