Patent ID: 7995208

Claim:
An optical assembly for use with a precision instrument, comprising: a. a frame assembly comprising: i. a top plate; a bottom plate; a first support member bonded between a first portion of the top plate and a first portion of the bottom plate; and a second support member bonded between a second portion of the top plate and a second portion of the bottom plate; ii. the top plate, bottom plate and support member materials being at least one of the same material or materials having substantially the same coefficient of thermal expansion and defining a frame interior space; b. a beamsplitter inside the frame interior space and extending between the top plate and bottom plate, the beamsplitter having a first face and a second face; c. a mirror attached to the frame assembly, the mirror having a reflecting surface in a reflecting relation with the beamsplitter; d. a beamsplitter securing apparatus having spring arms and mounting buttons, the spring arms each having a free end and an end attached to one of either the top plate or the bottom plate and the mounting buttons each attached to one of either the top plate or bottom plate, the mounting buttons engaging the beamsplitter first face and the spring arm free end engaging the beamsplitter second face, wherein the optical assembly is substantially stable regarding the reflective relationship between the mirror and the beamsplitter and the beamsplitter first and second face having limited exposure to bending and warping.