Mirror mount

[1] In optics research, these can be quite sophisticated devices, due to the need to be able to tip and tilt the mirror by controlled amounts, while still holding it in a precise position when it is not being adjusted.

Adjustment screws drive the front plate about the axes of rotation in the pitch (vertical) and yaw (horizontal) directions.

In more expensive mounts, the flat surface (and perhaps the hole and v-groove too) may be made out of a much harder material (often sapphire), set into the frame.

This leads to precise movement of the frame when the micrometers or screws are turned, without unnecessary wobble or friction.

The screws can be driven by a motor under computer control to make this seem to the operator like simple rotation about a virtual pivot point in the center of the mirror surface.

The translation can instead be eliminated mechanically by using a gimbal mount, which uses two rings that each pivot about a line running through the center of the mirror.

The frames are ideally made of a light material, to make the resonant frequency of the structure high.

A shock can cause the mount to move away from the ball bearings, but because there are only 6, hard contacts, the mirror will return to the original position, preserving the alignment.

Stress from mounting can introduce aberration in the light reflected from a mirror, or photoelasticity inside a lens.

Critical phase matched crystals can be aligned and tuned precisely with a standard mirror mount.