Thermal Drift Estimator

Estimate angular drift of kinematic optic mounts from differential thermal expansion between mount body and adjustment screws.

Materials
Environment & Geometry

Reflective: beam deviation = 2× mount tilt

Differential Expansion
Differential CTE
|α_mount − α_screw|
6.3000ppm/°C
Differential expansion
Over 25.000 mm lever arm, ΔT = 5.0000 °C
0.78750µm
Angular Drift
Angular drift
For ΔT = 5.0000 °C
31.500µrad
Angular drift rate
Δα = differential CTE
6.3000µrad/°C
Beam Displacement at Target
Beam displacement at 1.0000 m
2× mount tilt (reflective optic)
63.000µm
Assessment
Significant drift — use matched CTE materials or active temperature stabilization.
Abridged Optics — Thermal Drift Estimator v1.0Assumes uniform temperature change and linear expansion. Real drift may differ due to thermal gradients, contact compliance, and mounting preload.

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.