The proof mass blanking surface is centrally positioned within and normal to the light ray null intensity region to provide increased blanking of the light ray in response to transverse movement of the mass on the input axis.
Accelerometers are added to many devices, including (smart) watches, phones and vehicles of all kinds.
The range is widened by small temperature changes and vibrations, and by imperfections in the laser cavity.
Under acceleration, the proof mass displacement relative to the concave mirror changes the intensity of reflected light.
The SolsTiS accelerometer has a titanium-doped sapphire cavity that is shaped in a way to encourage a narrow line width and to rapidly dissipate waste heat.
Another laser pulse detects the interference patterns in the various atoms, which reflects the amount of acceleration.
Military-grade laser accelerometers, drift (accumulate errors at the rate of) kilometres a day.