Kinematic Mount Selection for Optical Scanning Assemblies
Kinematic mount selection for optical scanning assemblies isolates substrates from thermal and dynamic distortions while maintaining sub-microradian repeatability.
Athermalization
Meaning
Design techniques for maintaining the performance of an optical or mechanical system across a specified temperature range ensure stability despite environmental fluctuations. This athermalization process involves the selection of materials with compensating thermal expansion coefficients or the use of active feedback mechanisms. It stops being effective when temperature gradients across the assembly exceed the design limits for passive compensation.
Stabilization Method
Selection of materials for mounts and lenses allows for the cancellation of focal shifts. Passive athermalization relies on the mechanical housing expanding at a rate that offsets the change in refractive index of the glass. This approach reduces the complexity of the assembly by removing the need for motorized focus adjustment.
Production Readiness
Testing in environmental chambers verifies that the focus remains within the depth of field during thermal cycling. A system that fails this audit requires a redesign of the optomechanical spacers or a change in the housing material. The cost of calling readiness before verifying this stability is a high rate of field failures in varying climates.
Thermal Gradient
Performance degrades when the front and rear of a lens assembly experience different temperatures. Uneven heating prevents the linear compensation logic from functioning correctly. A well characterized boundary for this effect determines the maximum allowable heat soak for the device.