Video Series from Allvar

Deriving a Passive Athermalization Figure of Merit for Length Comparison

Infrared optic lens materials present a unique challenge to opto-mechanical design. In this video, we derive a Figure of Merit (FOM) that describes a commonly used passive solution to the infrared optic negative thermal focus shift problem. This FOM is used in subsequent videos to compare the performance of different optic housing materials.

Length Effects of Different Passive Athermalization Materials.

The choice of housing materials for athermalizing infrared optics can drastically change the length of the optic. This video uses a previously derived Figure of Merit (FOM) to estimate the length of a passively athermal housing based on housing material selection. A 40% reduction in length is realized by replacing Aluminum with ALLVAR Alloy 30 in the commonly used Aluminum-Delrin material pair.