On January 29, 2021, IRflex Corporation signed a Phase II contract with the Department of Defense after completion of the Phase I project of the same title to develop an anti-reflective surface for infrared Optical fiber Endfaces.
The objective of the project is to develop an anti-reflective surface for use on bare and connectorized infrared fiber optic cable assembly in the wavelength interests of 1.4 to 5 micron. In such region, optical materials with a large index of refraction are often used. According to the Fresnel equation, reflection loss increases significantly when the difference between the index of the exit medium and the index of the entrance medium is 1 or greater. In addition to the need for low reflectivity, anti-reflective surfaces must be tolerant to high optical power.
The project requests that the anti-reflective surface should be realizable on non-silica optical fiber including indium fluoride, chalcogenide, tellurite, and ZBLAN. Fiber optic cables should be designed to assemble with Subminiature Version A (SMA) 905 connectors and be compatible with short and mid-wave laser sources for the wavelength interest region of 1.5 to 5 micron. The fiber optic cable assembly must pass thermal, vibration, and humidity environmental testing. The end result of this project is an anti-reflective surface with an improved damage threshold for high power application that can be manufactured.
The project started on February 1, 2021 and will last for the next two years.