Advanced weapon sighting systems fabricated with FemtoWrite and FemtoEtch processes

The Army has a need for better weapon sight reticles. Currently, weapon sight reticles are fabricated only on flat glass surfaces. These flat surfaces produce unwanted retro-reflections. During Phase I Translume demonstrated a femtosecond-laser based process to fabricate subsurface reticles in the bulk of flat or curved glass substrates. Subsurface reticles have much lower retroreflection than traditional reticles. Numerous prototypes were produced. We showed that we could locally change the index of refraction of the glass, thus creating features that can guide, or diffract light propagating through the glass. We also created scattering features that block or diffract light. The intensity of the scattering can be controlled over a large dynamic range. During Phase II we will employ these manufacturing processes to fabricate low reflectivity, high contrast, aberration-corrected, embedded reticles for the Leupold Mark 4 3.5-10x40mm Rifle Scope, which is used on the M110 7.62mm Semi-Automatic Sniper System (SASS). We will fabricate reticles embedded in flat substrates as well as in curved substrates. These reticles will be extensively tested. Their optical performances will be characterized and they will be compared to the present Leupold design. Pyrotechnic testing will be conducted.