A silicone gel for LED encapsulation and other photonic applications has been released by NuSil Technology. The developmental product, Gel-9617-30, resists optical degradation when exposed to UV radiation or extreme temperatures. Its refractive index of 1.54 enhances optical device efficiency. The substance, which comes in 50-ml kits, is an effective medium for phosphor incorporation. It is designed to cure at room temperature but can be rapidly cured with heat where there is potential for substrate and lens delamination. The gel has been added to the company’s Lightspan line of materials.