more phosphor materials that are usually applied directly onto the led die conventional methods of applying the one or more phosphor materials include spray coating the phosphor materials in a concentrated viscous fluid medium for example liquid glue onto the surface of the led die through which the generated light must pass as the viscous fluid sets or cures the phosphor material becomes a part of the led package however dosage and uniformity of a sprayed on phosphor material is difficult to control further the phosphor material is disposed in close proximity to the led die and subjected to thermal cycling which degrades the phosphor material over time reducing light output and changing color output optical components such as reflectors and lenses are used to shape the radiation pattern or beam pattern several optical components are often used to achieve a desired pattern for example a batwing beam pattern a lens may be made of plastic epoxy or silicone and is attached to the package substrate by gluing its edge onto the package substrate usually the lens is manufactured separately from the led die and is available in specific sizes and shapes conventional batwing optical emitters use two lenses to achieve the batwing pattern a first lens or primary optics is a transparent lens attached directly or formed directly on the led die the first lens is usually a semi ellipsoid and functions primarily to extract as much light as possible from the led die a second lens or secondary optics is fitted and attached over the first lens and serves to shape the beam.