Fresnel Lenses are used in many light collection applications, such as condenser systems or emitter/detector setups. Fresnel Lenses are optical lenses consisting of a series of concentric grooves etched into a plastic substrate. Each groove acts as an individual refracting surface, while the thin substrate minimizes the amount of light lost due to absorption. High groove density increases image quality, while low groove density increases the overall efficiency. Fresnel Lenses are typically not used as magnifier or projection lenses due to high levels of distortion.
Edmund Optics offers a variety of Fresnel Lenses designed for visible or infrared applications. For maximum performance, the grooved side of a Fresnel Lens should face the longer conjugate. For example, when used with detectors, the grooved side should face away from the detector. Contoured lenses are available to improve focusing performance or spot size. Cylinder Fresnel Lenses are also available to focus in only a single dimension.