Edmund Optics has introduced its new Gradient Index (GRIN) Rod Lenses. These lenses feature plane optical surfaces and achieve focus using a continuous change of the refractive index within the lens material. GRIN lenses eliminate complex geometries, such as aspherical surface figures, and are carefully designed for specific working distances. As they have a flat surface, these micro lenses are easy for the user to handle and integrate into optical systems, forming an excellent joint to other optical surfaces and bonding well to fibre optics. They are comparable in performance to conventional aspherical singlets. The GRIN Rod Lenses are perfect for fibre coupling and laser diode beam shaping.
The GRIN lenses are designed to provide a 0.55 numerical aperture and are available in two working distance options. Lenses with 0mm working distance are ideally suited for collimation of single and multi-mode optical fibres and laser diodes, as the lens can be positioned and glued directly to the emission source. For focusing applications, or in situations where the lens cannot be in direct contact with the emission source, all lenses are also available with a small working distance.
The GRIN Rod Lenses are available in three sizes and three wavelength options. Each lens is available either uncoated (approximately 12 per cent reflection loss) or with a BBAR coating option for R>0.5 per cent. The lenses are manufactured from an Alumoscilate Glass substrate embedded with silver ions. Lenses are available in 0.5mm, 1.0mm and 1.8mm diameters for 670nm, 810nm and 1550nm wavelengths.