A Rod lens is a special type of cylinder lens, and is highly polished on the circumference and ground on both ends. Rod lenses perform in a manner analogous to a standard cylinder lens, and can be used in beam shaping and to focus collimated light into a line. Our rod lenses play a key part in many laser and imaging optical assemblies, and can be used for UV, visible and NIR applications.
Our Fused Silica Rod Lens offers particularly high transmission in the UV and through the NIR as well as a low coefficient of thermal expansion, 0.55 x 10E6 per °C. The refractive index of our JGS1 fused silica is 1.4585.
Cut-rod lenses are derived from longer mother rods; the ends are ground to the desired size. This allows us to provide custom sizes as desired, from microsizes to full-sized lenses. As rod lenses are not typically chamfered, you will need to use caution when handling.
When the ends of rod lenses are polished they may be used as circular lenses, and will have the same optical properties as a long circular lens with a narrow diameter. These lenses have an important application in rigid endoscopes, medical instruments used to view inside the human body. Unlike a traditional microlens, a rod lens will self-align to the tube diameter. Their unique shape means they can also provide structural support to the endoscope tube. For endoscopy used precision cut lenses and exact surface curvature are essential.
Another application of a rod lens with ends polished is as a ‘light pipe” which transports light through the length of the rod. Total internal reflection (TIR) confines the light passing within the rod, and makes the exterior act as a perfect mirror. Rod lenses are often used in this manner in illumination systems.
Substrate options for our rod lenses include Schott glass, Ohara glass, CDGM, Corning Fused Silica, JGS1 and JGS2. We use the utmost care to ensure that each of our rod lenses fully meets all applicable standards, and our state of the art metrology equipment allows us to provide thorough quality control.
Depending on desired application, we can provide variations in polishing ground surfaces. For instance, rod lenses meant for end to end use can be polished on both the circumference and ground ends.
Our factory standard ensures a clear aperture of 90% of the central dimension, and a focal length tolerance of +/-1%. The surface quality of relevant polished surfaces is 40-20 scratch-dig. This is industry standard for precise laser applications, and ensures high optical performance.
Surface irregularity is λ/4, which is considered excellent for imaging and general laser applications. For high powered laser or other applications, please contact us to discuss our manufacturing limit.
Please contact us for manufacturing limit or to discuss custom specifications. Our team is highly experienced in optical design and will be assist in all stages of design and production.