Rod Lenses

Rod lenses are specialized cylindrical lenses commonly employed in various optical systems. They have a high aspect ratio with a diameter much smaller than their length, This unique design facilitates the efficient transfer of light along the length of the rod, minimizing distortion and aberrations.

These lenses undergo a meticulous process where they are highly polished on the circumference and ground on both ends. The resulting rod lenses perform analogously to standard cylinder lenses, finding applications in beam shaping and the focus of collimated light into a line. Our 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 shaped by grinding the ends to the desired size, enabling customization from microsizes to full-sized lenses. However, caution is to be exercised during handling since they typically lack chamfers.

Rod Lenses in Endoscopy, light transmission, customized rod lenses
Rod Lenses

Rod Lenses for Endoscopy

In endoscopy, polished rod lenses function as circular lenses, and will have the same optical properties as a long circular lens with a narrow diameter. These lenses play an important role in rigid endoscopes, medical devices with a light attached used to look inside the body cavity or organ. A rod lens will self-align to the tube diameter, unlike a traditional microlens. Due to their unique structure, rod lenses provide structural support to the endoscope tube. It is important to use precision-cut lenses and exact surface curvature for endoscopy which lenses provide. 

Barcode Scanners

Rod Lenses play a crucial role in the precise and efficient reading of a barcode. They are used to focus and direct the light emitted from the scanner’s light source onto the barcode. The precision in their design ensures the reliability of barcode scanners in various industries, such as retail, logistics, and manufacturing.

Light Pipes 

Another application that rod lenses provide is acting as a “light pipe”, which transports light through the length of the rod. Total internal reflection (TIR) confines the light within the rod, transforming the exterior into a perfect mirror. This application is common in illumination systems.

Rod Lenses from Avantier

At Avantier, our rod lenses come with substrate options, including Schott glass, Ohara glass, CDGM, Corning Fused Silica, JGS1, and JGS2. To ensure that each of our rod lenses complies with all relevant standards, we utilize state-of-the-art metrology equipment for rigorous quality control measures.

We can provide variations in polishing ground surfaces depending on the desired application. For example, rod lenses intended for end-to-end use can be polished on both the circumference and ground ends.

Our factory standard guarantees a clear aperture of 90% of the central dimension, coupled with a focal length tolerance of +/-1%. The surface quality of relevant polished surfaces adheres to the 40-20 scratch-dig industry standard, ensuring high optical performance.

With a surface irregularity of λ/4, which is excellent for imaging and general laser applications, we encourage those considering high-powered laser or other specialized applications to reach out and discuss our manufacturing limits.

Rod Lenses in Endoscopy, light transmission, customized rod lenses
Rod Lenses

Factory Standard

Substrate Material

Schott, Ohara, CDGM, Corning Fused Silica and JGS1, JGS2

Shape

Rod

Focal length

+/-1%

Surface Quality

40-20

Surface Irregularity

l/4 @ 633nm

Clear Aperture

>90% of central dimension

Angle

+/-5″

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.

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