Rod Lenses

Designed for use in a variety of laser and imaging systems, these components are available in a range of micro sizes for integration into a host of OEM applications.COE Optics' Rod Lenses are polished on the circumference and ground on both ends. Optical performance is similar to a cylinder lens. Collimated light passing through the diameter of the rod lens will be focused into a line. N-BK7 and UV Fused Silica substrates are available for a variety of UV, Visible and NIR applications.

• Focuses Collimated Light into a Line
• Available in Diameters as Small as 1mm
• N-BK7 and Fused Silica Substrate Options

Another application of the COE Optics rod lens is working for the rigid endoscope.


The traditional endoscope employs a series of achromatic doublets for the relay optics. Modern endoscopes more typically utilize much longer lenses with length-to-diameter ratios as high as 10. These are the so-called rod lenses. The advantage of the rod lens designs is that the chief ray bundle can be confined more tightly to the optical axis by reducing the ray divergence in the air gaps between the lenses. This reduces Vignetting, one of the most severe problems in small diameter rigid endoscopes. The image also forms further down the endoscope tube, which reduces the number of air-to-glass interfaces in the system.


The mounting of rod lenses is also simpler than thin achromats. The rod lenses tend to tilt less when they are assembled into the inner lens tube. Also, since the spacers are shorter in a rod lens design, they can be made thinner which increases the clear aperture. Rod lenses are typically fine ground on their outer surface to reduce stray reflection. There are now many variations of the rod lens concept, including a design that combines achromatic lenses with long plane-parallel windows.