Fiber- or rod-like Doric GRIN cylindrical microlenses are diffraction-limited microlenses with precise diameters and unsurpassed surface quality. When illuminated sideways, these fibers act as perfect 0.5 NA cylindrical lenses. The fused silica cladding and the gradient-index core of these lenses withstand very high temperatures (their transition temperature is approximately 1100°C). They can be used for visible and near-infrared light.

These lenses are drawn like optical fibers from larger preforms and subsequently cut to desired lengths. Their round cross-section provides a large field of view and simplifies the alignment procedure with the laser diodes. Most of the positioning errors result in simple focusing and beam direction errors. This leads to effective best focus search convenient for automated or manual positioning. These lenses could be used either as fast-axis collimators for single laser diodes or for building cylindrical lens arrays for laser diode bars. Suppose the pitch of laser diode bars or the distance between the laser diode bars is smaller than the lens diameter. In that case, the edges of the lens may be ground, to a certain degree, to the desired width.

The lens core is made of proprietary graded-index material. Its index profile information is available only upon signing a non-disclosure agreement.