Grin lens based astigmatism correcting optical coupler

摘要

An astigmatism-correcting coupler includes a collimating lens for collimating a beam of coherent light output from a laser, a power adjusting lens for reducing any astigmatism of the collimated beam of coherent light output, and a focusing lens for focusing the collimated beam of coherent light output into an optical fiber. The focusing lens is a graded-index (GRIN) focusing lens that is cylindrically polished to have different focal powers in lateral and transverse planes. The cylindrical polished GRIN focusing lens corrects for astigmatic effects by adjusting the power of the light output on the transverse and lateral planes.