Gaussian beams on a silicon-on-insulator chip using integrated optical lenses

An on-chip optical lens, which can launch expanded and well-collimated Gaussian beams in planar free space with control over propagation angles has been designed, fabricated, and characterized. The results agree well with simulations, maintaining a beam width between 26- and 28-μm beam width even after 750-μm propagation in free space on a silicon chip. Changing the position of the launched field enables the propagation angle to be varied. Both continuous and discrete angle variations have been experimentally demonstrated.