Abstract

An off-axis graded index (GRIN) polymer waveguide chirped grating lens working at 632.8 nm was demonstrated for the first time on a GaAs substrate. The chirped grating lens was formed by using a holographic method. A waveguide lens was constructed with a focal length of 3.3 cm and a lens aperture of 3.3 mm. A diffraction-limited focusing spot was observed. The waveguide lens reported here is a phase grating lens that fully overlaps the guiding layer. Thus, the diffraction efficiency is higher than for a surface-relief-type grating lens with the same index modulation. Diffraction efficiency of 56% was experimentally confirmed. The photo lime gel polymer employed has an index modulation as high as 0.2. Therefore, a large number of chirped grating lenses can be multiplexed onto the same holographic emulsion. Two multiplexed chirped grating lenses were further demonstrated. An important application of this result is the two-dimensional fan-out capability not achievable through conventional integrated optic devices.

© 1992 Optical Society of America