Heterogeneous 2D/3D photonic integrated microsystems

Researchers in the United States have demonstrated a combination of 2D and 3D microstructures that control the flow of light for ultrafast data processing. One common technique for fabricating these integrated photonic circuits is to use ultrafast lasers to write arbitrarily shaped optical circuitry directly into a dielectric material. A less-flexible alternative is to stack more-easily created 2D layers to form a 3D structure. S. J. Ben Yoo and his co-workers from the University of California, Davis, investigated how combining the 2D and 3D approaches could provide the best devices for certain applications. They applied this idea to build a multiplexer that combines beams with different orbital angular momentum and to demonstrate an optical beam steering module. The newly combined 2D/3D microsystem with optical path length matching enables it to support optical signal processing and transmission in the spatial, temporal, and spectral domains in both polarizations.