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Research

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Novel Photonic Materials and Fabrication

Shaping novel nanophotonic materials

Silicon Photonics and Non Reciprocity
Silicon Photonics

Enabling the next generation of computing systems

Nano-Electromagnetism

Manipulating waves at the nanoscale

Sensing and Optofluidics

Sensing and manipulating biological analytes

Optomechanics

Controlling the interaction between phonons and photons

Nonlinear Optics

Generating extreme nonlinearities in nanophotonic structures

Silicon Photonics and Non Reciprocity

Published papers (partial list)

Optical Isolator

Achieving on-chip optical isolation using CMOS compatible material is a crucial step toward realizing a complete silicon photonics network. Our approach is utilizing asymmetric mode coupling between even and odd modes in a coupled silicon waveguide region by introducing an effective traveling wave refractive index modulation generated from special design of segmented pn diodes. We have currently achieved 3 dB isolation with operation bandwidth over 200 GHz.

Schematic of the silicon isolator with special design of the segmented pn diodes and the transmission line feeding these diodes.

Initial experimental results of our isolator showing the increase of isolation performance as a function of the electrical signal input power (red). Up to 3 dB isolation is observed.

On-chip Networking

Some of our work, in collaboration with Prof. Keren Bergman at Columbia University, is on network applications of our silicon devices such as high speed data transmission and switching using non-blocking filters.

(a) Colored SEM image of the device used for non-blocking filter operation. The waveguides are in blue, the heaters in brown, and the green identifies the thin Si slab underneath the structure (used for enhanced heat transfer). (b) Photo of final fabricated device showing the Cu wires.


Recent News

Prof. Lipson ranked among top 1% of researchers for most cited papers in physics

Prof. Lipson ranked among top 1% of researchers for most cited papers in physics by Thomas Reuters.