Method for directly measuring loss, polarization state, dispersion, and signal dynamics in photonic integrated circuits (PICs)


The state of the art in photonic circuit testing requires either cumbersome probes or requires fibers to be aligned to coupling locations at the edge of the die. It has been well known for some time that a sensitive microscope camera combination can detect even weakly scattered light from random defects in a photonic waveguide. However, this scattered signal does not carry reliable quantitative information about the waveguide and circuit functionality. In particular, parameters such as loss, polarization state, dispersion, and signal dynamics are not easily obtained through randomly scattered light. 

Technology Overview

The invention described here makes use of small scatterers designed into the circuit as part of the foundry process that will scatter known amounts of light with a known polarization state into a microscope design for collecting and imaging light from photonic integrated circuits. The scatterer is much less than one wavelength in dimension and will therefore scatter light in a manner similar to a dipole antenna, where the polarization of the dipole aligns with the polarization state of the waveguide mode. 


This technique is able to quantify loss, polarization state, dispersion, as well as signal dynamics throughout the chip simultaneously. This represents a massive parallelization of the quality assurance processes required to validate a photonic integrated chip.


Quality assurance of photonics integrated circuits.

URV Reference Number: 2-21015
Patent Information:
For Information, Contact:
Curtis Broadbent
Licensing Manager
University of Rochester
Thomas Brown
Debra Saulnier
Tyler Howard