Photonic Systems Brown Bag Seminar

Thursday, November 4, 2004, 12 Noon               Haus Room, 36-428, RLE

Microring Filters in Very High Index Contrast:
Design and Fabrication

Milos Popovic & Tymon Barwicz

The idea to use dielectric microring resonators for planar integrated-optical filters stems from the late 1960's when integrated optics was born, but it has taken 30 years for fabrication technology to advance to a level where practical devices can be considered.   To achieve the kind of wide free-spectral range (FSR) that is required for microring filters to be useful as channel add/drop filters in telecom applications, we have turned to very high refractive index contrast (HIC) between the waveguide core and cladding materials.   HIC brings new challenges in both electromagnetic design and device fabrication.

In this seminar, we will describe design and fabrication considerations for HIC microrings and coupled microring filters.   This will include device simulation, effects of coupling-induced frequency shifting, multistage filter arrangements, nanofabrication processes enabling high resolution and accurate dimensional control, and techniques used to precisely frequency match the microrings.   Low-loss filters with flat-top passbands, deep through-port extinction and a wide FSR will be reported.