Enhanced poling and infiltration for highly efficient electro-optic polymer-based Mach-Zehnder modulators
Abstract
An ultra-narrow 40-nm slotted waveguide is fabricated to enable highly efficient, electro-optic polymer modulators. Our measurement results indicate that VπL’s below ∼ 1.19 V.mm are possible for the balanced Mach-Zehnder modulators using this ultra-narrow slotted waveguide on a hybrid silicon-organic hybrid platform. Our simulations suggest that VπL’s can be further reduced to ∼ 0.35 V.mm if appropriate doping is utilized. In addition to adapting standard recipes, we developed two novel fabrication processes to achieve miniaturized devices with high modulation sensitivity. To boost compactness and decrease the overall footprint, we use a fabrication approach based on air bridge interconnects on thick, thermally-reflowed, MaN 2410 E-beam resist protected by an alumina layer. To overcome the challenges of high currents and imperfect infiltration of polymers into ultra-narrow slots, we use a carefully designed, atomically-thin layer of TiO2 as a carrier barrier to enhance the efficiency of our electro-optic polymers. The anticipated increase in total capacitance due to the TiO2 layer is negligible. Applying our TiO2 surface treatment to the ultra-narrow slot allows us to obtain an improved index change efficiency (∂n/∂V) of ∼ 22% for a 5 nm TiO2 layer. Furthermore, compared to non-optimized cases, our peak measured current during poling is reduced by a factor of ∼ 3.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 15, 2022
- Source ID
- 10.1364/oe.460830
Entities
People
- Alexander Tofini
- Ali Adibi
- Ali. A. Efterkhar
- Hesam Moradinejad
- Iman Taghavi
- Lukas Chrostowski
- Nicolas A. F. Jaeger
- Razi Dehghannasiri
- Sudip Shekhar
- Tianren Fan
Organizations
- Canada Foundation for Innovation
- Defense Advanced Research Projects Agency
- Georgia Tech
- National Science Foundation
- Natural Sciences and Engineering Research Council
- University of British Columbia