Fabrication of optical-mode converters for efficient fiber-to-silicon-waveguide couplers

Optical-mode converters are needed to efficiently couple light from an optical fiber to a photonic circuit by matching and transforming the propagating modes. This work is based on a horizontally-tapered coupler, in which light from an optical fiber is coupled into a large polymer waveguide and then gradually transferred to a smaller silicon waveguide whose width increases with distance along the guide. Several devices were designed and fabricated to measure the efficiency of the coupler. E-beam exposure doses and writing strategies were optimized to create the tapered silicon waveguides. A fabrication process was developed to form the polymer waveguides without etching the underlying silicon, and a set of marks was created to achieve sub-micron alignment between the two waveguides. Fabrication results showed that the coupler successfully transfers light between the two waveguides and that there is low loss in the polymer. A more accurate characterization of the coupler's efficiency was delayed due to fabrication problems not related to the developed process.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Barreto, Raúl E

Advisor dc:contributor.advisor

• Henry I. Smith.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/41249

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/41249