Electromagnetic modeling of terahertz quantum cascade laser waveguides and resonators

Finite-element numerical modeling and analysis of electromagnetic waveguides and resonators used in terahertz (THz) quantum cascade lasers (QCLs) is presented. Simulations and analysis of two types were performed: two-dimensional waveguides, and two- and three-dimensional resonators. Both metal-metal and semi-insulating (SI) surface-plasmon geometries were investigated. Waveguide simulations extend previous one-dimensional analyses to two dimensions; resonator simulations in two and three dimensions are presented for the first time. The waveguide simulations quantitatively show when two-dimensional effects become non-negligible in their effect titatively show when two-dimensional effects become non-negligible in their effect on the figure-of-merit relative to previous one-dimensional analyses. The resonator simulations quantitatively show the hybrid optical/microwave nature of THz facet reflectivities, demonstrating that both the effective index method and the impedance mismatch method are poor methods in calculating mirror reflectivities for metal-metal waveguides in the THz region. The effective index method is shown to still be valid for SI surface-plasmon waveguides. In addition, simulated radiation patterns are presented for both waveguiding structures.

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

2004

Author dc:creator

• Kohen, Stephen Michael, 1980-

Advisor dc:contributor.advisor

• Qing Hu.

• 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/1721.1/18058

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/18058