Dielectric deposition for tuning the frequency of THz quantum cascade lasers

B. Mirzaei*, D. J. Hayton, D. Thoen, J. R. Gao, T. Y. Kao, Q. Hu, J. L. Reno

*Corresponding author for this work

    Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

    Abstract

    We report an extensive study of the effect of an additional dielectric layer on the frequency of terahertz quantum cascade lasers (QCLs). QCLs with third-order distributed feedback structure at frequencies of 3.5 and 4.7 THz are used in our experiment. The dielectric layer applied is either Silicon-dioxide (SiO2) or Polymethylmethacrylaat (PMMA). We find that both dielectric layers can down shift the lasing frequency up to 6GHz on a 3.5THz QCL, and 13GHz for a 4.7THz QCL. Full 3D FEM simulations suggest that the effect is dominated by the effective thickness of the dielectric on the vertical walls of the laser structure, and also confirm that for a given dielectric layer the effect is stronger in the 4.7THz QCL due to its larger out-distribution of electric-magnetic field. The knowledge provides guideline to shift the frequency of an existing QCL used as a local oscillator in practical applications.

    Original languageEnglish
    Title of host publicationISSTT 2017 - 28th International Symposium on Space Terahertz Technology
    EditorsImran Mehdi
    PublisherISSTT2017
    Number of pages14
    Volume2017-March
    ISBN (Electronic)978-1-5108-5972-2
    Publication statusPublished - 2017
    Event28th International Symposium on Space Terahertz Technology, ISSTT 2017 - Cologne, Germany
    Duration: 13 Mar 201715 Mar 2017

    Conference

    Conference28th International Symposium on Space Terahertz Technology, ISSTT 2017
    CountryGermany
    CityCologne
    Period13/03/1715/03/17

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