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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 21, Iss. 26 — Dec. 30, 2013
  • pp: 31951–31959

An investigation on optimum ridge width and exposed side strips width of terahertz quantum cascade lasers with metal-metal waveguides

Chao Xu, Seyed Ghasem Razavipour, Zbigniew Wasilewski, and Dayan Ban  »View Author Affiliations

Optics Express, Vol. 21, Issue 26, pp. 31951-31959 (2013)

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The impacts of side exposed side strips (for high order modes suppression) and ridge width on terahertz (THz) quantum cascade laser (QCL) performance are investigated through numerical modeling and verified experimentally. Our results show that shrinking ridge width of THz QCLs with metal-metal waveguides leads to a substantial degradation of device performance due to higher optical loss resulting from the side-exposed strips in the highly-doped top contact layer. Nevertheless, the side-exposed strips facilitate single mode operation by strongly suppressing higher-order modes. An optimal width of the side exposed strips is obtained for achieving adequate higher-order mode suppression and maintaining sufficiently low fundamental mode loss.

© 2013 Optical Society of America

OCIS Codes
(140.3070) Lasers and laser optics : Infrared and far-infrared lasers
(140.5960) Lasers and laser optics : Semiconductor lasers

ToC Category:
Lasers and Laser Optics

Original Manuscript: November 18, 2013
Revised Manuscript: December 8, 2013
Manuscript Accepted: December 8, 2013
Published: December 16, 2013

Chao Xu, Seyed Ghasem Razavipour, Zbigniew Wasilewski, and Dayan Ban, "An investigation on optimum ridge width and exposed side strips width of terahertz quantum cascade lasers with metal-metal waveguides," Opt. Express 21, 31951-31959 (2013)

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