On-chip focusing in the mid-infrared: Demonstrated with ring quantum cascade lasers

Journal Article · Mon Apr 14 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4871520· OSTI ID:22262629

Szedlak, Rolf; Schwarzer, Clemens; Zederbauer, Tobias; Detz, Hermann; Maxwell Andrews, Aaron; Schrenk, Werner; Strasser, Gottfried ^[1]

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1. Institute for Solid State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, 1040 Vienna (Austria)

We report on collimated emission beams from substrate emitting ring quantum cascade lasers with an on-chip focusing element fabricated into the bottom side of the device. It is formed by a gradient index metamaterial layer, realized by etching subwavelength holes into the substrate. The generated optical path length difference for rays emitted under different angles from the ring waveguide flattens the wavefront and focuses the light. Our far field measurements show an increased peak intensity corresponding to 617% of the initial value without the focusing element. Far field calculations, based on a Fourier transformation of the metamaterial area, are in good agreement with our experimental data.

• OSTI ID: 22262629
• Journal Information: Applied Physics Letters, Vol. 104, Issue 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
42 ENGINEERING
EQUIPMENT
ETCHING
FOCUSING
INFRARED RADIATION
LASERS
SUBSTRATES