Efficient dielectric metasurface collimating lenses for mid-infrared quantum cascade lasers
- California Institute of Technology, Pasadena, CA (United States). T. J. Watson Laboratory of Applied Physics
- California Institute of Technology, Pasadena, CA (United States). Jet Propulsion Laboratory
Light emitted from single-mode semiconductor lasers generally has large divergence angles, and high numerical aperture lenses are required for beam collimation. Visible and near infrared lasers are collimated using aspheric glass or plastic lenses, yet collimation of mid-infrared quantum cascade lasers typically requires more costly aspheric lenses made of germanium, chalcogenide compounds, or other infrared-transparent materials. We report mid-infrared dielectric metasurface flat lenses that efficiently collimate the output beam of single-mode quantum cascade lasers. The metasurface lenses are composed of amorphous silicon posts on a flat sapphire substrate and can be fabricated at low cost using a single step conventional UV binary lithography. Mid-infrared radiation from a 4.8 μm distributed-feedback quantum cascade laser is collimated using a polarization insensitive metasurface lens with 0.86 numerical aperture and 79% transmission efficiency. The collimated beam has a half divergence angle of 0.36° and beam quality factor of M² =1.02.
- Research Organization:
- California Institute of Technology (CalTech), Pasadena, CA (United States); Energy Frontier Research Centers (EFRC) (United States). Light-Material Interactions in Energy Conversion (LMI)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC0001293
- OSTI ID:
- 1239526
- Journal Information:
- Optics Express, Vol. 23, Issue 26; ISSN 1094-4087
- Publisher:
- Optical Society of America (OSA)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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