Multi-Spectral Quantum Cascade Lasers on Silicon With Integrated Multiplexers

• Main Authors: Eric J. Stanton, Alexander Spott, Jon Peters, Michael L. Davenport, Aditya Malik, Nicolas Volet, Junqian Liu, Charles D. Merritt, Igor Vurgaftman, Chul Soo Kim, Jerry R. Meyer, John E. Bowers
• Format: Article
• Language: English
• Published: MDPI AG 2019-01-01
• Series: Photonics
• Subjects: quantum cascade laser; silicon photonics; distributed feedback laser; mid-infrared; arrayed waveguide grating
• Online Access: https://www.mdpi.com/2304-6732/6/1/6
• ISSN: 2304-6732

Multi-spectral midwave-infrared (mid-IR) lasers are demonstrated by directly bonding quantum cascade epitaxial gain layers to silicon-on-insulator (SOI) waveguides with arrayed waveguide grating (AWG) multiplexers. Arrays of distributed feedback (DFB) and distributed Bragg-reflection (DBR) quantum cascade lasers (QCLs) emitting at ∼4.7 µm wavelength are coupled to AWGs on the same chip. Low-loss spectral beam combining allows for brightness scaling by coupling the light generated by multiple input QCLs into the fundamental mode of a single output waveguide. Promising results are demonstrated and further improvements are in progress. This device can lead to compact and sensitive chemical detection systems using absorption spectroscopy across a broad spectral range in the mid-IR as well as a high-brightness multi-spectral source for power scaling.