III-V microlaser in silicon photonic circuits can be made with industrial fabrication techniques

Dec. 6, 2016
Whispering-gallery laser cavity is only a couple of microns in diameter.

Because silicon itself does not easily lase, using III-V semiconductor materials that can lase, such as indium gallium arsenide phosphide (InGaAsP) and others, is a time-honored way to add lasers to silicon photonic circuits. This is often done by bonding a prefabricated III-V laser-diode structure to a silicon photonic circuit.

Now, Doris Keh-Ting Ng and colleagues from the A*STAR Data Storage Institute (Singapore) have produced very compact version of these hybrid devices that could lead to micrometer-scale lasers for use in small and rugged barcode scanners, for example.

The team started with a silicon substrate onto which they deposited a thin layer of silicon oxide (SiO2). The 210-nm-thick optically active InGaAsP film was fabricated separately and then bonded on top of the SiO2. The team then etched through some of the material to create cylinders either 2 or 3 μm in diameter. The 3 μm devices emitted laser light with a wavelength of 1519 nm, very close to that used in commercial optical communications systems.

The laser cavity was based on a whispering-gallery geometry; the 2-μm-diameter cavity had a mode volume of only 0.07 Λ3 and a Q (quality) factor of 1.3×104.

Source: http://www.research.a-star.edu.sg/research/7611/mix-and-match-lasers

REFERENCE:

1. Lee, C.-W. et al., Optics Letters 41, 3149–3152 (2016); https://doi.org/10.1364/OL.41.003149.

About the Author

John Wallace | Senior Technical Editor (1998-2022)

John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!