Title: Metasurface quantum-cascade laser with electrically switchable polarization

Abstract

Dynamic control of a laser’s output polarization state is desirable for applications in polarization sensitive imaging, spectroscopy, and ellipsometry. Using external elements to control the polarization state is a common approach. Less common and more challenging is directly switching the polarization state of a laser, which, however, has the potential to provide high switching speeds, compactness, and power efficiency. Here, we demonstrate a new approach to achieve direct and electrically controlled polarization switching of a semiconductor laser. This is enabled by integrating a polarization-sensitive metasurface with a semiconductor gain medium to selectively amplify a cavity mode with the designed polarization state, therefore leading to an output in the designed polarization. Here, the demonstration is for a terahertz quantum-cascade laser, which exhibits electrically controlled switching between two linear polarizations separated by 80°, while maintaining an excellent beam with a narrow divergence of ~3°×3° and a single-mode operation fixed at ~3.4 THz, combined with a peak power as high as 93 mW at a temperature of 77 K. The polarization-sensitive metasurface is composed of two interleaved arrays of surface-emitting antennas, all of which are loaded with quantum-cascade gain materials. Each array is designed to resonantly interact with one specific polarization; when electricalmore » bias is selectively applied to the gain material in one array, selective amplification of one polarization occurs. The amplifying metasurface is used along with an output coupler reflector to build a vertical-external-cavity surface-emitting laser whose output polarization state can be switched solely electrically. In conclusion, this work demonstrates the potential of exploiting amplifying polarization-sensitive metasurfaces to create lasers with desirable polarization states—a concept which is applicable beyond the terahertz and can potentially be applied to shorter wavelengths.« less

Authors:

Xu, Luyao ^[1]; Chen, Daguan ^[2]; Curwen, Christopher A. ^[1]; Memarian, Mohammad ^[2]; Reno, John L. ^[3]; Itoh, Tatsuo ^[2]; Williams, Benjamin S. ^[1]

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+ Show Author Affiliations

1. Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Univ. of California, Los Angeles, CA (United States). California NanoSystems Inst.
2. Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center of Integrated Nanotechnologies

Publication Date:

Thu Apr 20 00:00:00 EDT 2017

Research Org.:

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF); National Aeronautics and Space Administration (NASA)

OSTI Identifier:

1360798

Report Number(s):

SAND-2016-12371J
Journal ID: ISSN 2334-2536; 649740

Grant/Contract Number:  

AC04-94AL85000

Resource Type:

Accepted Manuscript

Journal Name:

Optica

Additional Journal Information:

Journal Volume: 4; Journal Issue: 4; Journal ID: ISSN 2334-2536

Publisher:

Optical Society of America

Country of Publication:

United States

Language:

English

Subject:

47 OTHER INSTRUMENTATION