Subwavelength Nanopatch Cavities for Semiconductor Plasmon Lasers

TL;DR

This paper introduces nanoscale surface plasmon cavities for semiconductor lasers that enable efficient, subwavelength optical confinement and beam shaping, potentially leading to compact, high-performance laser devices.

Contribution

It proposes a novel family of nanoscale plasmonic cavities for semiconductor lasers, demonstrating their potential for efficient mode confinement and beam control at subwavelength scales.

Findings

Cavity losses can be compensated by strong mode confinement.

Surface plasmons enable narrow far-field beam patterns.

Threshold gain can be below 700 1/cm in near-IR range.

Abstract

We propose and analyze a family of nanoscale cavities for electrically-pumped surface-emitting semiconductor lasers that use surface plasmons to provide optical mode confinement in cavities which have dimensions in the 100-300 nm range. The proposed laser cavities are in many ways nanoscale optical versions of micropatch antennas that are commonly used at microwave/RF frequencies. Surface plasmons are not only used for mode confinement but also for output beam shaping to realize single-lobe far-field radiation patterns with narrow beam waists from subwavelength size cavities. We identify the cavity modes with the largest quality factors and modal gain, and show that in the near-IR wavelength range (1.0-1.6 microns) cavity losses (including surface plasmon losses) can be compensated by the strong mode confinement in the gain region provided by the surface plasmons themselves and the required material threshold gain values can be smaller than 700 1/cm.