Mid-infrared integrated resonators on a III-V platform with Q-factors beyond half a million

TL;DR

This paper reports the development of mid-infrared integrated resonators on a III-V platform with exceptionally high Q-factors exceeding half a million, demonstrating low optical losses and promising applications in nonlinear mid-IR photonics.

Contribution

The work introduces mid-IR integrated resonators with record-high Q-factors on a III-V platform, along with comprehensive loss characterization at key atmospheric transparency wavelengths.

Findings

Achieved Q-factors over 600,000 at 4.6 um

Measured low propagation losses of 0.28 dB/cm at 4.6 um

Demonstrated potential for nonlinear mid-IR device development

Abstract

We demonstrate mid-IR integrated race-track resonators on a III-V semiconductor platform,InGaAs core epitaxially grown on InP. We have performed a complete characterization of the optical propagation losses at wavelength = 4.6 um and wavelength = 8.5 um, two representative wavelengths for the 1st and 2nd atmospheric transparency windows. We measured losses of 1 dB/cm (TE polarization) and 1.3 dB/cm (TM polarization) at 8.5 um. Substantially lower losses, 0.28 dB/cm, were measured at wavelength = 4.6 um (TM polarization). We then implemented racetrack resonators with straight evanescent couplers. We obtained loaded quality factors larger than 600.000 at wavelength = 4.6 um. These results are promising towards the development of non-linear mid-IR integrated devices with Q factors beyond a million, where the onset of stimulated parametric processes could be reachable.