Low-Threshold Continuous-Wave Operation of Electrically Pumped 1.55 μm InAs Quantum Dash Microring Lasers

Abstract

Densely integrated devices on a single chip enable both complex functionality and economy of scale. With a small footprint, microcavities with self-assembled InAs quantum dashes (QDashes) use minimal real estate cost while offering full photonic functionality. Here, the first roomtemperature-continuous-wave (CW) operation of electrically pumped InAs QDash microring lasers in the 1.55 μm telecom window is reported. CW lasing up to 55 °C has been achieved with a low threshold current density of 528 A/cm 2 . The ring laser has only a few unique modes with an extinction ratio over 26 dB for the primary mode. The reduced carrier diffusion length of the QDash active region suppresses the sidewall surface recombination. Feasibility of device miniaturization was demonstrated, with the lowest threshold being 3.5 mA. Since microring cavities do not require feedback mirrors, their compact size and resulting low thresholds make them the ideal candidate for an on-chip light source in optical datacom interconnects.

Photonic Crystal Circular Nanobeam Cavity Laser with Type-II GaSb/GaAs Quantum Rings as Gain Material

“…The QRs have the less abrupt GaSb/GaAs interfaces but larger surface area than QDs do, which improve the wave function overlap between electrons and holes and therefore boost up the radiative recombination significantly 30 . The luminescence from coupled GaSb/GaAs QRs at room temperature can be even comparable to that of type-I InAs QDs 29 , indicating that GaSb QRs might play a role in the applications of laser diodes and light-emitting diodes 28,31 .Recently the novel low-dimensional gain materials such as QW 32,33 , QD 12,13,[34][35][36][37][38] , and two-dimensional materials 39,40 were integrated with compact optical cavities for lasing devices under continuous-wave 32,35,36,40 and electrical injection pumping 34,37,38 conditions. In this study, we demonstrated a photonic crystal (PhC) circular nanobeam defect cavity 41 laser with the type-II GaSb/GaAs QRs as gain medium, for first time.…”

“…Recently the novel low-dimensional gain materials such as QW 32,33 , QD 12,13,[34][35][36][37][38] , and two-dimensional materials 39,40 were integrated with compact optical cavities for lasing devices under continuous-wave 32,35,36,40 and electrical injection pumping 34,37,38 conditions. In this study, we demonstrated a photonic crystal (PhC) circular nanobeam defect cavity 41 laser with the type-II GaSb/GaAs QRs as gain medium, for first time.…”

Vertically coupled InP/InGaAsP microring lasers using a single epitaxial growth and single-side lithography

“…In addition to sidewall roughness in such highly confined structures, surface recombination of injected carriers is one of the major limiting factors to good laser performance. Therefore, optimizing the dry etch process and coating the etched surface with a layer of SiO 2 or passivating it with Al 2 O 3 by atomic layer deposition (ALD) [22] are expected to drastically reduce these sources of loss. The use of quantum dots (QDs) instead of quantum wells as the active media has also shown to be a good strategy to minimize the recombination on the resonator surface and achieve lower threshold lasing in small volume cavities [23].…”

A density functional theory study on mechanism and substituent effects of a base‐free and catalyst‐free synthesis of functionalized dihydrobenzoxazoles

“…For the sake of brevity, we will denote this substrate as R in the rest of this article. All theoretical studies were performed by using the density functional theory (DFT) method, which has become the most prevalent and efficient tool in organic reaction mechanism studies …”