Deformed Honeycomb Lattices of InGaAs Nanowires Grown on Silicon‐on‐Insulator for Photonic Crystal Surface‐Emitting Lasers

Abstract

excellent narrow beam divergence [7] make them highly promising for light detection and ranging [8] and optical sensing applications. Conventionally, top-down nanofabrication processes are used for fabricating PhC surface-emitting lasers (PCSELs) as well as emerging topological cavity surface-emitting lasers. [9][10][11][12] Over the last few years, selective area, catalyst-free growth of nanowires has progressed rapidly, providing a unique platform for ultracompact bottom-up PhC lasers. [13][14][15][16] In comparison to top-down etched PhC cavities, the vertical and atomically flat sidewall surface and the ability to form in situ passivation layers in nanowire growth minimize scattering and propagation losses and thereby preserve high radiative recombination efficiency. By breaking or relaxing the constraints from materials lattice mismatch, combining dissimilar materials into 3D axial and core-shell structures with strong quantum confinement and direct epitaxial integration on technologically important substrates such as silicon-on-insulator (SOI) chips also become possible. Optically pumped lasing from a lift-off 2D GaAs/InGaAs/GaAs nanowire arrays was realized emitting at wavelengths between 960 and 989 nm. [17] Near vertical surface emission around 850 nm from an InP nanowire PhC structure on InP substrate was recently reported, exhibiting pulse lasing at room temperature as well as continuous-wave lasing at 77 K with an output power of 470 µW. [18] Electrically pumped surface-emitting laser diodes using bottom-up PhC cavities have so far only been achieved by InGaN/AlGaN nanowires [1] and remain one of the biggest challenges in III-As/P based nanowires. For practical integration of nanowire lasers with silicon photonic integrated circuits and silicon electronics, direct growth of nanowire lasers on silicon operating in the relevant telecom spectral bandwidth (1.3-1.55 µm) is crucial. To date, this has been developed using either bandgap tunable InGaAs nanowire-based 1D or 2D PhC arrays [15,[19][20][21] or straincompensated InGaAs/(In,Al)GaAs multiquantum-well nanowires. [22] Despite impressive waveguide-coupled lasing at room temperature and low-threshold characteristics that have been demonstrated, a surface-emitting telecom wavelength nanowire PhC laser, which could be of great interest for optical sensing applications, has not been reported yet.Photonic crystals can be used to achieve high-performance surface-emitting lasers and enable novel photonic topological insulator devices. In this work, a GaAs/InGaAs heterojunction nanowire platform by selective area metalorganic vapor phase epitaxy for such applications is demonstrated. The nanowires are arranged into deformed honeycomb lattices on silicon-on-insulator substrate to exploit the quadrupolar photonic band-edge mode. Coreshell and axial heterostructures are formed with their crystalline properties studied by scanning transmission electron microscopy. Room-temperature, single mode lasing from both stretched and compressed honeycomb lattices within th...

Lateral Tunnel Epitaxy of GaAs in Lithographically Defined Cavities on 220 nm Silicon-on-Insulator

“…The two vertical {110} facets are formed at both sides of the GaAs islands as indicated by the white dotted line in Figure 2b, similar to other selective growth of III−V nanoridges and vertical III−V nanowires with six {110} side-facets. 26,27 By further increasing of the growth rate, a continuous GaAs layer could be obtained, as indicated by Figure 2c. The GaAs growth time was kept at 60 min in these three samples.…”

Recent progress in epitaxial growth of dislocation tolerant and dislocation free III–V lasers on silicon

“…The vertical and smooth side-facets and the capability of in-situ surface passivation can offer both minimized optical propagation loss and reduced non-radiative surface recombination [114]. The catalyst-free selective growth approach has yielded nanowire arrays with high uniformity, which have been implemented for photonic crystal defectmode lasers, band edge lasers and topological photonic cavities [114][115][116][117][118][119][120][121][122][123]. Table 3 chronologically lists the key metrics of these photonic crystal nanowire lasers.…”

“…nanowire diameter, pitch) on the same chip creates exciting opportunities for emerging topological lasers. A deformed honeycomb lattice structure, including both stretched and compressed honeycomb lattices made of InGaAs/GaAs nanowires, has been realized on SOI substrates for highly directional vertical emission at the Γ point [123]. Room-temperature photonic band edge mode lasing at the 1.3 µm wavelength has been achieved.…”