We present the extraction of recombination coefficients for electrically injected monolithic nano-ridge laser diodes by first determining the effective carrier capture time from the small signal modulation response. The effect of the nano-ridge box size on the recombination coefficients is investigated.

The static and dynamic characteristics of electrically injected monolithic nano-ridge lasers emitting around the wavelength of 1030 nm are comprehensively investigated, providing critical insights into their performance and identifying pathways for future improvement. Key laser parameters such as the D-factor, the K-factor, the differential gain and the gain compression factor are extracted. Recombination coefficients and carrier escape times are determined by taking the effective carrier capture times derived from the small-signal modulation response. Additionally, the impact of the nano-ridge box size on the recombination coefficients is evaluated, highlighting the role of structural design in optimizing device performance and reliability.

We present a semi-analytical model that can accurately explain the working principle behind the recently reported electrically injected In0.2Ga0.8As/GaAs monolithic nano-ridge lasers and more importantly show how the model can be used to study the effect of device parameters on the spectral behavior, the slope efficiency and the threshold gain. We show that mode beating between the fundamental mode and a higher order mode is fundamental in the operation of these lasers. Analytical expressions for codirectional mode coupling are used in developing the round-trip laser model. Results from analytical expressions are verified by comparisons with simulations and the model is supported later by measurement results.

We present assembly results for a variety of single channel and array-based InP lasers built on the Sivers Photonics InP100 platform, combined with imec's 200 mm SiPho platform, and leveraging the sub-micron placement capabilities of the ASMPT AMICRA NANO. This focuses on the scaling from single devices ($0.3 \times 0.35 \text{mm}$) to $4 \times(0.8 \times 0.5 \text{mm})$ and $8 \times(1.6 \times 0.5 \text{mm})$ array devices, considering the interaction between the bond tool, device, landing site and processing conditions. Furthermore, we discuss how alignment strategies and the choice of alignment markers and bonding parameters can be fine-tuned to minimize misalignment in the XY plane and in the rotation of the bonded devices. In addition, we utilise white light interferometry to determine any warp or bow present in the device and how that may affect the individual channels in a multi-channel device. Finally, we use LIV curves as our primary determinant of how successful the bonding is, with both inter- and intra-device comparisons. We report post-bond results with $<500 \text{nm}$ misalignment in the XY plane, $<0.065^{\circ}$ rotational misalignment and $<500 \text{nm}$ tilt across a variety of device shapes and sizes and best device outputs of 25 mW and 2.5 dB coupling loss.

Silicon photonics is a rapidly developing technology that promises to revolutionize the way we communicate, compute, and sense the world. However, the lack of highly scalable, native CMOS-integrated light sources is one of the main factors hampering its widespread adoption. Despite significant progress in hybrid and heterogeneous integration of III-V light sources on silicon, monolithic integration by direct epitaxial growth of III-V materials remains the pinnacle in realizing cost-effective on-chip light sources. Here, we report the first electrically driven GaAs-based multi-quantum-well laser diodes fully fabricated on 300 mm Si wafers in a CMOS pilot manufacturing line. GaAs nano-ridge waveguides with embedded p-i-n diodes, InGaAs quantum wells and InGaP passivation layers are grown with high quality at wafer scale, leveraging selective-area epitaxy with aspect-ratio trapping. After III-V facet patterning and standard CMOS contact metallization, room-temperature continuous-wave lasing is demonstrated at wavelengths around 1020 nm in more than three hundred devices across a wafer, with threshold currents as low as 5 mA, output powers beyond 1 mW, laser linewidths down to 46 MHz, and laser operation up to 55 {\deg}C. These results illustrate the potential of the III-V/Si nano-ridge engineering concept for the monolithic integration of laser diodes in a Si photonics platform, enabling future cost-sensitive high-volume applications in optical sensing, interconnects and beyond.

We report a multi-channel hybrid external-cavity-laser (ECL) array using a flip-chip bonded InP RSOA on 200 mm silicon photonics platform with integrated LPCVD SiN DBR mirror. The resulting ECL demonstrates 25 mW waveguide-coupled power and single-mode operation using integrated Si-based phase tuning.

The reliability of In0.2Ga0.8As/GaAs nano-ridge photodetectors monolithically integrated on 300 mm Si substrates is first reported. Dark current increases and saturates at 2×10-5 A/cm2 at 85 °C after stress, which is still sufficiently low. Carrier emission from pre-existing defects is identified as the dominant degradation mechanism.

Microcellular polyurethane (MCU) foams are used in many industrial applications. Their effective properties are closely related to their microstructure. Being able to characterize their microstructure is therefore particularly useful for designing them or improving the quality control of parts on production lines. This paper presents tools developed to quantitatively characterize the cellular microstructure of MCU. The goal is to propose a method that is accessible to academic and industry laboratories. The paper investigates the possibility of using scanning electron microscope images to perform this characterization automatically, quantitatively, and with sufficient statistics. To evaluate the relevance and limitations of the approach, the results are compared to data obtained by analysing X-ray micro-computed tomography images obtained on the same samples. To challenge the methodology, the study is conducted on twelve samples with densities between 400 and 600 kg m(-3) and different cellular microstructures. A relevant image processing procedure is developed to detect the cells from the acquired images, automatically and objectively. The fraction, size, shape and spatial distribution of the cells are analysed. The difference between 2D and 3D measurements is investigated. The minimum size of the area to analyse, which guarantees the representativeness of the results from a statistical point of view, is determined.

We demonstrate heterogeneously integrated passively mode-locked lasers by microtransfer printing III-V semiconductor optical amplifiers on a silicon nitride photonic chip. A dense and low-noise optical comb is generated, enabling unparalleled precision for on-chip spectroscopy.

We propose an efficient heat channel for SiN based tunable devices which are critical for narrow-linewidth lasers. Based on this, we design cm-long SiN DBRs with a bandwidth of 100-pm and tune the wavelength by 2.5 nm with a 3-fold reduction of the required power.

Mode-locked lasers find their use in a large number of applications, for instance, in spectroscopic sensing, distance measurements, and optical communication. To enable widespread use of mode-locked lasers, their on-chip integration is desired. In recent years, there have been multiple demonstrations of monolithic III-V and heterogeneous III-V-on-silicon mode-locked lasers. However, the pulse energy, noise performance, and stability of these mode-locked lasers are limited by the relatively high linear and nonlinear waveguide loss, and the high temperature sensitivity of said platforms. Here, we demonstrate a heterogeneous III-V-on-silicon-nitride (III-V-on-SiN) electrically pumped mode-locked laser. SiN’s low waveguide loss, negligible two-photon absorption at telecom wavelengths, and small thermo-optic coefficient enable low-noise mode-locked lasers with high pulse energies and excellent temperature stability. Our mode-locked laser emits at a wavelength of 1.6 μm, has a pulse repetition rate of 3 GHz, a high on-chip pulse energy of ≈2 pJ, a narrow RF linewidth of 400 Hz, and an optical linewidth <1 MHz. The SiN photonic circuits are fabricated on 200 mm silicon wafers in a CMOS pilot line and include an amorphous silicon waveguide layer for efficient coupling from the SiN to the III-V waveguide. The III-V integration is done by micro-transfer-printing, a technique that enables the transfer of thin-film devices in a massively parallel manner on a wafer scale.

We demonstrate 800 nm thick low-loss dual-layer LPCVD SiN optical waveguides with tunable profile shape to engineer modal properties. We achieved <10 dB/m loss at 1550 nm wavelength and nearly lossless vertical transitions between waveguides.

We demonstrate a III-V-on-silicon-nitride electrically pumped mode-locked laser emitting at λ = 1.6 µm with an on-chip pulse energy of approximately 2 pJ, significantly higher than on III-V-on-Si and InP photonic integration platforms.

We demonstrate the monolithic integration of CMOS-compatible ultralow capacitance hybrid III-V/Si photodetectors and test these devices up to 32Gbps NRZ. The lateral photodiodes are suitable for ultrafast optical communication without using a transimpedance amplifier.

The CMOS-compatible front-end integration of ultra-compact lateral current collection III-V/Si photodetectors on a Silicon Photonics platform is demonstrated for the first time. The novel waveguide-coupled photodiodes show sub-nA dark current, ultra-low capacitance, a high responsivity, and data transmission at 25Gbps.

CMOS-compatible III-V lasers integrated on silicon are a crucial step to reduce power consumption and cost for nextgeneration optical transceivers. Here, we demonstrate a concept to co-integrate III-V lasers into a CMOS Silicon Photonics platform, in which lasers, photonics, and electronic circuitry share the same back end of line. Based on a bonded III-V epitaxial layer stack, ultra-thin laser devices, optically pumped lasing and coupling to silicon are demonstrated. Furthermore, we present all building blocks for electrically pumped laser devices.

A silicon microlens for OAM beams collimation is, for the first time, successfully fabricated and packaged with an integrated OAM multiplexer, exploiting innovative packaging approaches. We demonstrate that such compact device does not introduce significant penalty in OAM switching experiments.

Hybrid photonic integration combines complementary advantages of different material platforms, offering superior performance and flexibility compared with monolithic approaches. This applies in particular to multi-chip concepts, where components can be individually optimized and tested. The assembly of such systems, however, requires expensive high-precision alignment and adaptation of optical mode profiles. We show that these challenges can be overcome by in situ printing of facet-attached beam-shaping elements. Our approach allows precise adaptation of vastly dissimilar mode profiles and permits alignment tolerances compatible with cost-efficient passive assembly techniques. We demonstrate a selection of beam-shaping elements at chip and fibre facets, achieving coupling efficiencies of up to 88% between edge-emitting lasers and single-mode fibres. We also realize printed free-form mirrors that simultaneously adapt beam shape and propagation direction, and we explore multi-lens systems for beam expansion. The concept paves the way to automated assembly of photonic multi-chip systems with unprecedented performance and versatility.

Realizing CMOS-compatible integrated lasers on silicon is a crucial step towards cost-efficient, high-functional optoelectronic integrated circuits (OEICs). Here, we report on a concept to embed active optical devices based on a bonded III-V epitaxial layer stack between the FEOL and BEOL of a CMOS silicon photonics chip. Ultra-shallow laser devices are realized with this concept and optically-pumped lasing, coupled to silicon is demonstrated for the first time with such a concept.