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We demonstrate an ultra-fast athermal continuous wavelength-swept III-V-on-SOI MOSCAP DFB laser with a mode-hop-free-tuning up to 10 GHz in less than 2 ns. We also propose a new method to linearize the frequency response without any pre-distortion or active feedback in the gain’s current injection ramp. Instead, we polarize the III-V gain Section under direct current injection, and we drive the hybrid MOSCAP waveguide with an AC voltage signal. By optimizing its driving frequency, we demonstrate an ultra-fast athermal triangular-shaped time-varying frequency tuning with a speed of $4\times 10 ^{4}$ PHz/s and a laser’s frequency excursion of 4 GHz.

The introduction of selective area growth (SAG) in a mature semi‐insulating buried heterostructure (SIBH) platform for the realization of photonic integrated circuits on monolithic InP has been demonstrated. A thorough determination of the relations between quantum well thickness, transition energies, and mask geometries is performed on dedicated wafers by means of extensive micro‐X‐Ray diffraction and microphotoluminescence measurements. Based on those results, SAG is used to grow, with a single epitaxy step, AlGaInAs multiple quantum wells heterostructures, to tailor the active regions of Fabry–Pérot and distributed feedback (DFB) lasers emitting in the O‐Band. SIBH DFB lasers are realized, exhibiting threshold currents < 7.2 mA (at 25 °C), and emitting over 100‐nm spectral range in the O‐Band. A novel process flow for the production of distributed feedback lasers for datacenter applications has been demonstrated based on selective area growth. The method has allowed for the coverage of the whole O‐Band at different operating points on uncooled operation and on a short production cycle. This approach is presented as a stepping stone toward the next generation of photonic integrated circuits.

In this article, we investigate the molecular beam epitaxy growth of unannealed 1.12 eV InGaAsN solar cells. The impact of the growth temperature, the As/III ratio and the bismuth used as a surfactant are reported. An in-situ curvature measurement setup enables to monitor and ensures a constant N incorporation during the InGaAsN growth. Ex-situ characterization results suggest that a high As/III ratio ensures good optoelectronic properties and that the growth temperature has a strong influence on the residual doping of the dilute nitride layer. Under AM0 > 870 nm and without antireflection coatings, our best InGaAsN solar cells exhibit Jsc and Voc values of 7.94 mA/cm2 and 0.375 V, respectively. Considering no internal reflection and no grid shading, generation up to 12 mA/cm² in a multijunction solar cell can be expected, which is the highest value ever reported for As-grown InGaAsN cells to our knowledge.

Monolithic photonic integrated circuits (PIC) transmitters using the prefixed optical phase switching concept for BPSK modulation format have been shown promising at 1.55 μm band. These devices could also be crucial for short reach connections and access networks. With this aim, we are studying basic quantum well designs for a laser and an electro‐absorption modulator switch to be integrated by selective area growth into PICs at 1.3 μm. Photocurrent measurements and band offset modeling have been performed to determine the MQW stack well‐fitted for this application. Broad area laser measurements have also been checked on these structures to verify the material lasing properties. A 6 nm thick well with low barrier seems to be the best trade‐off between absorption and shift for 1.3 μm EAM and it also gives good lasing properties.

We developed a generic photonic integration platform based on selective area growth (SAG) by metal organic vapor-phase epitaxy (MOVPE) of AlGaInAs/InP multiple quantum well (MQW) material. For efficient and predictive band gap engineering of photonic integrated circuits, different SAG zones of active and passive function heterostructures are precisely modeled and characterized. With the vapor-phase diffusion model, using numerical simulations of finite volumes, we extracted the three effective diffusion lengths of Al, Ga, and In species. In our growth conditions, these lengths were 32, 65, and 14 μm, respectively. The Kardar-Parisi-Zhang (KPZ) equation, a classic approach to describe the growing interface profile, is used. AlGaInAs MQW properties are then simulated in terms of thickness, composition, band gap, and biaxial strain variations. Highly resolved μ-photoluminescence and optical interferometer microscopy measurements confirm the validity of the band gap and thickness variations for both bulk and MQW layers. A new diffractometer, with a submillimeter X-ray spot, was used to study the structural properties of the MQW in the center of the SAG area. As an application, we present the realization and operation of full-monolithic high-speed advanced modulation format transmitters based on novel prefixed optical phase switching by fast electro-absorption modulators.

Near-transform-limited subpicosecond pulses at 1.56?μm were generated from an optically pumped InP-based vertical-external-cavity surface-emitting laser (VECSEL) passively mode-locked at 2?GHz repetition rate with a fast InGaAsNSb/GaAs semiconductor saturable absorber mirror (SESAM). The SESAM microcavity resonance was adjusted via a selective etching of phase layers specifically designed to control the magnitude of both the modulation depth and the intracavity group delay dispersion of the SESAM. Using the same VECSEL chip, we observed that the mode-locked pulse duration could be reduced from several picoseconds to less than 1?ps with a detuned resonant SESAM.

Near-transform-limited subpicosecond pulses at 1.56?μm were generated from an optically pumped InP-based vertical-external-cavity surface-emitting laser (VECSEL) passively mode-locked at 2?GHz repetition rate with a fast InGaAsNSb/GaAs semiconductor saturable absorber mirror (SESAM). The SESAM microcavity resonance was adjusted via a selective etching of phase layers specifically designed to control the magnitude of both the modulation depth and the intracavity group delay dispersion of the SESAM. Using the same VECSEL chip, we observed that the mode-locked pulse duration could be reduced from several picoseconds to less than 1?ps with a detuned resonant SESAM.

Hybrid integration of III–V materials onto silicon by wafer bonding technique is one of the mature and promising approaches to develop advanced photonic integrated devices into the silicon photonics platform (SPP). Epitaxial regrowth of III–V materials on InP thin seed layer bonded to an oxidized silicon wafer has shown its potential to extend the III–V mature multiregrowth technologies into the SPP. In the approach, an epitaxial InP layer grown on a 4 in. InP wafer is directly bonded onto a SiO2/Si 200 mm wafer. After InP substrate removal, the new template (InPoSi) is evaluated for epitaxial regrowth: an eight periods strain‐compensated AlGaInAs multiquantum wells (MQW) heterostructure surrounded by two InP cladding layers is grown by metal‐organic vapor phase epitaxy (MOVPE) simultaneously on the InPoSi substrate and on an InP substrate as a reference. For the first time, in situ reflectance and curvature measurements are carried out on InPoSi, enabling the assessment of surface roughness and thermal strain of the III–V materials during growth. High material quality is obtained as attested by X‐ray diffraction, photoluminescence, atomic force microscopy, and transmission electron microscopy. Epitaxial growth of AlGaInAs‐based multiquantum wells heterostructure on a directly bonded InP‐SiO2/Si substrate is evaluated. The thermal strain induced in the bonded membrane is assessed from in situ curvature measurement carried out during growth. Ex situ characterizations account for the high crystal quality of the structure compared to a reference grown on InP substrate.

Multijunction solar cells based on III–V compounds are one of the most effective possibilities to achieve high efficiencies for space and terrestrial applications. In this work, AlInAs:C/InP:S tunnel junctions are fabricated using MOVPE. Type‐II interface band alignment of AlInAs/InP heterostructure is ideal for increasing the photogenerated carriers tunneling. Furthermore, wide bandgaps ensure a high transmission of the incident light. The J–Vcharacteristics of the final devices show very good results in terms of tunneling peak current density (1000 A cm−2) and specific resistance at low applied bias, making them compatible for photovoltaic applications. The use of highly doped, transparent tunnel junction is necessary for the realization of efficient multijunction solar cells. In this study, a new structure lattice matched on InP and grown by MOVPE is presented. Its excellent performances make it suitable for operation under both low and high solar concentration.

Low timing jitter, sub picoseconds pulse source at 1.55 m is demonstrated by integrating a fast saturable absorber mirror (SESAM) with an optically-pumped mode-locked vertical-extended-cavity-surface emitting laser (ML-VECSEL). In such a soliton-like pulse-shaping mechanism, short pulse generation requires to control the group delay dispersion (GDD) in the cavity in order to balance the nonlinear phase shift induced by strong semiconductor gain and absorber saturation. By using selective etching technology, we controlled the SESAM optical cavity by varying from a resonant to anti-resonant configuration (which corresponds to a GDD variation from -2000fs2 to +500fs2 at 1.55 m) in the passive mode-locking cavity. Using the same VECSEL chip, we observed that the mode-locked pulse duration could be reduced from several ps to less than one ps with a resonance managed SESAM.

We report, for the first time, a direct relationship between the composition fluctuation on the ternary layer grown by atmospheric pressure metalorganic vapor-phase epitaxy (AP-MOVPE) and the pulsed character of high-vapor-pressure metalorganic (MO) flows. We show that the grwoth rates of GaAlAs and GaInAs layers, grown with trimethylgallium (TMG) and triethylgallium (TEG) sources, are of tens of Å per bubble for the methyl case and a few Å for the ethyl one.