Mode Competition in Dual-Mode Quantum Dots Semiconductor Microlaser

This paper describes the modeling of quantum dots lasers with the aim of assessing the conditions for stable cw dual-mode operation when the mode separation lies in the THz range. Several possible models suited for InAs quantum dots in InP barriers are analytically evaluated, in particular quantum dots electrically coupled through a direct exchange of excitation by the wetting layer or quantum dots optically coupled through the homogeneous broadening of their optical gain. A stable dual-mode regime is shown possible in all cases when quantum dots are used as active layer whereas a gain medium of quantum well or bulk type inevitably leads to bistable behavior. The choice of a quantum dots gain medium perfectly matched the production of dual-mode lasers devoted to THz generation by photomixing.Comment: First draft of a paper submitted to Phys Rev A. This version includes an extended discussion about dual-mode lasers and recall some known results about stability. Extended bibliograph

Analyse du processus de formation de la barrière or-silicium

Nous comparons les caractéristiques courant-tension sous éclairement de diodes Schottky or-silicium à des courbes théoriques de structures MIS. Nous montrons que l'évolution dans le temps de ces caractéristiques est due à la neutralisation d'une charge fixe positive, située à l'interface métal-semiconducteur, par l'oxygène de l'air qui diffuse à travers le contact métallique et qui se comporte en piège à électrons du semiconducteur

Nano-meter scale heterogeneous III-V semiconductor-silicon photonic integration

It is pointed out that the fully recognised and ever growing need for a combination of photonic and electronic functionalities could be made fully effective by the heterogeneous integration of active III-V semiconductor/passive silicon photonics and silicon microelectronics. It is shown that the inevitable scaling down to nano-meter range of photonic integration requested by the necessary matching to microelectronics is made possible by the heterogeneous association of IIIV semiconductor and silicon membranes including high index contrast and nano-meter scale structuring. It is emphasized that these membrane photonic nanostructures can be considered as the absolute must on the track to the ultimate confinement of photons which is highly desired in the prospect of the development of Micro-Nano-Photonic devices and systems. Examples of devices and systems along this approach are presented (micro-laser/micro-guide integration, active devices with very low threshold,...)

Design and investigation of surface addressable Photonic Crystal cavity confined band edge modes for quantum photonic devices

We propose to use a localized G-point slow Bloch mode in a 2D-Photonic Crystal (PC) membrane to realize an efficient surface emitting source. This device can be used as a quantum photonic device, e.g. a single photon source. The physical mechanisms to increase the Q/V factor and to improve the directivity of the PC microcavity rely on a fine tuning of the geometry in the three directions of space. The PC lateral mirrors are first engineered in order to optimize photons confinement. Then, the effect of a Bragg mirror below the 2DPC membrane is investigated in terms of out-of-plane leakages and far field emission pattern. This photonic heterostructure allows for a strong lateral confinement of photons, with a modal volume of a few (λ/n)3 and a Purcell factor up to 80, as calculated by two different numerical methods. We finally discuss the efficiency of the single photon source for different collection set-up. © 2011 Optical Society of America

Microlasers based on effective index confined slow light modes in photonic crystal waveguides

We present the design, theory and experimental implementation of a low modal volume microlaser based on a line-defect 2D-photonic crystal waveguide. The lateral confinement of low-group velocity modes is controlled by the post-processing of 1 to 3μm wide PMMA strips on top of two dimensional photonic crystal waveguides. Modal volume around 1.3 (λ/n)3can be achieved using this scheme. We use this concept to fabricate microlaser devices from an InP-based heterostructure including InAs0.65P0.35quantum wells emitting around 1550nm and bonded onto a fused silica wafer. We observe stable, room-temperature laser operation with an effective lasing threshold around 0.5mW. © 2008 Optical Society of America

Mechanical relaxation of strained semiconducting stripes: Influence on optoelectronic properties

International audienc

Room-temperature InAs/InP Quantum Dots laser operation based on heterogeneous “2.5 D” Photonic Crystal

International audienceThe authors report on the design, fabrication and operation of heterogeneous and compact "2.5 D" Photonic Crystal microlaser with a single plane of InAs quantum dots as gain medium. The high quality factor photonic structures are tailored for vertical emission. The devices consist of a top two-dimensional InP Photonic Crystal Slab, a SiO 2 bonding layer, and a bottom high index contrast Si/SiO 2 Bragg mirror deposited on a Si wafer. Despite the fact that no more than about 5% of the quantum dots distribution effectively contribute to the modal gain, room-temperature lasing operation, around 1.5µm, was achieved by photopumping. A low effective threshold, on the order of 350µW, and a spontaneous emission factor, over 0.13, could be deduced from experiments

Observation of photoluminescence from InAs surface quantum wells grown on InP(100) by molecular beam epitaxy

Photoluminescence (PL) measurements are presented for thin epitaxial layers of InAs, 2.5 Å<d <36 Å, grown on InP(100) by molecular beam epitaxy. The combination of efficient carrier capture and PL redshift with increasing InAs thickness clearly indicate the formation of InAs quantum wells on the InP surface. Data are also presented for InAs/InP structures capped with strained layers of either GaAs or In0.5 Al0.5 As. Since radiative recombination within the InAs layers can be distinguished from PL arising from both bulk and surface defects, this system allows us to monitor the quality of both the InAs/InP and InAs/air interfaces via their influence on the InAs quantum well luminescence