Information, communication and sensing lies at the heart of the social and economic dynamics; in this context, quantum physics has recently offered radically new avenues to treat and transmit information in a more secure and efficient way than what we can do with classical systems (exchange of sensitive data, enhancement of computing capabilities, increased precision in measurements). In parallel with fundamental researches aiming to test the foundations and limits of quantum information science, we are witnessing today to the maturation of quantum information technologies among which photonics is playing a central role. Currently, one of the main technological challenge towards large-scale applications is the miniaturization of different building blocks on a single chip operating at room temperature. In this respect, semiconductor materials are ideal to achieve extremely compact and massively parallel devices. This project is focused on the demonstration of electrically driven integrated quantum photonic circuits including photon pair generation and manipulation, working at room temperature and telecom wavelength. The starting point is contituted by two III-V semiconductor sources of nonclassical states of light recently demonstrated within the consortium: an electrically injected source of photon pairs (F. Boitier et al. to appear in Phys. Rev. Lett. Issue of May 9 2014), and a ridge microcavity emitting counterpropagating entangled photons (A. Orieux et al. Phys. Rev. Lett. 110, 160502 (2013). SemiQuantRoom will have 3 main objectives: the optimization of these sources, the characterization of the original quantum properties of the emitted bi-photon states and the monolithic or hybrid (III-V/Si) integration of these devices with quantum photonic circuits. This choice combines the advantages of two material platforms. On one hand, III-V semiconductors do afford excellent optical properties and, thanks to their direct bandgap, present en evident interest for electrically driven devices. Recent achievements in Si photonics has shown that SOS and SOI circuits are promising platforms for optical components offering the added value of compatibility with the mature and high-quality CMOS technology. The project will benefit of the complementary and renowned expertise of the three partners: The Laboratory Quantum Phenomena and Materials (LMPQ) will contribute with its know-how in design, fabrication and characterization of III-V quantum photonic devices and quantum optics theory (notably characterization and manipulation of entanglement). The Laboratory of Photonics and Nanostructures is a node of the National Network of Nanotechnology Facilities. It will contribute with its expertise in high quality GaAs/AlAs microcavities growth by molecular beam epitaxy, in dielectric multilayer deposition for high anti-reflective coatings and adhesive bonding of III-V nanolasers onto a silicon waveguide circuitry. The ultrafast quantum optics and optical metrology group from Oxford University has broad expertise concerning the generation and manipulation of pulsed quantum light and its application to quantum information science. The group is one of the world leaders in the development of integrated photonic technologies for scalable quantum networks and will provide expertise for designing and implementing quantum protocols - in particular, primitives for information processing such as quantum teleportation and quantum gates, as well as novel sensors based on quantum-enhanced phase measurements. The expected results of SemiQuantRoom have the potential to become a new generation of devices for quantum information, communication and metrology and open the way towards complete quantum optics lab on a chip, where lasers, linear and nonlinear elements as well as detectors can all be built in one package.

The Optical Parametric Oscillator (OPO), one of today’s most known optical devices, can be functionally defined as a widely tunable coherent source. Like the laser, it is based on the resonant feedback provided to an optical amplifier by a cavity. Unlike the laser, it relies on parametric amplification instead of stimulated emission and population inversion. This project aims at demonstrating the first electrically pumped OPO. Such result will constitute a major scientific breakthrough because at variance with the laser, whose heterostructure diode version has spurred the field of photonics, the quest for an electrically injected monolithic OPO is still open half a century after the original demonstration of the OPO. Today OPOs, pumped by conventional lasers, are available under very different time, spectral and power formats. Large segments of the related technology are at a mature stage for several industrial, military, health and environmental applications, with new commercial products being launched on the market at a growing rate. However, most of this market is still very connected to research mainly because of the limited portability of the current OPOs. Such limitation might be overcome by the diode-OPO (DOPO) to be developed in this project, which will emit in the near to mid infrared (1.5-3.5 µm) under CW operation at room temperature. The DOPO source that we will develop relies on intracavity parametric generation in a deeply etched narrow-stripe QD laser diode. Here the main advantage of using QDs is related to their ability to trap charge carriers and quench diffusion toward non-radiative recombination centers. For lasers, this effect enables the fabrication of deeply etched narrow-stripe (few µm) laser diodes with threshold currents comparable to those of broad area devices. This is the key for the demonstration of a DOPO, since the width of such narrow deeply etched ridge waveguides constitutes a very efficient degree of freedom to ensure phase matching in diode OPOs. In the key-enabling-technology field of photonics, the demonstration of a diode OPO would be a disruptive achievement for: 1) the telecom range, where the mode-hopping-free tunability of existing DFB and DBR lasers constitutes a strong limitation, and where there is presently a strong interest in largely tunable and wavelength-selectable sources, mainly for access networks; and 2) the eye-safe 2-3.5 µm window, which is widely used for civilian applications including gas sensing, security and medical applications, as well as for military applications. The availability of integrated components for this spectral range remains extremely limited, the devices operating in this range being largely restricted to stand-alone and narrow-band sources. The availability of diode-OPOs would induce a true revolution in both these fields due to their compactness, wide tunability, energetic efficiency and low cost, with a possible impact on sensors for environmental or medical monitoring. Concerning industrial property and technological transfer, the very same reasons behind the exceptional performance of the laser diode (compactness, low cost, low-power operation) would also boost the patent and industrial perspectives of the first DOPO. The delivered device and technology will allow the creation of IP, as already highlighted by a first patent jointly filed by INAC and MPQ while preparing this project. The competences of these partners in quantum-dot physics and nonlinear photonics are completed by a third research group, III-V Lab, a leader in the semiconductor photonic technology. Finally the presence, through III-V Lab, of the industrial partners Thales and Alcatel-Lucent, with their excellent track records in developing and bringing to the market novel advanced optoelectronic products, crucially strengthens the valorization perspectives for the DOPO project.