Micro / nano optoelectronics
The research activities, grouped in this department, correspond to studies on advanced components in the fields of micro and nanoelectronics, optoelectronics and photonics. Today, we are still far from reaching the technological limitations concerning the dimensions, the diversity of materials and architectures but also the aspects of co-integration in general. In addition, this research sector is in the midst of a mutation phase where the different disciplines (electronics, optics, electromagnetism, chemistry, biology) are merging to generate new advances. These actions, resolutely oriented towards the medium and long term, are perfectly in line with national and European strategic and economic criteria. Indeed, all of this work is supported by national (ANR PNANO, TELECOM) and European (FP6&7, ESA....) research programs.
For micro and nanoelectronics, the main objectives revolve around new technological advances, such as nano-components or organic electronics, and the rise in frequency by targeting low noise (low noise amplification, detection...) or power (power amplification, generation....) criteria. The studies concern the development and optimization of technological processes, simulations and physical and electrical characterizations. Devices based on III-V materials are strongly represented in this research axis, however specific actions are carried out around alternative Silicon technologies. In this field of micro- and nano-technologies, internationally recognized advances have been made in the field of artificial materials (metamaterials) and their microwave, submillimeter and optical applications. The two main technological approaches are addressed in these activities: one consists in reaching nanometric dimensions ('top-down'); the other, the assembly of nano-objects ('bottom-up'). This last category corresponds to the realization of high frequency transistors based on carbon nanotubes or the growth of silicon wires (or film) in dielectric nanocavities.
For optoelectronics, the actions are mainly around the realization of functions encountered in integrated optics / optoelectronics dedicated to fiber communications: photodetection, switching and laser emission. They aim at new declinations of these functions applied to the field of microwave optics, thus combining the transport/processing of microwave signals by optical means: specific opto-hyperfrequency transducers, fast integrated switches. The wavelengths are then those of optical telecommunications, the design criteria such as speed, low noise, high power, low consumption, low optical losses, ....., are then taken into account according to the envisaged application. The wavelength range has also been extended to the far infrared by the study of quantum cascade lasers and photomixing phenomena in an ultrafast photodetector and in the X-UV range from wide band gap materials. All these actions must be able to take advantage of the efforts devoted to optical nanotechnology based on photonic crystals, metamaterials, or microguides which is developed in parallel and which confers new aspects of compactness or efficiency to these devices. An action has also been initiated on the optoelectronic generation of terahertz frequencies (THz). The chosen approach is based on ultra-fast photodetectors associated with antennas. Frequency and time characterization techniques are also developed in this frequency range.