Solid state physics, chemistry and nanosciences - Optics - Laser optics

Study of MEMS / NEMS devices on silicon photonics circuits

These several last years technological advances in the field of silicon micromachining have initiated the industrial growth of Microsystems / Nanosystems Electro Mechanical (M / NEMS) for fabricating sensors or actuators. In the field of NEMS with sub-micron sizes the properties allow for targeting applications in biomedical or biochemical analyses. It has been demonstrated that these nano mass (or force) sensors reach resolutions of the order of zepto gram (10-21g) or pico Newton, hence allowing early diagnosis of certain cancers. Transduction schemes of these systems are currently based on electrical principles. Many teams have nevertheless shown that photonics could operate and detect tiny displacement (fm). This hybrid technology, photonic circuit associated with M / NEMS potentially offers a significant improvement compared to electrical transduction. The purpose of the thesis consists of developing opto-electromechanical model with analytical approach and numerical simulations as well. First different transduction approaches will be studied. In particular the performance of optical detection will be compared to nanoscale electrical detection features. The comparison will be based on objective criteria (sensitivity, noise, crowding) for designing original optomechanical structures. The student will also develop the bench for optical and mechanical characterizations. Measurements on existing components (photonic circuit & NEMS) will allow to better understand the design constrains. This thesis has two parts that are the simulation and characterization. Both parts will run in parallel.

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Département : Département Composants Silicium (LETI) Laboratory : Laboratoire Composants Micro-Capteurs Start Date : 01-10-2013 ECA Code : SL-DRT-13-0088 Contact : guillaume.jourdan@cea.fr

Co-design of image sensor architectures and advanced optical functions for novel acquisition of images

The micro-mirrors in video projectors, microlenses of plenoptic cameras, or Spatial Light Modulators (SLM) are some examples of the micro and nanotechnologies contribution to novel optical functions, which constitute breakthrough with respect to the conventional optics. In addition to new features, these processes often allow a low-cost, yet extremely accurate manufacturing, making them compatible with consumer applications and/or with high volume production. However, the acquisition of the images or the light signals is realized with standard image sensors, which limit the fields of applications. Based on Léti's works in smart CMOS image sensors, the objective of the thesis consists in proposing original images sensors' architecture, as well as novel processing, to be integrated in advanced CMOS technology. This combination will allow the emergence of novel functions and breakthrough in terms of performances.

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Département : Département Architectures Conception et Logiciels Embarqués (LIST-LETI) Laboratory : Laboratoire Circuits Intégrés, Intelligents pour l'Image Start Date : 01-10-2013 ECA Code : SL-DRT-13-0520 Contact : laurent.alacoque@cea.fr