Depuis une vingtaine d’années, l’optique bénéficie des avancées considérables de la microélectronique.Ainsi, il est maintenant possible de produire, guider, confiner ou encore ralentirla lumière sur puce à une échelle sub-longueur d’onde. Dans cette thèse, nous étudions de telscomposants par l’intermédiaire d’un microscope en champ proche optique (SNOM).La première partie présente une vision d’ensemble de la situation actuelle en nanophotoniqueintégrée sur substrat diélectrique. Elle expose plusieurs enjeux et faits marquants récents dansce domaine. Elle introduit également le principe physique et le fonctionnement d’un SNOMdans les grandes lignes.La seconde partie est consacrée à la microscopie en champ proche optique d’un point devue instrumental. Après une analyse physique, nous détaillons le montage de notre propremicroscope sur le banc de caractérisation optique du laboratoire, avant d’analyser la formationdes images optiques obtenues avec cette technique.La troisième partie concerne l’étude de guides d’onde couplés en Silicium sur isolant (SOI),dans lesquels s’intègrent des nano-cavités optiques. Les phénomènes de couplage par recouvrementde champs évanescents sont étudiés numériquement et analytiquement. L’analyse de cesstructures grâce au SNOM nous a permis d’une part de vérifier la validité de ces modèles, etd’autre part d’observer directement le guidage et le confinement de la lumière dans un milieude faible indice de réfraction. Nous montrons cependant que ces résultats restent très sensiblesaux aléas de fabrication. Enfin, nous mettons en évidence grâce au SNOM et à des mesuresspectrales que la description de structures de N cavités juxtaposées peut être approchée par lathéorie des modes couplés. / Since the end of the XXth century, optics benefits from significant breakthrough comingfrom the micro-electronic technologies. It is thus now possible to produce, guide, slow downor even trap light on a chip at a sub-wavelength scale. In this thesis, we study such opticalcomponents thanks to a Scanning Near-Field Optical Microscope (SNOM).The first part exposes an overall view of the current situation in the field of dielectricsubstrate integrated nanophotonics. Some of the recent outstanding issues and results are hereintroduced, as well as the general principle and the necessary tools to operate a SNOM.The second part is dedicated to optical near-field microscopy, technically speaking. Thephysical rules are here developed. Then we detail the instrumental set up of our own SNOMon our optical characterization bench. We end by analysing the optical images formation witha SNOM.The third part bears upon the study of Silicon-on-Insulator (SOI) coupled waveguides whereoptical nano-cavities could be inserted, by resorting to the previously implemented SNOM.Overlapping evanescent fields induced coupling phenomena are numerically and analyticallystudied. The use of the SNOM allowed us here to check the validity of our models. Besides,we have directly observed thanks to this instrument the guiding and confinement of light ina low refractive index media. However, we show that this phenomenon is highly subjected tofabrication uncertainties. Finally, we use the SNOM and spectral measurements in order todemonstrate that systems of N coupled nanocavities could be described with a simple coupledmodes model.

Vertically rolled-up microcavities are fabricated using differentially strained nanomembranes by employing rate and temperature gradients during electron beam evaporation of SiO2. The geometry of the rolled-up tubes is defined by a photo-lithographically patterned polymer sacrificial layer beneath the SiO2 layers that is dissolved to start the rolling. Rolled-up tubes support resonances formed by constructive interference of light propagating along the circumference. Optical studies are performed in the visible spectral range using a micro-photoluminescence (µPL) setup to excite and detect optical modes. Record high quality factors (Q factors) of 5400 for rolled-up resonators probed in PL-emission mode are found and their limits are theoretically investigated. Axial modes can also be supported when an increased winding number in the center is realized by appropriate pattern designs. In addition, higher order radial modes can be confined when atomic layer deposition (ALD) coatings are applied. Both types of modes are identified using polarization and spatially resolved µPL maps. Evanescent-wave coupling by tapered fibers and tubes on substrates is the second method used to study light confinement and to demonstrate frequency filtering in ALD coated rolled-up microcavities. Scans are performed by monitoring light from a tunable laser in the range of 1520-1570 nm after transmission through the tapered fiber. Dips in the spectrum are found and attributed to fundamental and axial resonant modes. Moreover, by coupling two tapered fibers to a lifted rolled-up microcavity, a four-port add-drop filter is demonstrated as a future component for vertical resonant light transfer in on-chip optical networks. Simulations show that the subwavelength tube wall thickness limits the Q factor at infrared wavelengths and ALD coatings are necessary to enhance the light confinement. After coating, two linear polarization states are found in experiment and fundamental and axial modes can be selectively excited by coupling the fiber to different positions along the tube axis. Spatially and polarization resolved transmission maps reveal a polarization dependent axial mode distribution which is verified theoretically. The results of this thesis are important for lab-on-chip applications where rolled-up microcavities are employed as high resolution optofluidic sensors as well as for future uses as waveguide coupled components in three-dimensional multi-level optical data processing units to provide resonant interlayer signal transfer.

Vertically rolled-up microcavities are fabricated using differentially strained nanomembranes by employing rate and temperature gradients during electron beam evaporation of SiO2. The geometry of the rolled-up tubes is defined by a photo-lithographically patterned polymer sacrificial layer beneath the SiO2 layers that is dissolved to start the rolling. Rolled-up tubes support resonances formed by constructive interference of light propagating along the circumference. Optical studies are performed in the visible spectral range using a micro-photoluminescence (µPL) setup to excite and detect optical modes. Record high quality factors (Q factors) of 5400 for rolled-up resonators probed in PL-emission mode are found and their limits are theoretically investigated. Axial modes can also be supported when an increased winding number in the center is realized by appropriate pattern designs. In addition, higher order radial modes can be confined when atomic layer deposition (ALD) coatings are applied. Both types of modes are identified using polarization and spatially resolved µPL maps. Evanescent-wave coupling by tapered fibers and tubes on substrates is the second method used to study light confinement and to demonstrate frequency filtering in ALD coated rolled-up microcavities. Scans are performed by monitoring light from a tunable laser in the range of 1520-1570 nm after transmission through the tapered fiber. Dips in the spectrum are found and attributed to fundamental and axial resonant modes. Moreover, by coupling two tapered fibers to a lifted rolled-up microcavity, a four-port add-drop filter is demonstrated as a future component for vertical resonant light transfer in on-chip optical networks. Simulations show that the subwavelength tube wall thickness limits the Q factor at infrared wavelengths and ALD coatings are necessary to enhance the light confinement. After coating, two linear polarization states are found in experiment and fundamental and axial modes can be selectively excited by coupling the fiber to different positions along the tube axis. Spatially and polarization resolved transmission maps reveal a polarization dependent axial mode distribution which is verified theoretically. The results of this thesis are important for lab-on-chip applications where rolled-up microcavities are employed as high resolution optofluidic sensors as well as for future uses as waveguide coupled components in three-dimensional multi-level optical data processing units to provide resonant interlayer signal transfer.