SlowBloch mode nanotweezers
type: Dataset
description: This thesis aims at improving the efficiency of conventional optical tweezers (cOT). They allow to manipulate objects with dimension from a few tens of nanometer to a few tens of micrometers with a high accuracy and without contact. This has numerous applications in biophysics and colloidal science. This thesis investigates a new approach for optical nanotweezers. It uses a photonic crystal (PC) cavity which generates a slow Bloch mode. This cavity can be effectively and easily excited with a Gaussian beam at the normal incidence. Contrarily to cOT, objective with a small numerical aperture can be used. The expected performances in terms of trapping go well beyond the diffraction limit of cOT. This work demonstrates experimentally the efficacy of approach. This thesis is divided in two main sections. First, we had to set up an experimental bench to carry out to our study. We built the optical bench interface instruments and develop programs to analyze the data. Two essential elements have been considered: - The development of the optical system allowing the excitation of the photonics nanostructure. - The design an imaging system to track nanoparticles. Second, we have focus on the demonstration of the optical trapping. We started by with a low Q factor (few hundred) cavity. Trapping efficiency of an order of magnitude higher than cOT has been demonstrated. Then, we have explored a new king of PC cavity based on double period structure. We show that thanks to this approach high Q factor of several thousand are easily reached. With this structure, we managed to trap 250nm polystyrene beads, with an optical power of the order of a milliwatt. A deep analysis of the nanoparticle trajectories allowed us to find a slow Bloch mode signature.
identifier: NNT: 2012ISAL0113
issued: 2026-05-10T13:36:06.575305
language: fr
modified: 2026-05-10T13:36:06.575310
contact point: Organization
  fn: CCSD
keyword: cristaux-photoniques
keyword: electronics
keyword: electronique
keyword: faisceau-gaussien
keyword: fdtd
keyword: fdtd---finite-difference-time-domain---method
keyword: flurescence
keyword: force-optique
keyword: infoeu-reposemanticsdoctoralthesis
keyword: microreflectivity
keyword: microreflexivite
keyword: microscopie
keyword: microscopy
keyword: microtransmission
keyword: microtransmitivity
keyword: mode-de-bloch-lent
keyword: nano-electronics
keyword: nano-electronique
keyword: nano-pinces
keyword: nano-tweezers
keyword: nanoparticle
keyword: nanoparticule
keyword: optical-trapping
keyword: optical-tweezers
keyword: photonics-crystal
keyword: pinces-optiques
keyword: slow-bloch-mode
keyword: spiotherengineering-sciences-physicsother
keyword: theses
landing page: https://theses.hal.science/tel-00838792

SlowBloch mode nanotweezers
type: Distribution
format: HTML
issued: 2026-05-10T13:36:06.618139
modified: 2026-05-10T13:36:06.534564
access URL: https://theses.hal.science/tel-00838792

test_moissonnage_selune
type: Agent