Show simple item record

dc.contributor.advisorWang, Zheng, Ph. D.
dc.contributor.advisorLi, Elaine
dc.creatorWang, Danlu, Ph. D.
dc.date.accessioned2018-07-25T21:00:25Z
dc.date.available2018-07-25T21:00:25Z
dc.date.created2018-05
dc.date.issued2018-06-22
dc.date.submittedMay 2018
dc.identifierdoi:10.15781/T2WP9TQ94
dc.identifier.urihttp://hdl.handle.net/2152/65816
dc.description.abstractIntegrated photonics provide unique advantages in tailoring and enhancing optical forces. Recent advancements in integrated photonics have introduced many novel phenomena and exotic photonic media, such as photonic topological insulator, negative index material, photonic crystals, 2D material, and strongly-modulated time-dynamic systems. In my dissertation, I theoretically and numerically explore the novel properties and applications of optical forces in these systems. We propose guided-wave photonic pulling forces in photonic crystal waveguides. Photonic crystal waveguides offer great capability to define the mode properties, and can incorporate complex trajectories, leading to unprecedented flexibility and robustness compared to previous works in free space or in longitudinally uniform waveguides. With response theory, a virtual work approach, we establish general rules to tailor optical forces in periodic structures involved with photonic crystals: pulling forces arise from negative gradients in the phase responses of the outgoing modes, which corresponds to forward scattering on the Bloch band diagram with unit cell function corrections. We devise robust forward scattering, first, using topologically protected nonreciprocal chiral edge states, second, using backward (i.e. negative index) waves in a reciprocal system. The structures are tailored to accommodate only the necessary modes, which largely benefits the robustness. With these, we numerically demonstrate long range pulling forces on arbitrary particles through sharp corners. Our work paves the way towards sophisticated optical manipulation with single laser beam. We next explore the implication and applicability of momentum conservation in periodic media, which has been unclear due to the inhomogeneity and strong near field. We first quantify the linear momentum flux of Bloch modes under discrete translational symmetry, which is further understood from their plane wave composition. We then demonstrate through varies examples that the change in momentum flux predicts a total force distributed to both the scatterer and the media. However, one still need response theory to predict the forces on individual objects. Using response theory, we can predict more general forms of optical forces. We numerically demonstrate optical motoring effect due to singularity in the phase responses, and strong optical forces between graphene sheets due to large gradients in the phase responses. In particular, by combining the strong forces in graphene guided-wave system and the exceptional elastic properties of graphene, we can get an SBS gain that is four orders of magnitude stronger than in a silicon step-index waveguide, which may lead to smaller devices for RF signal processing.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.subjectOptomechanics
dc.subjectOptical forces
dc.subjectIntegrated photonic system
dc.subjectPhotonic crystal
dc.subjectPhotonic topological insulator
dc.titlePhase-driven optomechanics in exotic photonic media
dc.typeThesis
dc.date.updated2018-07-25T21:00:26Z
dc.contributor.committeeMemberLai, Keji
dc.contributor.committeeMemberFlorin, Ernst-Ludwig
dc.description.departmentPhysics
thesis.degree.departmentPhysics
thesis.degree.disciplinePhysics
thesis.degree.grantorThe University of Texas at Austin
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy
dc.type.materialtext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record