Athermal Optical Devices Used For Manipulation Of Nanoparticles

Since discovered in 1970,optical tweezer has attracted widespread attention and has been utilized for many applications in physics and biochemistry,benefiting from its advantages of being non-contact and causing low damage to the trapped object.With the development of integrated optics,it becomes an attractive goal to obtain smaller optical tweezers.By proper design of integrated optics devices,such as optical waveguides and resonators,micron-sized and nano-sized objects can be manipulated.Nanodiamond has advantages of being solid-state and the ability of working in room-temperature,which make it become a preferable choice in materials of single photon sources.In this thesis,by using a novel optical waveguide,we study manipulation of the nanodiamond and show that the particle can be trapped into the slot of a slotted waveguide,which can greatly increase the coupling efficiency of nanodiamonds.For resonance-enhanced emission of single photons,we consider placing trapped nanodiamonds into micro-resonators.Micro-ring resonators have been widely used in optical devices due to a high quality factor and resonance enhancement effect.However,resonance wavelength is sensitive to a change of ambient temperature.During the working process of integrated chips,the local temperature of optical devices increases,and this makes resonators unusable.There are already a few approaches to realize athermal optical devices.However,existing athermal optical devices are not able to realize temperature-insensitive effect in a wide wavelength range.Here,we propose a method to realize broadband athermal resonators,which can potentially enable the temperature insensitivity of micro-ring resonators over a wide spectral range.To solve the problem that micro-resonators have a high propagation loss in mid-infrared,we propose using TE₁₀ mode in the pedestal waveguide,which reduces the propagation loss by almost two orders of magnitude compared to the conventional strip waveguide.This low-loss waveguide using the TE₁₀ mode can serve as the backbone of deep mid-infrared photonic systems for bio-chemical sensing,microscopy,and other applications.