The physical realisation of a photonic quantum computer requires a reliable, fast, ondemand
source of single indistinguishable photons. A promising candidate for one of these
sources is a single dye molecule in a solid state matrix placed within the evanescent field
of a photonic waveguide.
This thesis explores the possibility of coupling of single dibenzoterrylene (DBT) molecules
in an anthracene matrix to a silicon nitride waveguide at room temperature. I first discuss
the theory by which photons from a DBT molecule can be evanescently coupled to a
ridge waveguide. I present a novel growth method to form DBT-doped anthracene crystals
which is very promising for applications to photonic devices.
I discuss the methodology and the theory of such growth. I describe the confocal
microscope I developed and used to image and characterise the emission of the single
DBT molecules embedded in these crystals. My measurements show that the molecules
are extremely stable single quantum emitters with a well-de ned polarization relative to
the crystal axes. Measurements of the saturation intensity at room temperature allow
me to estimate that a single DBT molecule could deliver at least 1012 photons before
bleaching.
This method of growth was used to deposit DBT molecules on top of a silicon nitride
ridge waveguide. The results of the coupling experiment are shown. These include confocal
images, saturation and lifetime measurements. The coupling efficiency is calculated and
compared to what was simulated. The challenges of such structures are then presented. To
tackle these challenges I deposited the molecules on top of lithium niobate and in silicon
nitride slots.
I conclude with a proposal for constructing the best photonic structure which would
guarantee an easy deposition of the molecules and high coupling efficiencies.Open Acces
