Nano-photonics in III-V semiconductors for integrated quantum optical circuits

This thesis describes the optical spectroscopic measurements of III-V semiconductors
used to investigate a number of issues related to the development of integrated
quantum optical circuits.
The disorder-limited propagation of photons in photonic crystal waveguides in the
slow-light regime is investigated. The analysis of Fabry-Perot resonances is used
to map the mode dispersion and extract the photon localisation length. Andersonlocalised
modes are observed at high group indices, when the localisation lengths
are shorter than the waveguide lengths, consistent with the Fabry-Perot analysis.
A spin-photon interface based on two orthogonal waveguides is introduced, where
the polarisation emitted by a quantum dot is mapped to a path-encoded photon.
Operation is demonstrated by deducing the spin using the interference of in-plane
photons. A second device directly maps right and left circular polarisations to
anti-parallel waveguides, surprising for a non-chiral structure but consistent with
an off-centre dot.
Two dimensional photonic crystal cavities in GaInP and full control over the spontaneous
emission rate of InP quantum dots is demonstrated by spectrally tuning
the exciton emission energy into resonance with the fundamental cavity mode.
Fourier transform spectroscopy is used to investigate the short coherence times of
InP quantum dots in GaInP photonic crystal cavities.
Additional technological developments are also presented including a quantum
dot registration technique, electrical tuning of quantum dot emission and uniaxial
strain tuning of H1 cavity modes.