This thesis reports on the development of novel techniques for the detection
and manipulation of cold gases of neutral atoms. The research presented
focusses on the implementation of a photonic waveguide chip into an atom
optics experiment. Our photonic chip consists of 12 parallel waveguides
with a 10 µm pitch and a 16 µm trench in the centre. A wire subchip underneath
the photonic chip can create magnetic fields to guide atoms into the
trench and hold them there. The electric field of the light mode propagating
through the waveguides has a 1/e radius of 2:2 µm. This small light mode
can readily be used for local measurements of the atomic density. This thesis
describes the setup of the waveguide chip experiment and gives a detailed
characterisation of the interaction between light and atoms in the trench.
Additionally, I report on a scheme for detecting atoms while minimising
the number of scattered photons for a given precision of the measurement.
We use a light beam synthesized from two frequencies tuned to either side
of the atomic resonance and detect the differential phase shift they acquire
when passing through an atomic cloud by referencing the beat between
the two frequencies to a local oscillator. Unlike most similar techniques our
beam does not contain a carrier signal and can therefore be balanced around
the atomic resonance in order to cancel the mean optical dipole force on the
atoms.