Abstract:
A fast, low-loss optical switch would be a powerful tool for photonic quantum technologies, allowing the implementation of, for example, rapid logical gates, loop memories, and efficient multiplexing of heralded single photon sources. The integration of such a switch into waveguides such as optical fibres, promises an avenue to future scalability, and integration with existing fibre optic infrastructure. Here I present demonstration of such switching achieved in bulk optics by means of a two-photon transition in rubidium. The presence of a strong control field can modulate the phase or spatial mode of a weak signal field, with low loss (1dB) and short timescales (100MHz) with the prospect of improvement via micro-cavity enhancement. I also demonstrate progress towards integration of rubidium vapour cells into optical fibres, for a fully connectorised switch.