Group seminar at MPQ and Zoom: Optical Quantum Memories using femtosecond laser micromachining

Julien Chénede, Milan
Group seminar at MPQ lecture hall and Zoom
Thursday, July 6th, 9:00am (MEZ)

Abstract:
Optical quantum memories are crucial devices for the development of
photonic quantum technologies, as they allow synchronizing different
quantum processes, which very often take place in a probabilistic
fashion. To take full advantage of the photon storage functionality in
useful technological scenarios, quantum memories must be moved from
current bulk implementations to integrated miniaturized optical chips.
Among the different strategies pursued in this direction, a very
promising one relies in the inscription of optical waveguides in rare
earth doped transparent dielectrics via femtosecond laser irradiation,
because this technique allows to preserve the coherence properties of
the substrates while producing high quality guiding structures. Very
encouraging preliminary results have been demonstrated in this field
in recent years, however the experimental road towards reliable,
long-lived, and highly efficient integrated quantum memories is still
long.

To achieve this result, I will talk about:
- Optimize the waveguide inscription. The completion of this task will
require exploring novel irradiation regimes and performing waveguide
writing.
- Interfacing crystal waveguides with glass waveguides fabricated by femtosecond laser micromachining.
- Fabrication of a hybrid photonic chip containing multiple integrated
quantum memories and interfaced with a glass chip for efficient
waveguide addressing with standard fiber arrays.