ESQ PostDoc

Stefan PUTZ

Integrated Photonic Microcavity Devices for Cooling and Detection of Nano Particles

My proposed research within the ESQ center is to create an optical microcavity platform which will serve in a cooling stage of a new particle source for high-mass matter-wave interferometry at the boundary between quantum and classical mechanics. A key requirement on the way towards this goal is the trapping, cooling and detection of nanoparticles. All this is done most efficiently in cavities with small mode volume, ensuring the highest coupling strength.

Recent progress in micromachining of silicon micromirrors has enabled unprecedentedly high finesse values about 500,000 with mode volumes smaller than 100 fL at wavelengths of 1550 nm. This shows great promise for the implementation of cavity cooling of nanoparticles. Efficient, sideband-resolved cooling of particles up to 107 amu to sub-millikelvin temperatures is within reach and shall become the basis for advanced matter-wave interferometry in regimes that had remained unreached hitherto.

At the same time, we strive to push the detection limit towards smaller particles. This will serve in novel ultra-sensitive sensors with possible industrial applications. Our silicon microcavity technology is also of interest for photonic quantum technologies, where quantum efficiencies of single photon sources could be boosted by microcavities due to exceptionally high cooperativity values. My work will build on the successful collaboration between the Arndt group and the Trupke team.

I will enable the envisaged applications by pushing the technology towards microcavities that are one order of magnitude smaller, while increasing the achievable finesse beyond one million.



ESQ office
Austrian Academy of Sciences (ÖAW)
Mag.ª Isabelle Walters
Boltzmanngasse 5
1090 Vienna