Giacomo Ciani

Professore associato confermato

FIS/01

Address: VIA F. MARZOLO, 8 - PADOVA . . .

Phone: 049 827 7036

E-mail: giacomo.ciani@unipd.it

Research Area

Gravitational wave detectors, tehrmal noise in mechanical systems, precision metrology, laser optics, quantum optics.

Thesis proposals

Together with the Padova-Trento VIRGO experimental group, I'm carrying out a research program aimed at improving the performance of the Virgo detector and developing technologies and techniques for the next generation of gravitational wave observatories. My main research areas are precision metrology, thermal noise, laser and quantum optics. Working in our lab generally involves acquiring one or more complementary experimental skills including electronics, vacuum systems, digital data acquisition systems, mechanical filters and data analysis techniques.
We are currently engaged in several research projects, each offering multiple opportunities for a thesis. If you are interested, please feel free to contact me so we can discuss available topics.

--> Adaptive laser-cavity mode-mismatch sensing and compensation for Gravitational Wave detectors
With the introduction of quantum optics techniques to beat the standard quantum limit, the reduction of optical losses in modern gravitational wave detectors has gained high priority. A key contributor to the optical losses is the so called mode mismatch, i.e. the imperfect matching between the spatial characteristic of a laser beam and what is required by the optical resonator it is coupled to. To solve this problem, we are developing innovative optical sensors and actuators based on electro-optical, thermo-refractive and photo-elastic effects. The project involves experimental activity as well as numerical simulations and analytical studies.

--> Thermal noise in solids out of thermodynamic equilibrium
Thermal noise in mechanical systems arises as a random vibration due to the thermal energy associated to each degree of freedom because of the equipartition theorem. It is a limiting factor to the sensitivity of many high precision experiments, including gravitational wave detectors, where it manifest in the motion of the suspensions used to isolate the mirrors from ground vibration as well as in the motion of the mirrors' surface. While the theory of thermal noise in condition of thermodynamic equilibrium is well understood and experimentally verified, we have poor knowledge on how to model it in systems out of equilibrium (i.e. in the presence of thermal gradients and heat fluxes), which more accurately describes the situation of real experiments. Experimental evidence is scarce, but suggests the possibility of a significant deviation from thermal noise levels predicted at equilibrium, which would have important consequences on the design and performance of fundamental physics experiments. We are running an experiment to investigate thermal noise in the presence of thermal gradients in a macroscopic oscillator whose motion is monitored by an interferometric detector. The experiment involves laser optics, vacuum systems, mechanical filters, electronics, data acquisition and sophisticated data analysis techniques.