You are warmly invited to attend the next seminar of the QST Seminar Series 2024/2025 in Naples.

Speaker: Andrea Crespi, Dipartimento di Fisica – Politecnico di Milano and Istituto di Fotonica e Nanotecnologie – Consiglio Nazionale delle Ricerche (IFN-CNR)

Title: Reconfigurable femtosecond-laser-written interferometers for quantum photonics

Time/Location: Thursday, Jul 3, 2025 at 15:00 in Aula 0M04 - Department of Physics - Federico II

Online: Online participation via MS Teams link. IMPORTANT: In case your access is denied, log out from your institutional account and open MS Teams in your web browser.

Abstract

The adoption of an integrated waveguide platform has been a key passage that allowed quantum photonics to reach many important experimental milestones in the recent years. Indeed, the compact and monolithic construction of waveguide circuits provides incomparable interferometric stability and makes it possible to condense optical setups of unprecedented complexity in a small footprint, thus paving the way to applications in quantum simulation, metrology and communications. In this context, the femtosecond laser micromachining technology has played an important role. As a non-lithographic fabrication method, it allows for rapid prototyping of new circuit designs, and offers unique three-dimensional capabilities. We will discuss recent results in the realization of high-complexity interferometric circuits written with femtosecond lasers, which can be dynamically reconfigured via thermo-optic phase shifters. Three-dimensional microstructuring of the substrate - enabled by our femtosecond laser micromachining technology - has made it possible to combine high-fidelity circuit operation with remarkable energy efficiency, positioning our devices at the state of the art compared to more conventional approaches. Additionally, we will present new prospects for circuit actuation based on the elasto-optic effect, which enables phase modulation at frequencies reaching into the megahertz range.

Past and upcoming seminars are posted on our website