Programmability in femtosecond-laser-written integrated circuits is commonly achieved with the implementation of thermal phase shifters patterned from a single gold film on a trenched substrate. To increase the compactness, we propose two improvements to this technology. Firstly, we report thermal phase shifters with a photolithography process based on two different metal films. Secondly, we show a novel curved isolation trench design that allows for a significant reduction in the optical length of integrated circuits. These results pave the way toward the fabrication of femtosecond-laser-written photonic circuits with a steep increase in terms of layout complexity.
Day: July 31, 2022
Published paper in Optics Express on July 2022
We report the fabrication of alkali-metal vapor cells using femtosecond laser machining. This laser-written vapor-cell technology allows arbitrarily-shaped 3D interior volumes and has potential for integration with photonic structures and optical components. The LWVC technology may find application in miniaturized atomic quantum sensors and frequency references.
Published paper in Science Advances on July 2022
The deployment of a full-fledged quantum internet poses the challenge of finding adequate building blocks for entanglement distribution between remote quantum nodes. Here, we demonstrate a fiber-integrated quantum memory entangled with a photon at telecommunication wavelength. Our results feature orders-of-magnitude advances in terms of storage time and efficiency for integrated storage of light-matter entanglement and constitute a substantial step forward toward quantum networks using integrated devices.