arXiv subjects

Antonino Caime

Publications and source records attributed to Antonino Caime.

2 recordsLinked to original sources

arXiv2026

In-orbit operation of a programmable quantum photonic processor

Quantum technologies promise computational capabilities beyond the reach of classical systems. A forward-looking application lies in satellite missions, which increasingly depend on onboard computing under stringent constraints on size, weight and power. Quantum photonics is particularly attractive here: photon interference can enhance the machine-learning models needed to process large onboard data volumes, at fixed hardware resources. However, harnessing this interference requires more than generating single photons, as they must remain mutually indistinguishable: a fragile condition that is hard to maintain within the technically demanding framework of a space mission, which includes a rocket launch, strong thermal drifts, and radiation. This is why quantum states of light, though already generated and transmitted in orbit for secure communication and fundamental tests, have never been used as a computational resource. Here, we report a programmable quantum photonic platform operating on a nanosatellite, processing two photons in a six-mode universal integrated circuit. By programming distinct unitaries and tuning the photons into indistinguishability, we observe two-photon interference, establishing the on-board generation, manipulation and detection of non-classical light. This extends space-based technologies towards in-orbit quantum-assisted computing, for instance local encoding of Earth-observation data, or nodes in a distributed quantum network.

quant-ph↗

arXiv2025

Laser-written reconfigurable photonic integrated circuit directly coupled to a single-photon avalanche diode array

To date, most integrated quantum photonics experiments rely on single-photon detectors operating at cryogenic temperatures coupled to photonic integrated circuits (PICs) through single-mode optical fibers. This approach presents significant challenges due to the detection complexity, as cryogenic conditions hinder the development of scalable systems. In addition, going towards fully-integrated devices or, at least, removing the optical fibers would be also advantageous to develop compact and cost-efficient solutions featuring a high number of optical modes. This work reports on the direct coupling of a PIC, fabricated by femtosecond laser writing (FLW), and a silicon single-photon avalanche diode (SPAD) array, fabricated in a custom planar technology and compatible with the operation at room temperature. The effectiveness of this solution is shown by achieving perfect coupling and a system detection efficiency as high as 41.0% at a wavelength of 561 nm, which is the highest value reported to date among both heterogeneous/hybrid integrated and directly coupled systems. We also show the robustness of the coupling to misalignments, demonstrating that costly alignment procedures are not needed. Finally, we exploit the SPAD array to characterize a reconfigurable Mach-Zehnder interferometer, i.e., the basic building block of multimode reconfigurable PICs. This solution provides a new avenue to the design and implementation of quantum photonics experiments, especially effective when compact and cost-efficient systems are needed.

physics.optics↗