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Cristina Catalá-Lahoz

Publications and source records attributed to Cristina Catalá-Lahoz.

3 recordsLinked to original sources

High-Speed Non-Volatile Barium Titanate Field Programmable Photonic Gate Array

Programmable integrated photonics aims to replicate the versatility of field-programmable gate arrays in the optical domain. However, scaling these systems has been prevented by the high power consumption and thermal crosstalk of conventional volatile phase shifters. Here, we demonstrate the first non-volatile field-programmable photonic gate array, implemented on a hybrid silicon-barium titanate platform. Unlike traditional thermo-optic devices that require constant power to maintain a state, our device utilizes ferroelectric domain switching to provide non-volatile memory, allowing optical circuits to be programmed and retained without any holding power or electrical bias. The hexagonal waveguide mesh integrates 58 programmable unit cells and 116 actuators, achieving nanosecond-scale switching speeds of 80 nanoseconds while reducing static power consumption to negligible levels (560 nanowatts per π phase shift). To validate this platform, we configured the mesh to perform diverse signal processing functions, including tunable filtering, 4x4 linear unitary transformations, and optical routing. This work establishes non-volatile ferroelectric silicon photonics as a scalable, heat-free platform essential for the next generation of energy-efficient photonic computing.

physics.optics↗

Non-uniform programmable photonic waveguide meshes

Programmable integrated photonics has emerged as a powerful platform for implementing diverse optical functions on a single chip through software-driven reconfiguration. At the core of these processors, photonic waveguide meshes enable flexible light routing and manipulation. However, recirculating waveguide meshes are fundamentally limited by the fixed dimensions of their unit cells, constraining their spectral and temporal resolution. These limitations hinder broadband signal processing and high-precision delay-line applications. Here, we introduce the concept of non-uniform programmable waveguide meshes by incorporating defect cells into an otherwise uniform hexagonal architecture. These defect cells preserve an external hexagonal perimeter for seamless integration while embedding smaller internal subcells that modify the spectral response via the Vernier effect. By coupling cells with different optical path lengths, we achieve a free spectral range multiplication of up to tenfold, reaching 133 GHz-surpassing the capabilities of conventional silicon ring resonators. Additionally, we demonstrate a dramatic reduction in sampling times from 75 ps to 7.5 ps, enabling ultra-fast optical signal processing and high-precision delay tuning. This approach unlocks new degrees of freedom in programmable photonic circuits, offering enhanced spectral and temporal tunability. Beyond broadband signal processing, it paves the way for advanced applications in topological photonics, quantum information processing, and high-speed optical computing.

physics.optics↗

Linearization of a dual-parallel Mach-Zehnder modulator using optical carrier band processing

The linearization of a microwave photonic link based on a dual-parallel Mach-Zehnder modulator is theoretically described and experimentally demonstrated. Up to four different radio frequency tones are considered in the study, which allow us to provide a complete mathematical description of all third-order distortion terms that arise at the photodetector. Simulations show that a complete linearization is obtained by properly tuning the DC bias voltages and processing the optical carrier and. As a result, a suppression of 17 dBm is experimentally obtained for the third-order distortion terms, as well as a SDFR improvement of 3 dB. The proposed linearization method enables the simultaneous modulation of four different signals without the need of additional radio frequency components, which is desirable to its implementation in integrated optics and makes it suitable for several applications in microwave photonics.

physics.optics↗