arXiv subjects

Antonio Consoli

Publications and source records attributed to Antonio Consoli.

4 recordsLinked to original sources

arXiv2025

Rough Fabry-Perot cavity: a vastly multi-scale numerical problem

A commercial Fabry-Perot laser diode is characterized by highly disproportionate dimensions, which poses a significant numerical challenge, even for state-of-the-art tools. This challenge is exacerbated when one of the cavity mirrors is rough-ened, as is the case when fabricating random laser diodes. Such a system involves length scales from several hundred mi-crometres (length) to a few nanometres (roughness) all of which are relevant when studying optical properties in the visi-ble. While involving an extreme range of dimensions, these cavities cannot be treated through statistical approaches such as those used with self-similar fractal structures known to show well-studied properties. Here we deploy numerical meth-ods to compute cavity modes and show how random corrugations of the Fabry-Perot cavity wall affect statistical proper-ties of their spectral features. Our study constitutes a necessary first step in developing technologically essential devices for photonic computation and efficient speckle-free illumination.

physics.optics↗

arXiv2025

Feedback suppression in 405 nm superluminescent diodes via engineered scattering

Superluminescent diodes are promising devices for applications in which low coherence, high efficiency, small foot-print and good optoelectronic integration are required. Blue emitting superluminescent diodes with good performances and easy fabrication process are sought for next generation solid state lighting devices, micro-projectors and displays. These devices are laser diodes in which the optical feedback is inhibited, and lasing action avoided. Conventional fabrication processes minimize optical feedback by ad-hoc designs, e.g. anti-reflection coating, tilted waveguide or absorber sections, requiring specific fabrication steps. In this work, we propose and demonstrate the introduction of scattering defects in the device waveguide as a method for feedback inhibition. By performing pulsed laser ablation on a commercial 405 nm GaN laser diode we demonstrate a superluminescent diode, featuring a maximum output power of 2 mW and a spectral width of 5.7 nm.

physics.optics↗

arXiv2021

Electrically driven random lasing from a modified Fabry-Perot laser diode

Random lasers (RLs) are intriguing devices with promising applications as light sources for imaging, sensing, super resolution spectral analysis or complex networks engineering. RLs can be obtained from optically pumped dyes, optical fibers and crystals, or electrically pumped semiconductor heterostructures. Semicon-ductor RLs are usually fabricated by introducing scattering defects into the active layer, adding a degree of complexity to the fabrication process and losing the ease of realization potentially offered by disordered structures. Ready availability of electrically pumped RLs, avoiding costly fabrication approach, would boost the use of these devices in research and applications. Here, we realize an incoherent semiconductor RL by simply processing the output mirror of an off-the-shelf Fabry-Perot laser diode via controlled laser ablation. Optical feedback provided by the intact back mirror and the ablated front mirror results in multi-mode ran-dom lasing with low spatial coherence and speckled output emission profile.

physics.optics↗

arXiv2020

End-coupled random lasers: a basis for artificial neural networks

Light interference in strongly disordered photonic media can generate lasers where random modes are amplified in unpredictable way. The ease of fabrication, along with their low coherence caused by multiple small-linewidth peaks, made random lasers (RL) emerging, efficient, speckle-free light sources and a means to achieve spectral super-resolution. With potential to become a mature and accessible technology, their complex system's nature furnishes endless opportunities to unveil fundamental physics, since they can act as elements of optical network architectures. To date no experimental studies have analyzed the optical interaction between independent resonators in networks of RLs. Realizing RLs with a pumped strip joining two rough mirrors, we experimentally investigate and numerically simulate the emergence of networks when, by sharing scattering centers, RLs become coupled. We prove that the emission of a single RL can be manipulated by the action of others in the network, giving rise to substantial peak rearrangements and energy redistribution, fingerprint of mode coupling. Our findings, involving a few coupled RLs, firmly set the basis for the study of full-grown photonic networks. Oddly, both their deep understanding and their deployment as hardware clearly point in the direction of a novel disruptive technology: artificial intelligence on photonic random neural networks.

physics.optics↗