Physical unclonable functions are the physical equivalent of one-way mathematical transformations that, upon external excitation, can generate irreversible responses. Exceeding their counterparts, inherent complexity renders them resilient to cloning and reverse engineering. When these features combined with time-invariant deterministic operation, necessity store responses (keys) in non-volatile means be alleviated. This pivotal feature, makes critical components for a wide range...

Abstract The use of fiber infrastructures for environmental sensing is attracting global interest, as optical fibers emerge low cost and easily accessible platforms exhibiting a large terrestrial deployment. Moreover, networks offer the unique advantage providing observations submarine areas, where sparse existence permanent seismic instrumentation due to difficulties in deployment limits availability high-resolution subsea information on natural hazards both time space. techniques that...

SUMMARY We present a theory and conceptual examples for fibre-optic deformation sensing based on phase changes of transmitted light. As first result, we establish an exact relation between observable the tensor along fibre. This is nonlinear includes effects related to both local in fibre length deformation-induced refractive index. In cases where norm much smaller than 1, useful first-order can be derived. It connects integral over in-line strain times When spatial variations index are...

Distributed Acoustic Sensing (DAS) has become a popular method of observing seismic wavefields: backscattered pulses light reveal strains or strain-rates at any location along fiber-optic cable. In contrast, few newer systems transmit through cable and collect integrated phase delays over the entire cable, such as Microwave Frequency Fiber Interferometer (MFFI). These can be deployed significantly longer distances, may used in conjunction with live telecommunications, cheaper. However, they...

Physical Layer Security (PLS) exploits characteristics and properties of the physical layer for data encryption supplements conventional cryptography enhanced overall security. Most PLS methodologies rely on (statistical) transmission channel to either generate secure keys, or exploit them together with other (i.e. advanced modulation schemes) transmission. However, these approaches often lead increased complexity therefore become impractical actual system implementation. Recent advancements...

In this letter, the discrete Fourier transform-spread multitone modulation (DFT-spread DMT) scheme has been used for first time in laser-based short range optical transmission (over 100 m) with 1-mm step-index plastic fiber link, and its superior performance, compared standard DMT scheme, was demonstrated. The DFT-spread combines advantages of both single carrier multicarrier together a lower peak-to-average power ratio. Under same experimental conditions, bit-error-rate is achieved rates...

SUMMARY Fibre-optic sensing based on transmission offer an alternative to scattering-based distributed acoustic (DAS). The ability interrogate fibres that are thousands of kilometres long opens opportunities for studies remote regions, including ocean basins. However, by averaging deformation along the fibre, systems produce integrated instead measurements. They defy traditional interpretations in terms simple seismic phases, thereby inherently requiring a full-waveform approach. For this,...

We experimentally demonstrate a microwave frequency dissemination system operating as sensitive interferometric sensor of seismic waves on commercially deployed fiber networks in Attika, Greece. Efficient detection from distant epicenters (>400km) is presented

Abstract The use of fiber infrastructures for environmental sensing is attracting global interest, as optical fibers emerge low cost and easily accessible platforms exhibiting a large terrestrial deployment. Moreover, networks offer the unique advantage providing observations submarine areas, where sparse existence permanent seismic instrumentation due to difficulties in deployment limits availability high-resolution subsea information on natural hazards both time space. techniques that...

This manuscript is concerned with phase changes of signals transmitted through deforming optical fibres. As a first result, it establishes an exact relation between observable and the deformation tensor along fibre. non-linear, includes effects related to both local in fibre length deformation-induced speed light or refractive index. In seismic applications, where norm earthquake-induced orders magnitude smaller than 1, useful first-order can be derived. It simply connects integral over...

Currently there are multiple approaches considered by the optical communications community in order to scale-up transceiver bit-rates beyond Tb/s mark. Those include implementations based on higher baud-rates, advanced modulation formats and some form of parallelism, either using Parallel Fibers Multiplexing (PSM) or Wavelength Division (WDM), both. However, cost power consumption resulting transceivers, normalized per Gb/s, do not drop linearly as number parallel lanes (utilizing spatial...

We propose and experimentally validate a new cost-effective optical receiver-regenerator scheme for long-distance microwave-frequency standard dissemination, based on the properties of dual-wavelength injection locked Fabry-Perot (FP) lasers. The regenerator FP laser is to one its longitudinal modes by incoming intensity-modulated light carrying standard. local CW also injected in FP, locking it an adjacent mode. dual-injection reproduces sinusoidal both wavelengths. regenerated original...

The fundamental properties of free space optical channels in the ultraviolet (UV) spectral range between 200 and 280 nm are enhanced scattering solar blind operation. Exploiting these properties, point-to-point links a non-line-of-sight (NLOS) regime were experimentally tested performance pulse position modulation fourth order (4-PPM) flip-orthogonal frequency division multiplexing (Flip-OFDM) formats was evaluated. At transmitting side, light-emitting diodes (LEDs) emitting at 265 used....

In this Letter, we conceptually demonstrate the potential of a phase-sensitive amplifier to operate as an active detector stochastic phase changes in fiber-based frequency dissemination systems with two orders magnitude better sensitivity than state-of-the-art one-way relying on two-wavelength schemes. Theoretical and experimental analyses show that these (caused by environmental changes, e.g., due temperature) can be detected high via optical comparison performed within amplifier....

Multicore fibers can be used for Radio over Fiber transmission of mmwave signals phased array antennas in 5G networks. The inter-core skew these distort the radiation pattern. We propose an efficient method to compensate differential delays, without full equalization path lengths, reducing power loss and complexity.

A monolithic passively mode-locked laser is proposed as a compact optical sensor for displacements and vibrations of reflecting object. The sensing principle relies on the change repetition frequency that induced by feedback from object under measurement. It has been previously observed that, when semiconductor mode locked receives sufficient level an external surface it exhibits no more determined mode-locking rule free-running operation but imposed length cavity. Therefore measurement...

Over the recent years many modulation schemes were proposed for laser based high-speed short-range transmission over step-index plastic optical fiber (SI-POF). Among these schemes, CAP and DFT-Spread DMT demonstrated a good performance intensity direct-detection via SI-POF. In this work, first time, we report on progress initial experimentation regarding comparison of 50m 1-mm It is shown that achieve comparable rate given bit error same experimental configuration.

In this letter, rate-adaptive bit-loading techniques are explored for maximizing the transmission rate of spreading multicarrier modulation schemes over step index plastic optical fiber (SI-POF) short range links. Both discrete Fourier transform (DFT)-spread multitone (DMT) and code division multiple access-DMT experimentally evaluated compared against conventional adaptive DMT, a 50-m intensity direct-detection (IM/DD) link 1-mm PMMA SI-POF. It is shown that both achieve better performance...

Perovskite is an emerging low-cost and high-quality material, that show significant potential to revolutionize photovoltaic lighting sectors in Organic Large Area Electronics (OLAE) devices. Their simple inexpensive processing methods, such as solution-based synthesis printing, make them attractive for flexible lightweight electronic In this work, perovskite suitability has been tested telecommunication applications, particularly Li-Fi links. The devices were integrated into a telecom...

The integration of QKD systems in Metro optical networks raises challenges which cannot be completely resolved with the current technological status. In this work we devise a methodology for identifying different kind impairments may occur on quantum channel during its transmission an operational network. is built around supervised ML pipeline using as input QBER and SKR time-series requires no further interventions system. identification happens real time even though such information...

The integration of QKD systems in metro optical networks raises challenges that cannot be fully resolved with current technological means. In this work, we devised a methodology for identifying different types impairments link embedded communication network. Identification occurs real time using supervised machine learning model designed purpose. takes only QBER and SKR time-series data as the input, making its applicability not restricted to any specific protocol or system. output specifies...