Wireless sensor networks (WSNs) are used in many applications to gather sensitive information which is then forwarded an analysis center. Resource limitations have be taken into account when designing a WSN infrastructure. Unbalanced energy consumption inherent problem WSNs, characterized by multihop routing and many-to-one traffic pattern. This uneven dissipation can significantly reduce network lifetime. paper proposes new method for WSNs extend lifetime using combination of fuzzy approach...

An all-fiber approach to generate triangular-shaped pulses based on frequency-to-time conversion is proposed and demonstrated. Two filter modules that have sinusoidal spectral responses are cascaded create a optical spectrum. Through the in dispersive fiber, periodic triangular with same shape as spectrum obtained. The repetition rate pulse width of generated signals can be tuned by adjusting modulation dispersion value, respectively.

Increasing the system capacity and spectral efficiency (SE) per unit bandwidth is one of ultimate goals for data network designers, especially when using technologies compatible with current embedded fiber infrastructures. Among these, polarization-division-multiplexing (PDM) scheme, which supports two independent channels on a single wavelength orthogonal polarization states, has become standard in most state-of-art telecommunication systems. Currently, however, only states (that is, PDM)...

Nowadays, the microwave photonics (MWP) concept has been evolved from laboratory tests to practical applications, and related techniques have widely deployed in many fields including such as wireless communications, medicine, sensing, radars, electronic warfare, space explorations. In this paper, we concentrate on featured applications of MWP high-speed railways (HSRs), an emerging field massive market, overview about our recent work is presented. The radio-over-fiber based communications...

An adaptive image restoration algorithm based on 2-D bilateral filtering has been proposed to enhance the signal-to-noise ratio (SNR) of intrusion location for phase-sensitive optical time domain reflectometry (Φ-OTDR) system. By converting spatial and information Φ-OTDR traces into image, can smooth noise preserve useful signal efficiently. To simplify algorithm, a Lorentz function is adopted replace original Gaussian function, which higher practicability. Furthermore, an parameter setting...

Chaotic optical communication technology is considered as an effective secure technology, which can protect information from a physical layer and compatible with the existing networks. At present, to realize long-distance chaos synchronization still very difficult problem, mainly because well-matched hardware cannot always be guaranteed between transmitter receiver. In this Letter, we introduce long short-term memory (LSTM) networks learn nonlinear dynamics model of opto-electronic feedback...

A photonic approach to the instantaneous measurement of multiple frequency components using a spectrally sliced incoherent source (SSIS) is proposed. In proposed system, broadband an etalon generate SSIS. Each channel SSIS externally modulated by microwave signal containing components. The then sent second etalon. Thanks difference between free spectral ranges two etalons, are simultaneously estimated from power distribution at output channels Compared with use laser array, provides simpler...

The unpredictability degree and bandwidth properties of chaotic signals generated by semiconductor lasers subject to dual optical injections (DCOI) are investigated numerically. is evaluated quantitatively via permutation entropy. Compared with the slave laser (SL) single injection, both can be enhanced significantly for SL DCOI. effects injection strength, frequency detuning as well feedback strength considered. It shown that, increase increases firstly then decreases until saturates at a...

A plasmonic bus waveguide with a side-coupled T-shaped (TS) or reverse (RTS) resonator consisting of parallel and perpendicular cavities is proposed. The compact configuration could serve as wavelength demultiplexing device forbidden band achieved based on the symmetric distribution resonators. By shifting one cavity away from center resonator, system exhibits electromagnetically induced transparency (EIT) like transmission at former band. electromagnetic responses structure be handled...

Dynamic cholesteric liquid crystal superstructures with rationally designed arrangements of in-plane helical axes are enabled by utilizing a digital micromirror device-based photoalignment technique, resulting in unique fingerprint textures for potential advanced photonic applications. General rules behind the axis manipulation investigated and growth spiral wave-like continuous gratings demonstrated.

We experimentally demonstrate a modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring method for digital coherent receivers by using the specific features of received signals' density distributions in Stokes axes combined with deep neural networks (DNNs). The distribution fitting curves S1 S2 depend on signal's OSNR. proposed technique extracts these curves' first-order derivation MFI OSNR monitoring, order to improve probability correct estimation...

Phase-sensitive optical time domain reflectometry (Φ-OTDR) realizes quantitative measurement of the dynamic strain employing phase demodulation. Unfortunately, it is difficult to measure large with conventional Φ-OTDR due restriction unwrapping algorithm. In this work, an approach based on two-wavelength probe proposed and demonstrated improve measurable range in Φ-OTDR. By utilizing difference between two phases acquiring different lasers, can be recovered. experiments, strains peak values...

An approach of phase-shift transform is proposed and demonstrated to suppress the interference fading in phase sensitive optical time domain reflectometry (Φ-OTDR). The executed digital complicated frequency modulation not required. operation principle carefully analyzed a signal with complementary amplitude can be obtained this method. Through synthesizing signals, false phases corrected. Benefiting from flexibility approach, multiple transforms are implemented make sure that all retrieved...

We propose and experimentally demonstrate a photonic approach to the measurement of time-difference-of-arrival (TDOA) angle-of-arrival (AOA) microwave signal. In proposed system, TDOA AOA are equivalently converted into phase shift between two replicas signal received at cascaded modulators. The light wave from CW laser is externally modulated by first modulator, which biased suppress optical carrier, leading generation first-order sidebands, further phase-delayed second modulator. Two...

We investigate a plasmonic waveguide system based on side-coupled complementary split-ring resonators (CSRR), which exhibits electromagnetically induced transparency (EIT)-like transmission. LC resonance model is utilized to explain the electromagnetic responses of CSRR, verified by simulation results finite difference time domain method. The CSRR can be flexible handled changing asymmetry degree structure and width metallic baffles. Cascaded CSRRs also have been studied obtain EIT-like...

We numerically investigate the chaos synchronization and message transmission between two mutual coupling semiconductor lasers (MCSLs) subject to identical unidirectional injections (UIs) from an external cavity laser (ECSL). The MCSLs is realized through injection locking in conjunction with symmetric operation. simulation results show that stable isochronal can be achieved under proper driving injections. This type of robust parameter mismatch up tens percentage frequency detuning several...

Numerical and experimental investigations of time delay concealment chaos bandwidth enhancement in three semiconductor lasers with a cascade scheme are presented. The system is composed an external-cavity master laser, solitary intermediate slave laser. results show that the first two used for concealing signature, last enhancement. For large parameter regions injection strength frequency detuning, chaotic signals simultaneously achieved by adopting simple configuration.

A method to improve the linearity of analog photonic link is proposed and experimentally demonstrated, which consists a phase modulator an optical tunable bandpass filter. By carefully optimizing bandwidth center wavelength filter, we can significantly suppress third-order intermodulation distortion by ~32 dB. Subsequently spurious-free dynamic range improved ~14

A novel measurement scheme for multiple high-frequency vibrations has been demonstrated by combining phase-sensitive optical time domain reflectometry (Ф-OTDR) and Mach-Zehnder interferometer (MZI) based on frequency division multiplexing. The light source is directly launched into the MZI structure, while it was modulated an acoustic modulator (AOM) with a shift of 200 MHz Ф-OTDR part. vibration obtained demodulating interference signal position located system. spatial resolution 10m over 3...

Optical modulation format identification is critical in the next generation of heterogeneous and reconfigurable optical networks. Here, we present a blind method by applying fast density-peak-based pattern recognition autonomous receiver elastic In this paper, find that different types show energy level features which can be used as metric to identify these formats two-dimensional Stokes plane. The proposed does not require training symbols, insensitive carrier phase noise, frequency offset...

Photonic generation of wideband chaotic signals with time delay signature elimination is investigated experimentally and numerically based on a semiconductor laser (slave laser) optical injection from master laser. The subject to moderate feedback where the strength external-cavity length are fixed, while slave stands alone. experimental results show that successful concealment can be generated in by simply adjusting coupling frequency detuning between two lasers. Furthermore, numerical...

A photonic scheme to generate a phase-coded microwave signal with tunable carrier frequency based on simple single-trip and two-pass structure is proposed. Facilitated by the fiber Bragg grating phase modulator along trip, both doubling coding could be achieved simultaneously. Phase-coded signals at 20 22 GHz are experimentally generated.