# Journal of Lightwave Technology

### Early Access Articles

Early Access articles are made available in advance of the final electronic or print versions. Early Access articles are peer reviewed but may not be fully edited. They are fully citable from the moment they appear in IEEE Xplore.

## Filter Results

Displaying Results 1 - 25 of 182
• ### All-Plasmonic IQ modulator with a 36μm Fiber-to-Fiber Pitch

Publication Year: 2019, Page(s): 1
| | PDF (804 KB)

A most compact all-metallic high-speed IQ modulator with a 36 μm fiber-to-fiber pitch operating at 200 Gbit/s is introduced. All components of the modulator are made of metal: The vertical crating couplers, the waveguides, polarization rotators, splitters and phase shifters. As the modulator relies on substrate-independent processes it can basically be put down on any smooth layer. The modulator i... View full abstract»

• ### Silicon multimode waveguide grating filter at 2 μm

Publication Year: 2019, Page(s): 1
| | PDF (1739 KB)

A silicon-based on-chip add-drop optical filter is realized for the wavelength-band of 2 μm by integrating a multimode waveguide grating (MWG) and a pair of two-channel mode (de)multiplexers. The realized add-drop optical filter has low loss and high sidelobe suppression ratio in a broad band, achieved by optimizing the corrugation depth, the apodization strength, as well as the grating length. Th... View full abstract»

• ### Noise Analysis of Zero-Forcing Nonlinear Equalizers for Coherent WDM Systems

Publication Year: 2019, Page(s): 1
| | PDF (380 KB)

We explore the fundamental limits on the achievable information rate of fiber-optic coherent transmission systems equipped with ideal zero-forcing nonlinear equalizer (ZFNLE). In the absence of amplifier noise, the ZFNLE forces the nonlinear signal-signal distortions to zero. If amplifier noise is included in the analysis, the equalization performance is severely limited by the nonlinear interacti... View full abstract»

• ### Efficient Light-to-Heat Conversion by Optical Absorption of a Metal on a Si Microring Resonator

Publication Year: 2019, Page(s): 1
| | PDF (1667 KB)

Optical absorption of a guided light wave in a waveguide by a metal is undesirable in many photonic integrated devices. However, the heating due to the optical absorption enables to realize novel applications such as non-volatile optical memories and all-optical thermo-optic devices. We report an efficient heating due to the optical absorption of an evanescent field by a metal heating layer deposi... View full abstract»

• ### A Neuromorphic Silicon Photonics Nonlinear Equalizer for Optical Communications with Intensity Modulation and Direct Detection

Publication Year: 2019, Page(s): 1
| | PDF (472 KB)

We present the design and numerical study of a nonlinear equalizer for optical communications based on silicon photonics and reservoir computing. The proposed equalizer leverages the optical information processing capabilities of integrated photonic reservoirs to combat distortions both in metro links of a few 100km and in high-speed short-reach Intensity-Modulation-Direct-Detection links. We show... View full abstract»

• ### 70 Gb/s Low-Power DC-coupled NRZ Differential Electro-Absorption Modulator Driver in 55 nm SiGe BiCMOS

Publication Year: 2019, Page(s): 1
| | PDF (2858 KB)

We present a 70 Gb/s capable optical transmitter consisting of a 50 μm long GeSi electro-absorption modulator (integrated in Silicon Photonics) and a fully differential driver designed in a 55 nm SiGe BiCMOS technology. By properly unbalancing the output stage, the driver can be DC-coupled to the modulator thus avoiding the use of on-chip or external bias-Ts. At a wavelength of 1560 nm, open eye d... View full abstract»

• ### Anti-external interference sensor based on cascaded photonic crystal nanobeam cavities for simultaneous detection of refractive index and temperature

Publication Year: 2019, Page(s): 1
| | PDF (2723 KB)

We present an anti-external interference sensor based on cascaded Silicon-on-Insulator (SOI) ellipse stack major axis modulated photonic crystal (PC) nanobeam cavities (EPCNCs). Two PC nanobeam cavities, one covered with SU-8 cladding (cav1) and the other exposed to air directly (cav2), are cascaded to detect refractive index (RI) and temperature simultaneously. Three dimensional finite-difference... View full abstract»

• ### Algorithms for Blind Separation and Estimation of Transmitter and Receiver IQ Imbalances

Publication Year: 2019, Page(s): 1
| | PDF (1567 KB)

We propose a blind transmitter (Tx) and receiver (Rx) in-phase/quadrature (IQ) amplitude and phase imbalances estimation scheme based on a combination of analytical modelling and clustering algorithms. The proposed scheme can isolate and separately estimate Tx and Rx phase and amplitude imbalances, applicable to high-order multi-modulus signals, and hence is a great physical-layer-monitoring tool ... View full abstract»

• ### Parallel-integrated fiber Bragg gratings inscribed by femtosecond laser point-by-point technology

Publication Year: 2019, Page(s): 1
| | PDF (1692 KB)

Conventional grating-inscription technology usually inscribes only one fiber Bragg grating (FBG) in the core of an optical fiber. A novel femtosecond laser point-by-point technology was demonstrated to parallel-inscribe multiple FBGs, i.e. so-called parallel-integrated FBGs (PI-FBGs), with either different or the same reflection wavelengths in the core of a standard single-mode fiber. Single- or m... View full abstract»

Publication Year: 2019, Page(s): 1
| | PDF (1548 KB)

In this paper, we experimentally compared the performance of bit-loading discrete multi-tone (DMT) and pre-equalized discrete-Fourier-transform spread (DFT-Spread) DMT in Intensity Modulation with Direct Detection (IM/DD) system for 2-km optical interconnect for the first time. Pre-equalization is considered as one promising method to compensate the high-frequency power fading in wideband communic... View full abstract»

• ### Generalized Modeling of Optomechanical Forces Applied to PT-Symmetric Optical Microscale Resonators

Publication Year: 2019, Page(s): 1
| | PDF (1020 KB)

We propose an innovative optomechanical device, exploiting the force enhancement due to PT-Symmetry in resonant coupled optical cavities. In order to perform the study, we develop a generalized modelling of the Response Theory of Optical Forces (RTOF), including the loss and the gain effects in optical systems. The enhancement of optical force appears to be limited only by non-linearity and resolu... View full abstract»

• ### Ultra-Compact Terabit Plasmonic Modulator Array

Publication Year: 2019, Page(s): 1
| | PDF (917 KB)

A new plasmonic transmitter solution offering 0.8 Tbit/s on an ultra-compact 90 μm × 5.5 μm footprint is introduced. It comprises a densely arranged 4-channel plasmonic phase modulator array that directly interconnects an optical fiber array. Each plasmonic modulator features high-index grating couplers - for direct and efficient conversion from a fiber mode to a plasmonic slot mode and vice versa... View full abstract»

• ### Wide-frequency-range phase-locked photonic-microwave oscillator operated in a fiber-coupled remote station

Publication Year: 2019, Page(s): 1
| | PDF (1330 KB)

In the latest radio interferometer, a system equipped with a large number of receivers from low frequency to high frequency [~THz] was realized. In addition, an ultra-wide bandwidth receiver and a super terahertz receiver are being developed as next generation receivers. In this situation, a new local oscillator capable of handling next generation receivers is necessary. Due to the very wide bandw... View full abstract»

• ### Fiber-Optic Current Sensor Based on Ohmic Heating of a Silicon Fabry-Perot Interferometer

Publication Year: 2019, Page(s): 1
| | PDF (1225 KB)

A fiber-optic Fabry-Perot interferometer (FPI) is proposed and demonstrated as an electric current sensor based on ohmic heating with temperature self-compensation. The sensing head is fabricated by attaching a silicon pillar on the fiber tip as the FPI and inserting it into a molten Tin (Sn) sphere as the conducting medium. Two copper electrodes are also inserted into the Sn sphere and serve as t... View full abstract»

• ### WDM transmission with in-line amplification at 1.3μm using a Bi-doped fibre amplifier

Publication Year: 2019, Page(s): 1
| | PDF (1557 KB)

Extension in the reach of 1.3μm optical communication systems has traditionally been restricted by the availability of suitable low-noise fibre amplifiers. Addressing this challenge, we present the first repeatered wavelength division multiplexing (WDM) experiments using a bismuth-doped fibre amplifier (BDFA) that exhibits 8.4THz (50nm) of gain bandwidth in the O-band. WDM signals arranged either ... View full abstract»

• ### Probabilistic Constellation Shaping for Optical Fiber Communications

Publication Year: 2019, Page(s): 1
| | PDF (1227 KB)

We review probabilistic constellation shaping (PCS), which has been a key enabler for several recent record-setting optical fiber communications experiments. PCS provides both fine-grained rate adaptability and energy efficiency (sensitivity) gains. We discuss the reasons for the fundamentally better performance of PCS over other constellation shaping techniques that also achieve rate adaptability... View full abstract»

• ### Light-sheet skew-ray enhanced pump-absorption for sensing

Publication Year: 2019, Page(s): 1
| | PDF (1305 KB)

We present a new sensing technique exploiting light-sheet excitation of skew rays in a multimode fiber, which can be applied to enhance the sensitivity of a range of sensing mechanisms such as pump absorption. The underlying principle is that a light sheet (i.e. thin plane of light) can selectively concentrate the optimum ray group, giving rise to enhanced interaction between light and matter (e.g... View full abstract»

• ### Increasing the Spectral Efficiency of DDO-CE-OFDM Systems by Multi-Objective Optimization

Publication Year: 2019, Page(s): 1
| | PDF (5240 KB)

A multi-objective optimization was implemented to increase the spectral efficiency of direct-detection optical orthogonal frequency division multiplexing (OFDM) systems with constant-envelope (CE) signals. Based on a Genetic algorithm, the optimization procedure evaluate the impact of fiber injection power in the reduction of the guardband between the optical carrier and the CE-OFDM signals, optim... View full abstract»

• ### Improved Multi-grating Filtering Demodulation Method Based on Cascading Neural Networks for Fiber Bragg Grating Sensor

Publication Year: 2019, Page(s): 1
| | PDF (3801 KB)

In recent decades, fiber Bragg grating (FBG) sensors have proven useful for structural health monitoring. An accurate and low-cost FBG demodulation method is needed to improve the performance of these sensors in structural-monitoring applications. This paper presents an improved method of matched multi-FBG-filtering demodulation that uses two cascading artificial neural networks (ANNs). The first ... View full abstract»

• ### High-speed, directly-modulated widely tunable 1310 nm coupled cavity laser via multimode interference

Publication Year: 2019, Page(s): 1
| | PDF (891 KB)

We discuss the design and demonstration of a widely tunable laser operating at 1310 nm with ∼ 38 nm tuning range, > 35 dB side-mode-suppression-ratio (SMSR), and output powers of ∼ 3 mW per tuning wavelength. Greater than 50 channels are demonstrated on a material platform that consists of $\rm In_{0.70}Al_{0.17}Ga_{0.13}$ As multiple quantum wells (MQW) and View full abstract»

• ### Short-range Non-bending Fully Distributed Water/Humidity Sensors

Publication Year: 2019, Page(s): 1
| | PDF (768 KB)

Existing sensing technologies lack the ability to spatially resolve multiple sources of water or humidity without relying on the deployment of numerous inline sensors. A fully distributed approach has the potential to unlock a diverse range of applications, such as humidity mapping and liquid-depth measurements. We have explored a new direction towards what is, to the best of our knowledge, the fi... View full abstract»

• ### IMDD Transmission at Net Data Rate of 333 Gbps Using Over-100-GHz-Bandwidth Analog Multiplexer and Mach-Zehnder Modulator

Publication Year: 2019, Page(s): 1
| | PDF (2513 KB)

We demonstrate intensity-modulated direct-detection (IMDD) optical transmission at a record-high data rate with single wavelength and single polarization. The high data rate is achieved with simple optics by using electronic and electro-optic devices with large operation bandwidths. We use a digital-preprocessed analog-multiplexed digital-to-analog converter with a >100-GHz analog multiplexer (... View full abstract»

• ### Designing Graphene-based Multi-Mode Acousto-Plasmonic Devices

Publication Year: 2019, Page(s): 1
| | PDF (999 KB)

We design multi-mode acousto-plasmonic devices based on the surface acoustic wave (SAW) assisted gratings, required for exciting and tuning plasmonic waves on the graphene surface. The SAW assisted gratings can be realized and controlled by applying an appropriate AC signal to the electrode pairs. Three types of SAW assisted gratings are proposed, including uniform and dual-segment gratings as wel... View full abstract»

• ### Laser induced dispersion with stimulated Raman scattering in gas-filled optical fiber

Publication Year: 2019, Page(s): 1
| | PDF (592 KB)

Laser induced dispersion provides an all-optical means for dynamically controlling light propagation. Previous works on dispersion control with a laser beam make use of Kerr non-linearity, electromagnetic induced transparency and stimulated Brillouin scattering in optical fibers. Here we report, for the first time to our knowledge, optically controllable dispersion with stimulated Raman scattering... View full abstract»

• ### Optical beam expander with parabolic photonic bandgap reflector for efficient excitation of optical leaky wave antenna

Publication Year: 2019, Page(s): 1
| | PDF (1743 KB)

This paper proposes and demonstrates an optical leaky wave antenna (OWLA) excited by a beam expander consisting of a slab waveguide and parabolic photonic bandgap (PBG) reflector. Conventional OLWAs are usually excited through an adiabatic taper waveguide, but its large size is a drawback. The PBG reflector is easy to fabricate with the OLWA using Si photonics technology and its size is 10 times s... View full abstract»

## Aims & Scope

The Journal of Lightwave Technology is comprised of original contributions, both regular papers and letters, covering work in all aspects of optical guided-wave science, technology, and engineering. Manuscripts are solicited which report original theoretical and/or experimental results which advance the technological base of guided-wave technology. Tutorial and review papers are by invitation only. Topics of interest include the following: fiber and cable technologies, active and passive guided-wave componentry (light sources, detectors, repeaters, switches, fiber sensors, etc.); integrated optics and optoelectronics; and systems, subsystems, new applications and unique field trials. System oriented manuscripts should be concerned with systems which perform a function not previously available, out-perform previously established systems, or represent enhancements in the state of the art in general.

Full Aims & Scope

## Meet Our Editors

Editor-in-Chief
Gabriella Bosco
Politecnico di Torino