Optical Communications Industry Research Articles

Thin-film lithium niobate-based electro-optic comb cloning for self-homodyne coherent communication.

As the optical communication industry advances, metropolitan area networks (MANs) and radio access networks (RANs) are extensively deployed on a large scale, demanding energy-efficient integrated light sources and simplified digital signal processing (DSP) technologies. The emergence of thin-film lithium niobate (TFLN) has given rise to high-performance, energy-efficient on-chip modulators, making on-chip optical frequency comb (OFC) more appealing. Owing to the phase uniformity and stability of this chip-scale device, it has been possible to eliminate the carrier frequency phase estimation (CPE) in DSP stacks using comb-clone-enabled self-homodyne detection. Here we report the first use, to our knowledge, of a TFLN on-chip electro-optic (EO) frequency comb to realize comb cloning and self-homodyne coherent detection. We transmit three optical pilot tones and eight data channels encoded with 20 Gbaud polarization-multiplexed 16-ary quadrature amplitude modulation (PM-16-QAM) over 10 km and 80 km standard single-mode fibers. The bit error ratios (BERs) of the eight channels reach below 10-3, a result made possible by our on-chip comb. The scalability and mass producibility of on-chip EO combs, combined with the simplified DSP, show potential in our proposed fifth-generation (5G) RAN and MAN transmission scheme.

0–360 Degrees angular measurements using spatial displacement

The angle measurement is one of the fundamental measurement techniques required for a large number of applications. Many mechanical and optical measurement methods accomplish this task, requiring contact with the object or interference using multiple laser beams. We introduce a measurement for a given arbitrary angle accomplished by the conversion of the angle measurement to a spatial displacement measurement. The resolution of the angular measurement is a microradian, and it is limited only by the resolving power of a pixel. This measurement is almost independent of the specific wavelength, degree of coherence, and measurement distance. Moreover, our method realizes a non-contact and nondestructive angular measurement within the range of 0°–360°. We anticipate it to have important applications in optical communication systems and industry.

Beyond CPO: A Motivation and Approach for Bringing Optics Onto the Silicon Interposer

Co-packaged optics (CPO) technology is well positioned to break through the bottlenecks that impede efficient bandwidth scaling in key near-term commercial integrated circuits. We begin by providing some historical context for this important sea change in the optical communications industry. Then, motivated by GPU-based accelerated computing requirements, we investigate the next pain points that are poised to constrain bandwidth and efficiency in future CPO-based systems. We identify 2.5D integrated optics (i.e., bringing optics onto the interposer) as a promising solution that can enable continued scaling for these systems due to the dense wiring available which facilitates more efficient slow-and-wide electrical interfaces. We explore the benefits, challenges, and requirements associated with such tight coupling of the processors and optical engines by considering high-level photonic link design, technology, and packaging. We demonstrate the viability of a control loop which can adequately regulate temperature within the aggressive thermal environment. Then, we introduce a custom simulation framework that allows quantified comparisons of detailed design decisions; the simulations validate the feasibility of the general approach while also providing key guidance to designers on best directions to pursue for efficient optimization.

Fast all-fiber ultraviolet photodetector based on an Ag-decorated ZnO micro-pillar.

There are urgent demands of ultraviolet (UV) photodetectors with high sensitivity and fast response due to the wide application of ultraviolet light in the fields of medical treatment, space exploration, optical communication and semiconductor industry. The response speed of traditional ZnO-based UV photodetectors is always limited by the carrier mobility and electrical resistance caused by the external circuits. Utilizing the all-optical detection method may replace the complex circuit structure and effectively improve the response speed of photodetectors. Here, a fast-response fiber-optic UV photodetector is proposed, where a ZnO micro-pillar is fixed on the end face of a fiber-tip and acts as a Fabry-Pérot interferometer (FPI). Under the irradiation of UV light, the photo-generated carriers change the refractive index of the ZnO micro-pillar, leading to a redshift of the interference wavelengths of the ZnO FPI. To enhance this effect, a discontinuous Ag film with an island-like structure is coated on the surface of ZnO micro-pillars through magnetron sputtering, and therefore the sensitivity of the proposed device achieves to 1.13 nm/(W·cm-2), which is 3.9 times higher than that of without Ag-decoration, due to the intensification of photo-carrier change with the help of the Schottky junction formed between Ag film and ZnO micro-pillar. Meanwhile, since the response speed of the proposed device is mainly determined by the temporal RI change of ZnO micro-pillar, the fiber-optic UV photodetector also shows very fast response with a rise time of 35 ns and a decay time of 40 µs. The demonstrated structure takes full advantage of optical fiber devices, exhibiting compactness, flexibility, fast response and immune to electromagnetic interference, which paves a new way for the next generation of photodetection devices.

Empirical Study on the Integration of Industry and Education in Suzhou Optoelectronic Industry

Based on the case analysis of the integration of industry and education in Suzhou optoelectronic industry, the implementation approach, operation mode and practical effect of the integration of industry and education are analyzed and studied. The results show that the Optoelectronic industry in Suzhou has combined with the professional (group) construction of vocational colleges and actively developed the new mode of multi-agent, multi-form and diversified vocational education through the establishment of industry-education integration service organization, improved the quality of skilled personnel training and the precision of service for the optical communication industry, and promoted the coordinated development of the industry and vocational education.

Small All-Range Lidar for Asteroid and Comet Core Missions

We report the development of a new type of space lidar specifically designed for missions to small planetary bodies for both topographic mapping and support of sample collection or landing. The instrument is designed to have a wide dynamic range with several operation modes for different mission phases. The laser transmitter consists of a fiber laser that is intensity modulated with a return-to-zero pseudo-noise (RZPN) code. The receiver detects the coded pulse-train by correlating the detected signal with the RZPN kernel. Unlike regular pseudo noise (PN) lidars, the RZPN kernel is set to zero outside laser firing windows, which removes most of the background noise over the receiver integration time. This technique enables the use of low peak-power but high pulse-rate lasers, such as fiber lasers, for long-distance ranging without aliasing. The laser power and the internal gain of the detector can both be adjusted to give a wide measurement dynamic range. The laser modulation code pattern can also be reconfigured in orbit to optimize measurements to different measurement environments. The receiver uses a multi-pixel linear mode photon-counting HgCdTe avalanche photodiode (APD) array with near quantum limited sensitivity at near to mid infrared wavelengths where many fiber lasers and diode lasers operate. The instrument is modular and versatile and can be built mostly with components developed by the optical communication industry.

T-shaped reflective polarizer under second Bragg incidence

A T-shaped reflective grating device under the second Bragg angle is proposed for polarizer. This grating device is mainly made of fused silica with T-shaped ridges, which can diffract the energy of the TE-polarized light and the TM-polarized light to the −2nd order and the 0th order with the reflective efficiency of each order more than 95%. Normalized field magnitude distribution and overlap integral are analyzed to explain the physical mechanism and energy exchange. Based on the optimized results, the beam splitter exhibits high efficiency, good extinction ratio and optical properties of the incident bandwidth. Moreover, grating can have longer period for easy fabrication under second Bragg incidence compared to reported Bragg incidence. Therefore, the T-shaped reflective grating device should be useful for the future optical communication industry.

Optical Fiber Communication Technology: Present Status and Prospect

As an important application of laser technology, optical fiber communications are key enablers for the current information age. With the emergence of new technologies including Internet of Things, big data, cloud computing, virtual reality, and artificial intelligence, there are growing needs in the society for high capacity information transmission, which puts forward higher requirements for the optical fiber communication technology. Based on a systematic review of the development status of the technology in China and abroad, this paper analyzes the problems and challenges it faces in the application of specific scenarios, and prospects the development of some related technologies in the future. Through analysis, the challenges in optical fiber communication systems with an ultra-large capacity can be solved by increasing the transmitted power, raising the bandwidth of optical amplifiers, and conducting research on low-loss optical fibers and technologies related to space division multiplexing. The cost problems of the systems in other scenarios are also considered. In general, the optical fiber communication technology is evolving toward the direction of ultra-large capacity, intelligence, and integration. It is hoped to realize intelligent monitoring of network parameters, as well as ultra-long distance and ultra-large capacity transmission. With the development of devices and integration technology, the optical fiber communication industry continues to move forward toward the goal of high performance and low cost.

Technical Research on High Performance Fully Compatible FMC Fast Connector

With the rapid development of the optical communication industry, the implementation of national policies, the increase of broadband access fiber-to-the-home investment, and the continuously increased requirements for the important components in the construction and deployment of FTTH system solutions of the communication industry, fiber connection has become an important link in FTTH. The fast connector has become the main method of optical connection, and the emergence of the fast connector solves the problem that the optical fiber can only be spliced. This article mainly introduces the basic characteristics and technical parameters of high-performance fully compatible FMC fast connectors which is an important device in the construction and deployment of the current FTTH system solution. By implementing the basic characteristic of “high performance” and “fully compatible”, it can meet all the terminal connection demand under various FTTH constructions deployment. And at the same time, this article briefly explains the convenience of construction and practical application of the FMC fast connectors. Through the optimization and improvement of various performances, the connector product has become an important technology for future FTTH network construction. It is suitable for terminal connection in various FTTH construction deployment environments, reducing on-site construction costs, improving assembly efficiency, providing convenience and services, and meeting the needs of customer terminal connection with different usage habits.

Hesitant-Fuzzy Sets-Based Computational Approach for Evaluating the Survivability Impact of Multi-Fiber WDM Networks: Kingdom of Saudi Arabia Perspective

Saudi Arabia's Information and Communication Technology (ICT) industry is undergoing different stages of modernization. Over the last few decades, the ICT industry has been experiencing rapid growth. The understanding of disruption as well as fluctuation in channel capacity gives an idea about the optical fiber network. A primary necessity for the optical communication industry is to achieve the desired effect of survival and growth. Scientific researchers are trying to achieve the objective of optimum optical network services survivability. The proposed paper attempts to describe and analyze the effect of multiplexing in multi-fiber wavelength. To analyze and assess the effect in more scientific and systematic manner, the authors have used a multi criteria decision making (MCDM) approach named the hesitant fuzzy analytical hierarchy process as well as TOPSIS methods in this paper. With the help of these adopted MCDM approaches, the authors have assessed the surviving strength and capacity of multiplexing. For this empirical model, five features and two levels of alternatives were chosen. A combination of two principal alternatives was the first level, and the second level had its five based alternatives. For this analysis, the unified symmetrical decision making strategy of Hesitant-Fuzzy AHP with Hesitant-Fuzzy TOPSIS was established. The findings obtained on survivability in this research will be a point of reference for developing the next level wavelength division multiplexing in optical transmission network communication. In the sense of producing gigabits and terabits per second, this inquiry will further reinforce optical fiber connectivity.

Recovery of germanium from waste Optical Fibers by hydrometallurgical method

With the rapid development of optical fiber communications industry, germanium as main raw materials of optical fiber cables become more important in recent years. Due to the scarcity and importance of germanium, we developing an effective recycling process of recovering germanium metal from waste fiber optic cables. The process was arranged to do pre-treatment, leach the fiber and extract the germanium from silicon. In the leaching step, the concentration of different acid, reaction time and liquid-solid ratio were investigated. At the solvent extraction process, the pH value, concentration of extractant and stripping agents, organic-aqueous ratio and reaction time were considered. In leaching step, germanium and silicon were dissolved in solution by sulfuric acid and hydrofluoric acid. Then, germanium was extracted by Trioctylamine (TOA) to the organic phase and silicon was remained in the aqueous by controlling the conditions. After then, Germanium was then stripped by sodium hydroxide. With the optimal conditions, the recovery of germanium could be up to 99%. After separation, germanium could be recycled to back to the industrial effectively.

Predicting Global Minimum in Complex Beryllium Borate System for Deep-ultraviolet Functional Optical Applications.

Searching for high performance materials for optical communication and laser industry in deep-ultraviolet (DUV) region has been the subject of considerable interest. Such materials by design from scratching on multi-component complex crystal systems are challenging. Here, we predict, through density function calculations and unbiased structure searching techniques, the formation of quaternary NaBeBO3 compounds at ambient pressure. Among the four low-energy phases, the P63/m structure exhibits a DUV cutoff edge of 20 nm shorter than α-BaB2O4 (189 nm) – the best-known DUV birefringent material. While the P-6 structure exhibits one time second-harmonic generation efficiency of KH2PO4 and possesses excellent crystal growth habit without showing any layer habit as observed in the only available DUV nonlinear optical material KBe2BO3F2, whose layer habit limits its wide industrial applications. These NaBeBO3 structures are promising candidates for the next generation of DUV optical materials, and the structure prediction technique will shed light on future optical materials design.

Quantitative evaluation of fiber fuse initiation with exposure to arc discharge provided by a fusion splicer.

The optical communication industry and power-over-fiber applications face a dilemma as a result of the expanding demand of light power delivery and the potential risks of high-power light manipulation including the fiber fuse phenomenon, a continuous destruction of the fiber core pumped by the propagating light and triggered by a heat-induced strong absorption of silica glass. However, we have limited knowledge on its initiation process in the viewpoint of energy flow in the reactive area. Therefore, the conditions required for a fiber fuse initiation in standard single-mode fibers were determined quantitatively, namely the power of a 1480 nm fiber laser and the arc discharge intensity provided by a fusion splicer for one second as an outer heat source. Systematic investigation on the energy flow balance between these energy sources revealed that the initiation process consists of two steps; the generation of a precursor at the heated spot and the transition to a stable fiber fuse. The latter step needs a certain degree of heat accumulation at the core where waveguide deformation is ongoing competitively. This method is useful for comparing the tolerance to fiber fuse initiation among various fibers with a fixed energy amount that was not noticed before.

Novel applications of space-division multiplexing

Space-division multiplexing (SDM) using multi-core fibers (MCFs) and few-mode fibers (FMFs) was proposed as a solution to increase capacity and/or reduce the cost per bit of fiber-optic transmission. Advances in passive and active SDM devices as well as digital signal processing have led to impressive SDM transmission demonstrations in the laboratory. Although the perceived advantages in terms of capacity and cost per bit that SDM offers over parallel SMF bundles are not universally accepted, SDM is beginning to emerge as an indispensable solution in major network segments. The introduction of the spatial degree of freedom allows optical networks to overcome fundamental limitations such as fiber nonlinearity as well practical limitations such as power delivery. We describe these application scenarios that the optical communications industry has already began to explore. From a fundamental science point of view, concepts such as the principal modes, generalized Stokes space, and multi-component solitons discovered in SDM research will likely have a broad impact in other areas of science and engineering.

Optimal Design of High-Speed Optical Fiber Communication System Spectral Efficiency of New Modulation Formats

As human society to the information in the process of moving and growing demand for bandwidth communications capacity, the optical of new modulation formats increasingly attention and quickly play an important role in optical communications. How can the system bit error rate within a certain degree of stability while still maintaining high-speed long-distance dispersal system, has been a popular issue is the optical communications industry. Starting from the optical modulation format herein, the generation process of the system introduced various optical signal modulation format, the optical signal through the optical fiber was studied and the performance of the simulation, on the basis of the design of advanced optical modulation formats in an optical fiber communication system .

Passive optical network architectures [Series Editorial

Global optical communications industry showed progress in all segments from access to core networks in 2013. Although fiber-based broadband access network deployments were slower than expected with service provider attention focused on recent developments and new technologies for copper- based broadband access, we witnessed steady developments in next generation optical access (NGOA) standards and field trials.

Advances in optical networking [Series Editorial

The global optical communications industry continues to show progress in all segments from access to core networks. Fiber-based broadband access network deployments have been slow and steady with service provider attention currently focused on recent developments and new technologies for higher bandwidth copper-based broadband access. Service providers have continued their deployments, globally, of high-speed (100G and beyond) transport networks, and have been participating in field trials of 400G optical transport network equipment and systems. Since the beginning of 2013, there have been more focus and attention on network functions virtualization (NFV) and software-defined networking (SDN) to provide service providers with the tools for more effective operation and management of optical communications networks.

Diode lasers: From laboratory to industry

The invention of first laser in 1960 triggered the discovery of several new families of lasers. A rich interplay of different lasing materials resulted in a far better understanding of the phenomena particularly linked with atomic and molecular spectroscopy. Diode lasers have gone through tremendous developments on the forefront of applied physics that have shown novel ways to the researchers. Some interesting attributes of the diode lasers like cost effectiveness, miniature size, high reliability and relative simplicity of use make them good candidates for utilization in various practical applications. Diode lasers are being used by a variety of professionals and in several spectroscopic techniques covering many areas of pure and applied sciences. Diode lasers have revolutionized many fields like optical communication industry, medical science, trace gas monitoring, studies related to biology, analytical chemistry including elemental analysis, war fare studies etc. In this paper the diode laser based technologies and measurement techniques ranging from laboratory research to automated field and industry have been reviewed. The application specific developments of diode lasers and various methods of their utilization particularly during the last decade are discussed comprehensively. A detailed snapshot of the current state of the art diode laser applications is given along with a detailed discussion on the upcoming challenges.

Advances in optical communications [Series Editorial

The global optical communications industry has continued to show progress through the first half of 2013. Although optical access network deployments have been slower, we have been witnessing steady progress in fiber-based broadband access network growth. Communications service providers have continued their deployment of high-speed (100G and beyond) transport networks, and have been participating in field trials of higher-speed optical transport network equipment and systems.

Optical network architectures [Series Editorial

In the first quarter of this year, the optical communications industry's major event, OFCNFOEC '13, was held in Anaheim, California, with global participation (in excess of 12,000 attendees) in the conference's technical program and exhibit (more than 550 exhibiting companies). More than 800 technical presentations covered a broad range of optical communications technologies from advances in high-speed optical transport, software-defined networking (SDN), silicon photonics to optical interconnects in future computing systems, as well as progress in optical test and measurement. As we have witnessed in the past years, a vibrant global optical communications industry was in display at this year's OFCNFOEC.