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Showing papers on "Wavelength-division multiplexing published in 2011"


Journal ArticleDOI
TL;DR: In this article, the performance of Nyquist-WDM Terabit superchannels implemented using polarization-multiplexed phase shift-keying based on 2 (PM-BPSK) and 4 (PM)-QPSK signal points was investigated through simulations.
Abstract: We investigated through simulations the performance of Nyquist-WDM Terabit superchannels implemented using polarization-multiplexed phase shift-keying based on 2 (PM-BPSK) and 4 (PM-QPSK) signal points or polarization-multiplexed quadrature amplitude modulation based on 8 (PM-8QAM) and 16 (PM-16QAM) signal points. Terabit superchannels are obtained through the aggregation of multiple subcarriers using the Nyquist-WDM technique, based on a tight spectral shaping of each subcarrier which allows very narrow spacing. We first studied the optimum transmitter/receiver filtering in a back-to-back configuration. Then we investigated the maximum reach for different spectral efficiencies, after nonlinear propagation over uncompensated links with lumped amplification. Performance for systems based on both standard single-mode fiber (SSMF) and large effective area non-zero dispersion-shifted fiber (NZDSF) has been analyzed. Assuming SSMF with 25-dB span loss, we found that PM-BPSK can reach 6480 km at a net capacity of 4 Tb/s across the C band. Conversely, PM-16QAM can deliver 27 Tb/s, but over 270 km only. Note that a lower span length, the use of Raman amplification and/or pure silica-core fibers (PSCFs) can significantly increase the maximum reach, but without changing the hierarchy among the performance of modulation formats. We also show that the maximum reachable distance is approximately 2/3 of the one achievable in linear propagation at the optimum launch power, regardless of the modulation format, spacing and fiber type. As additional results, we also verified that the optimum launch power per subcarrier linearly depends on the span loss, varies with the fiber type, but it is independent of the modulation format, and that the relationship between the maximum reachable distance and the span loss is almost linear.

545 citations


Journal ArticleDOI
TL;DR: It is shown that 6×6 MIMO processing can be used to almost completely compensate for crosstalk and intersymbol interference due to mode coupling in a system that transmits uncorrelated 28-GBaud QPSK signals on the six spatial and polarization modes supported by a novel few-mode fiber.
Abstract: Mode-division multiplexing over 33-km few-mode fiber is investigated. It is shown that 6×6 MIMO processing can be used to almost completely compensate for crosstalk and intersymbol interference due to mode coupling in a system that transmits uncorrelated 28-GBaud QPSK signals on the six spatial and polarization modes supported by a novel few-mode fiber.

489 citations


Journal ArticleDOI
TL;DR: This paper discusses MIMO capacities in optical SDM systems, including related outage considerations which are an important part in the design of such systems, and extracts scaling rules for mode-average and mode-dependent loss.
Abstract: With wavelength-division multiplexing (WDM) rapidly nearing its scalability limits, space-division multiplexing (SDM) seems the only option to further scale the capacity of optical transport networks. In order for SDM systems to continue the WDM trend of reducing energy and cost per bit with system capacity, integration will be key to SDM. Since integration is likely to introduce non-negligible crosstalk between multiple parallel transmission paths, multiple-input multiple output (MIMO) signal processing techniques will have to be used. In this paper, we discuss MIMO capacities in optical SDM systems, including related outage considerations which are an important part in the design of such systems. In order to achieve the low-outage standards required for optical transport networks, SDM transponders should be capable of individually addressing, and preferably MIMO processing all modes supported by the optical SDM waveguide. We then discuss the effect of distributed optical noise in MIMO SDM systems and focus on the impact of mode-dependent loss (MDL) on system capacity and system outage. Through extensive numerical simulations, we extract scaling rules for mode-average and mode-dependent loss and show that MIMO SDM systems composed of up to 128 segments and supporting up to 128 modes can tolerate up to 1 dB of per-segment MDL at 90% of the system's full capacity at an outage probability of 10(-4).

401 citations


Journal ArticleDOI
TL;DR: In this contribution the important developments in the field of Er-doped integrated waveguide amplifiers and lasers are reviewed and current and future potential applications are explored.
Abstract: Erbium-doped fiber devices have been extraordinarily successful due to their broad optical gain around 1.5–1.6 μm. Er-doped fiber amplifiers enable efficient, stable amplification of high-speed, wavelength-division-multiplexed signals, thus continue to dominate as part of the backbone of longhaul telecommunications networks. At the same time, Er-doped fiber lasers see many applications in telecommunications as well as in biomedical and sensing environments. Over the last 20 years significant efforts have been made to bring these advantages to the chip level. Device integration decreases the overall size and cost and potentially allows for the combination of many functions on a single tiny chip. Besides technological issues connected to the shorter device lengths and correspondingly higher Er concentrations required for high gain, the choice of appropriate host material as well as many design issues come into play in such devices. In this contribution the important developments in the field of Er-doped integrated waveguide amplifiers and lasers are reviewed and current and future potential applications are explored. The vision of integrating such Er-doped gain devices with other, passive materials platforms, such as silicon photonics, is discussed.

301 citations


Journal ArticleDOI
TL;DR: This paper presents a probabilistic analysis of the survivability of NG-PONs and hybrid fiber-wireless (FiWi) access networks, taking both optical and wireless protection into account, and proposes different selection schemes to wirelessly upgrade a subset of ONUs.
Abstract: Passive optical networks (PONs) are currently evolving into next-generation PONs (NG-PONs) which aim at achieving higher data rates, wavelength channel counts, number of optical network units (ONUs), and extended coverage compared to their conventional counterparts. Due to the increased number of stages and ONUs, NG-PONs face significant challenges to provide the same level of survivability like conventional PONs without exceeding the budget constraints of cost-sensitive access networks. Toward this end, partial optical protection, in combination with interconnecting a subset of ONUs through a wireless mesh network (WMN) front-end, are promising solutions to render NG-PONs survivable in a cost-effective manner. In this paper, we present a probabilistic analysis of the survivability of NG-PONs and hybrid fiber-wireless (FiWi) access networks, taking both optical and wireless protection into account. In addition, we propose different selection schemes to wirelessly upgrade a subset of ONUs, and investigate their performance for a wide range of fiber link failure scenarios and different NG-PON topologies.

257 citations


Journal ArticleDOI
TL;DR: A new multicore fiber having seven single-mode cores arranged in a hexagonal array, exhibiting low crosstalk among the cores and low loss across the C and L bands is described.
Abstract: We describe a new multicore fiber (MCF) having seven single-mode cores arranged in a hexagonal array, exhibiting low crosstalk among the cores and low loss across the C and L bands. We experimentally demonstrate a record transmission capacity of 112 Tb/s over a 76.8-km MCF using space-division multiplexing and dense wavelength-division multiplexing (DWDM). Each core carries 160 107-Gb/s polarization-division multiplexed quadrature phase-shift keying (PDM-QPSK) channels on a 50-GHz grid in the C and L bands, resulting in an aggregate spectral efficiency of 14 b/s/Hz. We further investigate the impact of the inter-core crosstalk on a 107-Gb/s PDM-QPSK signal after transmitting through the center core of the MCF when all the 6 outer cores carry same-wavelength 107-Gb/s signals with equal powers, and discuss the system implications of core-to-core crosstalk on ultra-long-haul transmission.

252 citations


Journal ArticleDOI
TL;DR: A novel optical transmission system based on a programmable liquid crystal on silicon panel, a prototype few-mode fiber, and a 4×4 multiple input multiple output algorithm processing the information of two polarization diversity coherent receivers to experimentally demonstrate the possibility of mode division multiplexing.
Abstract: We present a novel optical transmission system to experimentally demonstrate the possibility of mode division multiplexing. Its key components are mode multiplexer and demultiplexer based on a programmable liquid crystal on silicon panel, a prototype few-mode fiber, and a 4x4 multiple input multiple output algorithm processing the information of two polarization diversity coherent receivers. Using this system, we transmit two 100Gb/s PDM-QPSK data streams modulated on two different modes of the prototype few-mode fiber. After 40km, we obtain Q2-factors about 1dB above the limit for forward error correction.

182 citations


Journal ArticleDOI
TL;DR: In this paper, a coherent optical orthogonal frequency-division multiplexing (CO-OFDM) scheme with reduced guard interval (RGI) was proposed for high-speed high-spectral-efficiency long-haul optical transmission.
Abstract: We propose a novel coherent optical orthogonal frequency-division multiplexing (CO-OFDM) scheme with reduced guard interval (RGI) for high-speed high-spectral-efficiency long-haul optical transmission. In this scheme, fiber chromatic dispersion is compensated for within the receiver rather than being accommodated by the guard interval (GI) as in conventional CO-OFDM, thereby reducing the needed GI, especially when fiber dispersion is large. We demonstrate the generation of a 448-Gb/s RGI-CO-OFDM signal with 16-QAM subcarrier modulation through orthogonal band multiplexing. This signal occupies an optical bandwidth of 60 GHz, and is transmitted over 2000 km of ultra-large-area fiber (ULAF) with five passes through an 80-GHz-grid wavelength-selective switch. Banded digital coherent detection with two detection bands is used to receive this 448-Gb/s signal. Wavelength-division multiplexed transmission of three 80-GHz spaced 448-Gb/s RGI-CO-OFDM channels is also demonstrated, achieving a net system spectral efficiency of 5.2 b/s/Hz and a transmission distance of 1600 km of ULAF.

178 citations


Journal ArticleDOI
TL;DR: In this paper, a novel and simple scheme to realize flexible access for gigabit wireline and impulse radio ultrawideband (IR-UWB) wireless services is proposed.
Abstract: In this paper, a novel and simple scheme to realize flexible access for gigabit wireline and impulse radio ultrawideband (IR-UWB) wireless services is proposed. The UWB signals are generated by multi-carrier upconverting and reshaping the baseband signals. The proposed system was experimentally demonstrated with the performances of 2.0-Gb/s data in both baseband and UWB formats after 46-km single mode fiber transmission and further 0.5-m wireless for UWB data. The flexibility of the system is confirmed by investigating the system performance at different data rates including 1.0 and 1.6 Gb/s. Optical wavelength independency and data-rate variability of UWB signal generation makes the system attractive for potential wireline and wireless applications in existing wavelength division multiplexing (WDM)-passive optical network (PON) systems.

178 citations


Journal ArticleDOI
TL;DR: A 4x4 spatially non-blocking Mach-Zehnder based silicon optical switch fabricated using processes fully compatible with standard CMOS successfully demonstrates operation in all 9 unique switch states and 12 possible I/O routing configurations.
Abstract: We present a 4x4 spatially non-blocking Mach-Zehnder based silicon optical switch fabricated using processes fully compatible with standard CMOS. We successfully demonstrate operation in all 9 unique switch states and 12 possible I/O routing configurations, with worst-case cross-talk levels lower than −9 dB, and common spectral bandwidth of 7 nm. High-speed 40 Gbps data transmission experiments verify optical data integrity for all input-output channels.

164 citations


Journal ArticleDOI
Peter J. Winzer1
TL;DR: In this paper, the role of parallel transport options such as spatial multiplexing or multiband transmission in the capacity scaling of optical transport systems is discussed, and it is shown that a system supporting 20 b/s/Hz over 1500 km can be about 100 times more energy efficient than when it is built using a single waveguide at high capacity.
Abstract: We discuss the role of parallel transport options such as spatial multiplexing or multiband transmission in the capacity scaling of optical transport systems. Taking current experimental spectral efficiency records as a baseline, a system supporting 20 b/s/Hz over 1500 km can be about 100 times more energy efficient when it is built using spatial multiplexing than when it is built using a single waveguide at high capacity.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the generation, wavelength-division-multiplexed (WDM) longhaul transmission, and coherent detection of 224-Gb/s PIMO 16-ary quadrature amplitude modulation (16-QAM) at a line rate of 28 Gbaud.
Abstract: We discuss the generation, wavelength-division-multiplexed (WDM) long-haul transmission, and coherent detection of 224-Gb/s polarization-division-multiplexed (PDM) 16-ary quadrature amplitude modulation (16-QAM) at a line rate of 28 Gbaud. We measure a required optical signal-to-noise ratio of 23.4 dB (0.1-nm reference bandwidth; 10-3 bit-error ratio), 3.4-dB off the theoretical limit. Using ultra-large-area fiber, we achieve 2000-km single-channel transmission. We also demonstrate 1200-km WDM transmission on a 50-GHz grid (4-b/s/Hz spectral efficiency), including three passes through a wavelength-selective switch.

Proceedings ArticleDOI
06 Mar 2011
TL;DR: In this article, the authors demonstrate record 109-Tb/s transmission of spatial division multiplexed (SDM) signals over 16.8 km using a seven-core fiber.
Abstract: We demonstrate record 109-Tb/s transmission of spatial division multiplexed (SDM) signals over 16.8 km using a seven-core fiber. Each SDM channel contains 97 WDM channels on a 100-GHz grid and 2×86-Gb/s polarization-multiplexed QPSK signals.

Journal ArticleDOI
TL;DR: In the encoding process, conventional algorithm employed for the generation of collinearly superimposed OVs is combined with a genetic algorithm to achieve high-volume OV multiplexing to increase the number of signal channels in free-space optical communication.
Abstract: We report an approach to the increase of signal channels in free-space optical communication based on composed optical vortices (OVs). In the encoding process, conventional algorithm employed for the generation of collinearly superimposed OVs is combined with a genetic algorithm to achieve high-volume OV multiplexing. At the receiver end, a novel Dammann vortex grating is used to analyze the multihelix beams with a large number of OVs. We experimentally demonstrate a digitized system which is capable of transmitting and receiving 16 OV channels simultaneously. This system is expected to be compatible with a high-speed OV multiplexing technique, with potentials to extremely high-volume information density in OV communication.

Proceedings ArticleDOI
18 Sep 2011
TL;DR: In this paper, the design and fabrication of a few-mode fiber that supports 4 robust modes with low mode couplings, large differential group delays, large effective areas of similar values, and low losses is described.
Abstract: We report the design and fabrication of a few-mode fiber that supports 4 robust modes with low mode couplings, large differential group delays, large effective areas of similar values, and low losses.

Proceedings ArticleDOI
06 Mar 2011
TL;DR: A general policy to allocate subcarriers to time-varying traffic in a flexible OFDM optical network is proposed and the OFDM network performance is compared to that of a fixed-grid WDM network using simulations.
Abstract: We propose a general policy to allocate subcarriers to time-varying traffic in a flexible OFDM optical network. We compare the OFDM network performance to that of a fixed-grid WDM network using simulations.

Journal ArticleDOI
Eugen Lach1, Wilfried Idler1
TL;DR: In this paper, the modulation formats for serial optical transmission of 100-Gbit/s and beyond are reviewed. And the main characteristics of modulation formats and application areas of transport technologies for future networks are discussed.

Proceedings ArticleDOI
06 Mar 2011
TL;DR: In this article, a filterless coherent PON with channel spacing down to 2.8 GHz and real-time processing in an FPGA is demonstrated and verified experimentally using SSB generation at the OLT and fully integrated ONU transceivers.
Abstract: A filterless coherent PON with channel spacing down to 2.8 GHz and real-time processing in an FPGA is demonstrated. 64-channel operation is verified experimentally using SSB generation at the OLT and fully integrated ONU transceivers.

Journal ArticleDOI
TL;DR: It is shown that the launch power maximizing capacity is independent of link length and modulation format, and the usable range of PM-QAM systems is discussed.
Abstract: Based on a recently introduced model of non-linear propagation, we propose analytical formulas for the capacity limit of polarization-multiplexed ultra-dense WDM uncompensated coherent optical systems at the Nyquist limit, assuming both lumped and ideally distributed amplification. According to these formulas, capacity fundamentally depends on the transmitted power spectral density and on the total optical WDM bandwidth, whereas it does not depend on symbol-rate. Also, capacity approximately decreases by 2 [bit/s/Hz] for every doubling of link length. We show examples of capacity calculations for specific ultra-long-haul links with different polarization-multiplexed (PM) constellations, i.e. ideal PM-Gaussian, PM-QPSK (quadrature-phase shift keying) and PM-QAM (quadrature amplitude modulation). We show that the launch power maximizing capacity is independent of link length and modulation format. We also discuss the usable range of PM-QAM systems and validate analysis with simulations.

Proceedings ArticleDOI
18 Sep 2011
TL;DR: In this article, the LP 01 and LP 11 modes of a few-mode fiber were used to demonstrate mode-division multiplexed WDM transmission using a 6×6 MIMO equalizer at the receiver after amplification by a fewmode EDFA.
Abstract: We demonstrate mode-division multiplexed WDM transmission using the LP 01 and LP 11 modes of a few-mode fiber. The signal is recovered using a 6×6 MIMO equalizer at the receiver after amplification by a few-mode EDFA.

Proceedings ArticleDOI
18 Sep 2011
TL;DR: Mode-division multiplexing is demonstrated over five modes for the first time over 40km few-mode fiber, demultiplexed, and successfully recovered.
Abstract: Mode-division multiplexing is demonstrated over five modes for the first time. Five data streams are modulated at 100Gb/s with PDM-QPSK modulation format, multiplexed altogether, transported over 40km few-mode fiber, demultiplexed, and successfully recovered.

Journal ArticleDOI
TL;DR: A 16-channel 200 GHz arrayed-waveguide grating (AWG) (de)-multiplexer is demonstrated experimentally by utilizing Si3N4 buried optical waveguides, which have 50 nm-thick Si3n4 cores and a 15 μm-th thickness cladding.
Abstract: A 16-channel 200 GHz arrayed-waveguide grating (AWG) (de)-multiplexer is demonstrated experimentally by utilizing Si3N4 buried optical waveguides, which have 50 nm-thick Si3N4 cores and a 15 μm-thick SiO2 cladding. The structure with an ultra-thin core layer helps to reduce the scattering due to the sidewall roughness and consequently shows very low loss of about 0.4~0.8 dB/m. When using this type of optical waveguide for an AWG (de)multiplexer, there is no problem associated with gap refill using the upper-cladding material even when choosing a small (e.g., 1.0 μm) gap between adjacent arrayed waveguides, which helps to reduce the transition loss between the FPR (free-propagation region) and the arrayed waveguides. Therefore, the demonstrated AWG (de)multiplexer based on the present Si3N4 buried optical waveguides has a low on-chip loss. The fabricated AWG (de)multiplexer is characterized in two wavelength ranges around 1310 nm and 1550 nm, respectively. It shows that the crosstalk from adjacent and non-adjacent channels are about -30 dB, and -40 dB, respectively, at the wavelength range of 1310 nm. The Si3N4 AWG (de)multiplexer has a temperature dependence of about 0.011 nm/°C, which is close to that of a pure SiO2 AWG device.

Proceedings ArticleDOI
14 Mar 2011
TL;DR: A contention-free new architecture based on optical network on chip, called Optical Ring Network-on-Chip (ORNoC), which is capable of connecting 1296 nodes with only 102 waveguides and 64 wavelengths per waveguide and scales well with both large 2D and 3D architectures.
Abstract: State-of-the-art System-on-Chip (SoC) consists of hundreds of processing elements, while trends in design of the next generation of SoC point to integration of thousand of processing elements, requiring high performance interconnect for high throughput communications. Optical on-chip interconnects are currently considered as one of the most promising paradigms for the design of such next generation Multi-Processors System on Chip (MPSoC). They enable significantly increased bandwidth, increased immunity to electromagnetic noise, decreased latency, and decreased power. Therefore, defining new architectures taking advantage of optical interconnects represents today a key issue for MPSoC designers. Moreover, new design methodologies, considering the design constraints specific to these architectures are mandatory. In this paper, we present a contention-free new architecture based on optical network on chip, called Optical Ring Network-on-Chip (ORNoC). We also show that our network scales well with both large 2D and 3D architectures. For the efficient design, we propose automatic wavelength-/waveguide assignment and demonstrate that the proposed architecture is capable of connecting 1296 nodes with only 102 waveguides and 64 wavelengths per waveguide.

Proceedings ArticleDOI
06 Mar 2011
TL;DR: In this article, the intrinsic Grid-free capabilities of LCOS and how it can be used practically in a flexible Grid architecture to maximize total fiber capacity are discussed. But the authors focus on the grid-free capability of the optical traffic.
Abstract: The increasing spectral efficiency of Optical Transmission systems is constrained by the limitations of wavelength switching and is driving a requirement for significantly more flexible approaches to routing of the optical traffic. We present the intrinsic Grid-free capabilities of LCOS and show how it can be used practically in a flexible Grid architecture to maximize total fiber capacity.

Proceedings ArticleDOI
18 Sep 2011
TL;DR: A routing and spectrum assignment algorithm for elastic optical networks that achieves high utilization of spectrum resources by considering the consecutiveness of common available spectrum slots among relevant fibers is proposed.
Abstract: This paper proposes a routing and spectrum assignment algorithm for elastic optical networks. The algorithm achieves high utilization of spectrum resources by considering the consecutiveness of common available spectrum slots among relevant fibers.

Journal ArticleDOI
TL;DR: This paper demonstrates successful transmission of 107-Gb/s dual-mode and dual-polarization coherent optical orthogonal frequency-division multiplexing (CO-OFDM) over a 4.5-km two-mode fiber.
Abstract: In addition to the dimensions of time, frequency, complex constellation, and polarization, spatial mode can be the fifth dimension to be explored for modulation and multiplexing in optical fiber communications. In this paper, we demonstrate successful transmission of 107-Gb/s dual-mode and dual-polarization coherent optical orthogonal frequency-division multiplexing (CO-OFDM) over a 4.5-km two-mode fiber. A mechanically-induced LP01/LP11 mode converter is used as the mode selective element in a spatial-mode multiplexed system.

Journal ArticleDOI
TL;DR: In this paper, a novel high-speed optical wireless communication system incorporating wavelength division multiplexing technology for indoor personal area networking applications is proposed, which can achieve bit rate as high as 4 × 12.5 Gb/s.
Abstract: A novel high-speed optical wireless communication system incorporating wavelength division multiplexing technology for indoor personal area networking applications is proposed in this paper. Even with the simplest single wide field-of-view (45°) nonimaging receiver, bit rate as high as 4 × 12.5 Gb/s has been successfully demonstrated by experiments. It is shown that error-free reception (bit error rate <; 10-9) can be achieved over the entire beam footprint of about 1 m, so limited mobility can be provided to subscribers. In addition, a new localization system based on this optical wireless communication system has also been proposed and verified by experiments. When these two systems are incorporated together, high-speed optical wireless communication with mobility feature can be provided to users over the entire room.

Journal ArticleDOI
TL;DR: It is demonstrated that even under strong nonlinear distortion the transmission reach only reduces by a factor of ~2.5 for a 2 unit increase in capacity when full band DBP is employed, in proportion to the required back-to-back OSNR.
Abstract: We report the performance of coherently-detected nine-channel WDM transmission over high dispersion fibers, using polarization multiplexed m-ary quadrature amplitude modulation (m = 4, 16, 64, 256) at 112 Gbit/s. Compensation of fiber nonlinearities via digital back-propagation enables up to 10 dB improvement in maximum transmittable power and similar to 8 dB Q(eff) improvement which translates to a nine-fold enhancement in transmission reach for PM-256QAM, where the largest improvements are associated with higher-order modulation formats. We further demonstrate that even under strong nonlinear distortion the transmission reach only reduces by a factor of similar to 2.5 for a 2 unit increase in capacity (log(2)m) when full band DBP is employed, in proportion to the required back-to-back OSNR.

Journal ArticleDOI
TL;DR: In this paper, the authors provide a comprehensive probabilistic analysis of the capacity (maximum mean packet throughput) and packet delay of subnetworks that can be used to form NG-PONs.
Abstract: Building on the Ethernet Passive Optical Network (EPON) and Gigabit PON (GPON) standards, Next-Generation (NG) PONs (i) provide increased data rates, split ratios, wavelengths counts, and fiber lengths, as well as (ii) allow for all-optical integration of access and metro networks. In this paper we provide a comprehensive probabilistic analysis of the capacity (maximum mean packet throughput) and packet delay of subnetworks that can be used to form NG-PONs. Our analysis can cover a wide range of NG-PONs through taking the minimum capacity of the subnetworks forming the NG-PON and weighing the packet delays of the subnetworks. Our numerical and simulation results indicate that our analysis quite accurately characterizes the throughput-delay performance of EPON/GPON tree networks, including networks upgraded with higher data rates and wavelength counts. Our analysis also characterizes the trade-offs and bottlenecks when integrating EPON/GPON tree networks across a metro area with a ring, a Passive Star Coupler (PSC), or an Arrayed Waveguide Grating (AWG) for uniform and non-uniform traffic. To the best of our knowledge, the presented analysis is the first to consider multiple PONs interconnected via a metro network.

Journal ArticleDOI
Hua Lu1, Xueming Liu1, Yongkang Gong1, Dong Mao1, Leiran Wang1 
TL;DR: A novel kind of nanoscale plasmonic wavelength demultiplexing structure based on channel drop filters in metal-insulator-metal waveguide with reflection nanocavities that can find more applications for the ultra-compact WDM systems in highly integrated optical circuits is proposed.
Abstract: We propose and numerically investigate a novel kind of nanoscale plasmonic wavelength demultiplexing (WDM) structure based on channel drop filters in metal-insulator-metal waveguide with reflection nanocavities. By using finite-difference time-domain simulations, it is found that the transmission efficiency of the channel drop filter can be significantly enhanced by selecting the proper distance between the drop and reflection cavities. The result can be exactly analyzed by the temporal coupled-mode theory. According to this principle, a nanoscale triple-wavelength demultiplexer with high drop efficiencies is designed. The proposed structure can find more applications for the ultra-compact WDM systems in highly integrated optical circuits.