scholarly journals Integrated five-port non-blocking optical router based on mode-selective property

Nanophotonics ◽  
2018 ◽  
Vol 7 (5) ◽  
pp. 853-858 ◽  
Author(s):  
Hao Jia ◽  
Ting Zhou ◽  
Xin Fu ◽  
Jianfeng Ding ◽  
Lei Zhang ◽  
...  

AbstractIn this paper, we propose and demonstrate a five-port optical router based on mode-selective property. It utilizes different combinations of four spatial modes at input and output ports as labels to distinguish its 20 routing paths. It can direct signals from the source port to the destination port intelligently without power consumption and additional switching time to realize various path steering. The proposed architecture is constructed by asymmetric directional coupler based mode-multiplexers/de-multiplexers, multimode interference based waveguide crossings and single-mode interconnect waveguides. The broad optical bandwidths of these constituents make the device suitable to combine with wavelength division multiplexing signal transmission, which can effectively increase the data throughput. Measurement results show that the insertion loss of its 20 routing paths are lower than 8.5 dB and the optical signal-to-noise ratios are larger than 16.3 dB at 1525–1565 nm. To characterize its routing functionality, a 40-Gbps data transmission with bit-error-rate (BER) measurement is implemented. The power penalties for the error-free switching (BER<10−9) are 1.0 dB and 0.8 dB at 1545 nm and 1565 nm, respectively.

Dense wavelength division multiplexing is used in various broadband communications. It combines information from distinct sources on an optical fiber, each signal being transmitted simultaneously on its own distinct light wavelength. Radio over fibre is a hybrid system that has both fibre optic link and free space radio path. This paper aims to evaluate the performance of the system using Erbium Doped Fibre Amplifier, Single Mode Fibre and Dispersion compensating Fibre. Single beam of light is passed by the SMF and is used for long distance signal transmission. DCF is used to reduce the dispersion in the optical signal. EDFA reduces the degradation of the signal by cancelling the effect of attenuation. It is an optical repeater used to raise the intensity of the optical signal. Mach – Zehnder modulator is used for the modulation. The simulation is carried out by using optisystem software version 15.0. Various parameters like Q-factor, BER pattern, threshold, minimum BER are compared and estimated.


2021 ◽  
Vol 9 ◽  
Author(s):  
Daniel A. Nolan ◽  
Dan T. Nguyen

The capacity of optical fiber communications has grown exponentially since its implementation decades ago. Optical fiber amplifiers, wavelength division multiplexing, and coherent communications have all enabled discontinuous growth. Space division multiplexing is proposed as the next discontinuity. Here tens of modes rather than a single mode are utilized in the transmission. Random scattering due to index fluctuations within the optical fiber cause coupling among the modal channels thereby degrading signal transmission. Principal mode transmission overcomes this limitation. Here a set of modes arrive localized at the fiber output unscattered. We review this methodology as it relates to optical communication capacity, but also as it relates to light localization. We also review the characterization of these modes both theoretically and experimentally.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Georg Rademacher ◽  
Benjamin J. Puttnam ◽  
Ruben S. Luís ◽  
Tobias A. Eriksson ◽  
Nicolas K. Fontaine ◽  
...  

AbstractData rates in optical fiber networks have increased exponentially over the past decades and core-networks are expected to operate in the peta-bit-per-second regime by 2030. As current single-mode fiber-based transmission systems are reaching their capacity limits, space-division multiplexing has been investigated as a means to increase the per-fiber capacity. Of all space-division multiplexing fibers proposed to date, multi-mode fibers have the highest spatial channel density, as signals traveling in orthogonal fiber modes share the same fiber-core. By combining a high mode-count multi-mode fiber with wideband wavelength-division multiplexing, we report a peta-bit-per-second class transmission demonstration in multi-mode fibers. This was enabled by combining three key technologies: a wideband optical comb-based transmitter to generate highly spectral efficient 64-quadrature-amplitude modulated signals between 1528 nm and 1610 nm wavelength, a broadband mode-multiplexer, based on multi-plane light conversion, and a 15-mode multi-mode fiber with optimized transmission characteristics for wideband operation.


Author(s):  
K. Ishikawa ◽  
Q. Yu

An integrated arrayed waveguide grating multi/demultiplexer (AWG) with a micro-electro-mechanical systems (MEMS) based variable optical attenuator (VOA) is reported. The device consists of an AWG based on silica and a MEMS-VOA chip. The MEMS chip includes 100 μm × 100 μm polysilicon shutter plates coated with gold and electrostatic comb-drive actuators. The MEMS chip is interposed in a trench located in the middle of the I/O waveguides of the AWG to tune the optical transmitting power intensity through the waveguides continuously. The MEMS-VOA shutters have more than a 10 μm displacement. Using those shutters, 30 dB optical contrast from 5 dB at the transmit state to 35 dB at the isolation state is achieved. The obtained attenuation contrast is greater than that of a conventional waveguide-based Mach-Zehnder interferometer VOA and sufficient to adjust and equalize the optical signal power in the wavelength division multiplexing (WDM) network systems.


2021 ◽  
Author(s):  
Alireza Cheshmberah ◽  
Mahmood Seifouri ◽  
Saeed Olyaee

Abstract Supercontinuum spectrum generation is a process in which laser beam in femtoseconds and high power (kilowatts) is converted into a broad-spectrum beam of light after passing through a specific environment. Of course, achieving this range comes with many limitations. In this paper, photonic crystal fibers are used as a substrate for input pulse due to the ability to control dispersion and loss, and creating single-mode operating conditions. One of the main factors for the formation of supercontinuum spectra of injection pulses is maintaining the nonlinear performance of this type of fiber by controlling the effective mode area and also using chalcogenides (nonlinear coefficients about 100 times higher than silica) in their structure. In the proposed structure, a photonic crystal fiber with silica base element and air cavities with hexagonal structure with the center of Ge11.5As24Se64.5 chalcogenide element have been used to provide the nonlinear property of the structure. Also, in this structure, a ring of Ge20Sb15Se65 chalcogenide elements has been used to reduce the effective mode region and create a flat dispersion curve at a wavelength of 1300 nm (second telecommunication window). The input pulse power is 10 kW and its width is 50 femtoseconds, which has caused the range of the supercontinuum from 800 nm to 1900 nm. This structure can be used to provide the required wavelengths as a carrier in a wavelength division multiplexing (WDM).


Author(s):  
Anurupa Lubana ◽  
Sanmukh Kaur

In this paper, we present a novel erbium–ytterbium doped fiber amplifier (EYDFA) + Raman + EYDFA hybrid optical amplifier (HOA) for a super-dense wavelength division multiplexing (SD-WDM) system application. The performance of the 100-channel system has been investigated for an overall data rate and channel spacing of 100[Formula: see text]Gb/s and 0.4[Formula: see text]nm, respectively, over a wavelength span of 1550–1589.9[Formula: see text]nm. HOA has been optimized for Raman length, EYDFA lengths, pump powers and Er[Formula: see text] concentrations to achieve high average gain and low gain variation ratio of 40.41[Formula: see text]dB and 0.40[Formula: see text]respectively. The optimized configuration of the proposed HOA has been compared with EYDFA + Raman and Raman + EYDFA HOA configurations. The achieved high and flat gain with an acceptable output optical signal to noise ratio (OSNR) in case of EYDFA + Raman + EYDFA HOA; makes it an optimum choice for SD-WDM systems.


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