ROADM Traversal Improvement Enabled by Optical Domain Equalization

Author(s):  
Zhenhua Feng ◽  
Huan Chen ◽  
Feng Shi ◽  
Yinqiu Jia ◽  
Qiong Wu ◽  
...  
Keyword(s):  
1997 ◽  
Vol 161 ◽  
pp. 267-282 ◽  
Author(s):  
Thierry Montmerle

AbstractFor life to develop, planets are a necessary condition. Likewise, for planets to form, stars must be surrounded by circumstellar disks, at least some time during their pre-main sequence evolution. Much progress has been made recently in the study of young solar-like stars. In the optical domain, these stars are known as «T Tauri stars». A significant number show IR excess, and other phenomena indirectly suggesting the presence of circumstellar disks. The current wisdom is that there is an evolutionary sequence from protostars to T Tauri stars. This sequence is characterized by the initial presence of disks, with lifetimes ~ 1-10 Myr after the intial collapse of a dense envelope having given birth to a star. While they are present, about 30% of the disks have masses larger than the minimum solar nebula. Their disappearance may correspond to the growth of dust grains, followed by planetesimal and planet formation, but this is not yet demonstrated.


2021 ◽  
Vol 11 (5) ◽  
pp. 2081
Author(s):  
Francisco-Javier Moreno-Muro ◽  
Miquel Garrich ◽  
Ignacio Iglesias-Castreño ◽  
Safaa Zahir ◽  
Pablo Pavón-Mariño

Telecom operators’ infrastructure is undergoing high pressure to keep the pace with the traffic demand generated by the societal need of remote communications, bandwidth-hungry applications, and the fulfilment of 5G requirements. Software-defined networking (SDN) entered in scene decoupling the data-plane forwarding actions from the control-plane decisions, hence boosting network programmability and innovation. Optical networks are also capitalizing on SDN benefits jointly with a disaggregation trend that holds the promise of overcoming traditional vendor-locked island limitations. In this work, we present our framework for disaggregated optical networks that leverages on SDN and container-based management for a realistic emulation of deployment scenarios. Our proposal relies on Kubernetes for the containers’ control and management, while employing the NETCONF protocol for the interaction with the light-weight software entities, i.e., agents, which govern the emulated optical devices. Remarkably, our agents’ structure relies on components that offer high versatility for accommodating the wide variety of components and systems in the optical domain. We showcase our proposal with the emulation of an 18-node European topology employing Cassini-compliant optical models, i.e., a state-of-the-art optical transponder proposed in the Telecom Infrastructure Project. The combination of our versatile framework based on containerized entities, the automatic creation of agents and the optical-layer characteristics represents a novel approach suitable for operationally complex carrier-grade transport infrastructure with SDN-based disaggregated optical systems.


2021 ◽  
Vol 7 (18) ◽  
pp. eabf1959
Author(s):  
Ji Hao ◽  
Young-Hoon Kim ◽  
Severin N. Habisreutinger ◽  
Steven P. Harvey ◽  
Elisa M. Miller ◽  
...  

Long-lived photon-stimulated conductance changes in solid-state materials can enable optical memory and brain-inspired neuromorphic information processing. It remains challenging to realize optical switching with low-energy consumption, and new mechanisms and design principles giving rise to persistent photoconductivity (PPC) can help overcome an important technological hurdle. Here, we demonstrate versatile heterojunctions between metal-halide perovskite nanocrystals and semiconducting single-walled carbon nanotubes that enable room-temperature, long-lived (thousands of seconds), writable, and erasable PPC. Optical switching and basic neuromorphic functions can be stimulated at low operating voltages with femto- to pico-joule energies per spiking event, and detailed analysis demonstrates that PPC in this nanoscale interface arises from field-assisted control of ion migration within the nanocrystal array. Contactless optical measurements also suggest these systems as potential candidates for photonic synapses that are stimulated and read in the optical domain. The tunability of PPC shown here holds promise for neuromorphic computing and other technologies that use optical memory.


2019 ◽  
Vol 116 (40) ◽  
pp. 19848-19856 ◽  
Author(s):  
Alexandre Goy ◽  
Girish Rughoobur ◽  
Shuai Li ◽  
Kwabena Arthur ◽  
Akintunde I. Akinwande ◽  
...  

We present a machine learning-based method for tomographic reconstruction of dense layered objects, with range of projection angles limited to ±10○. Whereas previous approaches to phase tomography generally require 2 steps, first to retrieve phase projections from intensity projections and then to perform tomographic reconstruction on the retrieved phase projections, in our work a physics-informed preprocessor followed by a deep neural network (DNN) conduct the 3-dimensional reconstruction directly from the intensity projections. We demonstrate this single-step method experimentally in the visible optical domain on a scaled-up integrated circuit phantom. We show that even under conditions of highly attenuated photon fluxes a DNN trained only on synthetic data can be used to successfully reconstruct physical samples disjoint from the synthetic training set. Thus, the need for producing a large number of physical examples for training is ameliorated. The method is generally applicable to tomography with electromagnetic or other types of radiation at all bands.


2006 ◽  
Author(s):  
Dharmpal Takhar ◽  
Jason N. Laska ◽  
Michael B. Wakin ◽  
Marco F. Duarte ◽  
Dror Baron ◽  
...  

2007 ◽  
Vol 46 (7) ◽  
pp. 070502
Author(s):  
Hongwei Chen
Keyword(s):  

2021 ◽  
Author(s):  
Yunkun Li ◽  
Tao Pu ◽  
Jilin Zheng ◽  
Peng Xiang ◽  
Jin Li ◽  
...  

2021 ◽  
pp. 23-132
Author(s):  
Debasish Datta

The technologies used in optical networks have evolved seamlessly over the past six decades. Optical fibers with extremely low loss and enormous bandwidth are used as the transmission medium, while semiconductor lasers and LEDs serve as optical sources, and the photodetectors – pin and avalanche photodiodes – are used to receive the optical signal at the destination nodes. The transmitted optical signal has to pass through a variety of network elements, which in turn need a wide range of passive and active devices, carrying out the necessary networking functionalities. For WDM optical networks, many of these tasks need to be accomplished in the optical domain itself in a wavelength-selective manner, calling for various types of WDM-based networking elements. In this chapter, we present a comprehensive description of the optical and optoelectronic devices that are used in today’s optical networks. (137 words)


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