Results 1 - 10
of
17
A M Saleh, Optical Networking: Past, Present, and Future
- IEEE J Lightwave Tech
"... Abstract—Over the past 25 years, networks have evolved from being relatively static with fairly homogeneous traffic to being more configurable and carrying a heterogeneous array of services. As the applications are ultimately the driver of network evolution, the paper begins with a brief history of ..."
Abstract
-
Cited by 25 (0 self)
- Add to MetaCart
(Show Context)
Abstract—Over the past 25 years, networks have evolved from being relatively static with fairly homogeneous traffic to being more configurable and carrying a heterogeneous array of services. As the applications are ultimately the driver of network evolution, the paper begins with a brief history of circuit, packet, and wave services, along with the development of the corresponding transport layers. The discussion then moves to the evolution of network-node architecture, with an emphasis on the optical-electrical-optical and optical-bypass paradigms. Scalability and cost-effectiveness in meeting network demands are two key factors in the discussion. The evolution of networking equipment, along with the development of the optical control plane, has facilitated a configurable optical layer. The enabling technologies, along with their ramifications, are discussed. Finally, the paper speculates on how capacity might evolve in the future, to handle the undoubtedly new services that are on the horizon. Index Terms—Configurability, dynamic networks, network evolution, network services, network transport layers, optical bypass, optical network elements, optical networking. I.
Dispersion enhancement and linearization in a dynamic DWDM channel blocker
- J. Lightw. Technol
"... Abstract—A dynamic dense-wavelength-division-multiplexing (DWDM) channel blocker and equalizer is developed based on liquid crystal (LC) and dispersion control technology. A multipixel LC array is adopted to regulate the power level of each DWDM channel, while a reflective grating diffracts the inpu ..."
Abstract
-
Cited by 2 (1 self)
- Add to MetaCart
Abstract—A dynamic dense-wavelength-division-multiplexing (DWDM) channel blocker and equalizer is developed based on liquid crystal (LC) and dispersion control technology. A multipixel LC array is adopted to regulate the power level of each DWDM channel, while a reflective grating diffracts the input signals spatially to corresponding LC pixels. A dispersion control unit is proposed and employed to enhance the dispersion and compensate the intrinsic nonlinear dispersion of the grating. Therefore, all LC pixels could handle corresponding lights centered at the Interna-tional Telecommunications Union Grids. A 40-channel, 100-GHz channel-spacing dynamic wavelength blocker/equalizer is thus demonstrated with dB insertion loss and over 40 dB extinction ratio. The maximum center frequency shift of all 40 channels is GHz, which means our dispersion control technology works very well for grating-based DWDM devices. Index Terms—Diffraction gratings, fiber optics components, liquid crystal (LC) devices, multiplexing. I.
Elastomer based tunable optofluidic devices
- Lab Chip 2012
"... The synergetic integration of photonics and microfluidics has enabled a wide range of optofluidic devices that can be tuned based on various physical mechanisms. One such tuning mechanism can be realized based on the elasticity of polydimethylsiloxane (PDMS). The mechanical tuning of these optofluid ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
The synergetic integration of photonics and microfluidics has enabled a wide range of optofluidic devices that can be tuned based on various physical mechanisms. One such tuning mechanism can be realized based on the elasticity of polydimethylsiloxane (PDMS). The mechanical tuning of these optofluidic devices was achieved by modifying the geometry of the device upon applying internal or external forces. External or internal forces can deform the elastomeric components that in turn can alter the optical properties of the device or directly induce flow. In this review, we discuss recent progress in tunable optofluidic devices, where tunability is enabled by the elasticity of the construction material. Different subtypes of such tuning methods will be summarized, namely tuning based on bulk or membrane deformations, and pneumatic actuation. 1.
ABSTRACT Title of Document: FABRICATION AND PROCESS DEVELOPMENT FOR AN INTEGRATED OPTICAL MEMS MICROSYSTEM IN
"... This dissertation presents the design, fabrication, and evaluation of the first monolithically integrated MEMS resonant sensor system realized in the InP-InGaAs material family. The integration of a MEMS sensor along with the facilitating optical interrogation platform provides for increased manufac ..."
Abstract
- Add to MetaCart
(Show Context)
This dissertation presents the design, fabrication, and evaluation of the first monolithically integrated MEMS resonant sensor system realized in the InP-InGaAs material family. The integration of a MEMS sensor along with the facilitating optical interrogation platform provides for increased manufacturing scalability, sensitivity, and reduced measurement noise and device cost. The MEMS device presented in this dissertation consists of an Indium Phosphide (InP) cantilever waveguide resonator whose displacement is measured optically via a vertically integrated laser diode and waveguide photodetector. All three major components of the sensor were integrated in a single 7.1 µm thick molecular beam epitaxy (MBE) epitaxial growth, lattice matched to an InP substrate. Full fabrication of the integrated MEMS device utilizes 7 projection lithography masks, 4 nested inductively coupled plasma (ICP) etches, and over 60 discrete processing steps. This dissertation focuses on the integration design and the development of specific III-V semiconductor fabrication processes in order to completely fabricate and realize these devices, including specialized ICP etching steps and a MEMS undercutting release etch. The fabricated devices were
MICROFABRICATION TECHNOLOGIES BASED ON ELECTRO-DISPENSING
"... ABSTRACT A microfabrication technology with real-time polymer processing control is introduced in this work. The technique is titled electro-dispensing, as it employs a metal microdispensing tip that is biased with a user-defined voltage. The insitu voltage directs an electric field through the und ..."
Abstract
- Add to MetaCart
(Show Context)
ABSTRACT A microfabrication technology with real-time polymer processing control is introduced in this work. The technique is titled electro-dispensing, as it employs a metal microdispensing tip that is biased with a user-defined voltage. The insitu voltage directs an electric field through the underlying dispensed polymer structure. Polymer droplets are dispensed directly onto a chip with precise (pL) volumes, and the in-situ micro-dispensing tip voltage is varied to adjust the polymer droplet morphology during the microfabrication process. The technique is carried out within a glycerol ambient filler solution, to create an initial high contact angle (160°) on the polymer microdroplets, and voltage tunability is applied to control the microdroplet shapes. Ultraviolet curing is subsequently employed to solidify the micro-spheroid structures on the desired locations across the chip. The electrodispensing process is demonstrated in this work for numerous microdroplets, with a variety of polymer morphologies and diameters down to 150 µm. The capabilities of the electro-dispensing process are also demonstrated in this work for a specific application relating to integrated photonic circuitry. Polymer microdroplets in the past have been limited to use as lenses for vertical beam focusing (through the plane of the chip), because of their exceedingly low contact angles on solid surfaces. In this work, polymer micro-droplets are introduced for lateral beam focusing and retroreflection (above and parallel to the plane of the chip). These new technologies for on-chip optical beam dispersion management are brought about by the capabilities of electrodispensing: the use of an ambient filler allows the dispensing process to create high-contact-angle near-spherical microdroplets; the electro-dispensing process then allows this droplet to be tuned for its specific role within the integrated photonic chip (e.g. as a spherical element for in-plane focusing or an elliptical element for in-plane retroreflection). Ray-based analyses and electromagnetic models are used to characterize the optical responses of the micro-spheroid structures, and the results are compared to experimental measurements with onchip laser beam control.
Optical Switching and Networking (2011) 1 Comparison in Power Consumption of Static and Dynamic WDM Networks
"... Abstract — Greening of the Internet has become one of the main challenges for the research community. Optical networks can provide an energy efficient solution, but it has become crucial to assess its power efficiency. In this context, dynamic operation of WDM networks is expected to provide signifi ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract — Greening of the Internet has become one of the main challenges for the research community. Optical networks can provide an energy efficient solution, but it has become crucial to assess its power efficiency. In this context, dynamic operation of WDM networks is expected to provide significant power savings when compared to static operation; however, its benefits need to be evaluated to determine its actual impact and to analyze future trends. In this paper, a general framework for evaluating energy consumption in WDM networks is introduced. The proposed framework enables the analysis of different node architectures, link capacities and network topologies. In particular, the case of three different node architectures is discussed and compared. Results show that dynamic operation can significantly reduce power consumption when either the traffic load is below 0.4 or when short reach transponders consume significantly lower power than long reach ones. In the latter case, dynamic operation shows significant benefits compared to the static case for traffic loads higher than 0.4. It is also shown that the transponders of the input/output stage of the nodes determine the benefit –in terms of power consumption- of an eventual migration from static to dynamic architecture rather than the transponders of the interface between the WDM and higher layers. Index Terms — Optical networks, energy efficiency, power consumption.
Frame-Scheduling for Input-Queued Switches with Energy Reconfiguration Costs
"... Abstract—We consider a slotted input-queued switch with a crossbar-like switching fabric. In each time-slot, a centralized scheduler determines a switching fabric configuration to transfer packets. We consider the energy consumption needed to configure the switching fabric and we assume that the ene ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract—We consider a slotted input-queued switch with a crossbar-like switching fabric. In each time-slot, a centralized scheduler determines a switching fabric configuration to transfer packets. We consider the energy consumption needed to configure the switching fabric and we assume that the energy depends on the number of modifications in the switching configuration in two consecutive time-slots. We address the problem of scheduling a set of packets to minimize the required energy while preserving high throughput. We reduce the overall problem to the combination of two different optimization problems. We propose a family of algorithms to solve the problem and we discuss their energythroughput performance. I.
permission. Tunable Optical Microresonators with Micro-Electro-Mechanical-System (MEMS) Integration
"... All rights reserved. ..."
(Show Context)
Acknowledgements
"... This study was a collaborative effort by a team of researchers, practitioners and graduate students. We would like to thank all members involved for their efforts and suggestions. Project Team Members: ..."
Abstract
- Add to MetaCart
(Show Context)
This study was a collaborative effort by a team of researchers, practitioners and graduate students. We would like to thank all members involved for their efforts and suggestions. Project Team Members:
1 Multi-hop Scheduling Algorithms in Switches with Reconfiguration Latency
"... Optical switching fabrics (OSFs) are receiving increasing attention in the design of high speed packet switches, due to their excellent properties in terms of available bandwidth and reduced power consumption. However, most optical devices require a reconfiguration latency each time input/output swi ..."
Abstract
- Add to MetaCart
(Show Context)
Optical switching fabrics (OSFs) are receiving increasing attention in the design of high speed packet switches, due to their excellent properties in terms of available bandwidth and reduced power consumption. However, most optical devices require a reconfiguration latency each time input/output switch port connections are modified. This latency may not be negligible with respect to the packet transmission time, and can adversely affect switch performance, creating high delays and reduced throughput. In this paper we consider OSFs and we propose a multi-hop approach to schedule packet transfer, i.e., packets are sent to the final destination port exploiting transmission through intermediate ports. We show that the multi-hop approach is a promising technique to control the trade-off between delay and throughput. We propose a general framework to solve the issue of multi-hop transmission in IQ packet switches. Furthermore, we examine the multi-hop approach when using logical interconnections among ports based on multi-dimensional regular topologies. We discuss the switch scheduling problem, and the design of routing and queueing schemes. Performance are analyzed both analytically and by simulation. I.
