The Experts below are selected from a list of 35205 Experts worldwide ranked by ideXlab platform
G Lenz - One of the best experts on this subject based on the ideXlab platform.
-
Optical delay lines based on Optical Filters
IEEE Journal of Quantum Electronics, 2001Co-Authors: G Lenz, Christi K. Madsen, Benjamin J. Eggleton, Richard E. SlusherAbstract:Optical delay lines have some important applications, notably in Optical communication systems and in phased arrays. These devices are based on the concept of Optical group delay, which, in turn, can be understood as the property of an Optical filter. Optical Filters are well-understood devices and, in particular, their dispersive properties determine the group delay response. We review these dispersive properties and point out some of the inherent tradeoffs involved in generating large group delay. Fiber Bragg gratings and recent results on Optical all-pass Filters are used as examples.
-
Dispersive properties of Optical Filters for WDM systems
IEEE Journal of Quantum Electronics, 1998Co-Authors: G Lenz, Benjamin John Eggleton, Clinton Randy Giles, Christi K. Madsen, Richart Elliott SlusherAbstract:Wavelength division multiplexing (WDM) communication systems invariably require good Optical Filters meeting stringent requirements on their amplitude response, the ideal being a perfectly rectangular filter. To achieve high bandwidth utilization, the phase response of these Filters is of equal importance, with the ideal filter having perfectly linear phase and therefore constant time delay and no dispersion. This aspect of Optical Filters for WDM systems has not received much attention until very recently. It is the objective of this paper to consider the phase response and resulting dispersion of Optical Filters in general and their impact on WDM system performance. To this end we use general concepts from linear systems, in particular, minimum and nonminimum phase response and the applicability of Hilbert transforms (also known as Kramers-Kronig relations). We analyze three different classes of Optical Filters, which are currently being used in WDM systems and compare their performance in terms of their phase response. Finally, we consider possible ways of linearizing the phase response without affecting the amplitude response, in an attempt to approximate the ideal filter and achieve the highest bandwidth utilization.
-
Optical all pass Filters for phase response design with applications for dispersion compensation
IEEE Photonics Technology Letters, 1998Co-Authors: C K Madsen, G LenzAbstract:Lossless all-pass Optical Filters are introduced, which can approximate any desired phase response while maintaining a constant, unity amplitude response. Architectures using cascade and lattice structures based on ring resonators and cavities defined by reflectors are discussed. Two applications are presented: 1) for fiber dispersion compensation and 2) for compensation of the nonlinear phase response of narrow bandpass Optical Filters such as thin-film or Bragg grating Filters. All orders of dispersion can be compensated in principle, and the Filters are periodic so multiple channels can be compensated with a single device. The architectures are very compact compared to alternatives such as chirped Bragg gratings.
-
Optimal dispersion of Optical Filters for WDM systems
IEEE Photonics Technology Letters, 1998Co-Authors: G Lenz, Benjamin John Eggleton, Clinton Randy Giles, Christi K. Madsen, G. NykolakAbstract:The phase response of Optical Filters determines their dispersive properties and impacts wavelength-division multiplexing (WDM) system performance. We present a general analysis of the phase response of Optical Filters used in WDM systems and suggest ways to minimize the detrimental dispersive effects of these Filters. Some Filters are found to be inherently linear phase Filters and in principle are dispersionless. We also show that some Filters may be realized for the phase correction of dispersive Filters. Experimental system results demonstrate the negative effects of filter dispersion on system performance.
Le Nguyen Binh - One of the best experts on this subject based on the ideXlab platform.
-
realization of first order monotonic butterworth type low pass and high pass Optical Filters experimental verification
Microwave and Optical Technology Letters, 1995Co-Authors: Nam Quoc Ngo, X Dai, Le Nguyen BinhAbstract:We present an experimental implementation of the first-order monotonic Butterworth-type low-pass and high-pass Optical Filters, using a coherent all-zero fiber-optic filter (AZFOF), as a verification of our previously proposed theory [1]. The filter realization technique shows that the all-fiber Mach-Zehnder interferometer (AFMZI) belongs to a special class of the first-order monotonic Butterworth-type Optical filter. The phase-modulated AZFOF is shown to be a potential candidate as a tunable Optical blocking filter. © 1995 John Wiley & Sons. Inc.
-
novel realization of monotonic butterworth type lowpass highpass and bandpass Optical Filters using phase modulated fiber optic interferometers and ring resonators
Journal of Lightwave Technology, 1994Co-Authors: Nam Quoc Ngo, Le Nguyen BinhAbstract:A novel realization of monotonic Butterworth-type lowpass, highpass, and bandpass Optical Filters (from their electrical digital filter characteristics) by cascading the all-pole and all-zero resonators is presented. A graphical method for fast derivation of the transfer functions, quick inspection of the resonance effects, and important characteristics of any photonic circuits is described. It is shown that incorporation of the Optical amplifiers and Optical phase modulators into the delay lines of two basic Optical resonators, whose pole and zero can be adjusted independently of each other, provides great design flexibility which would otherwise not possible using conventional passive Optical resonators. Possible applications of these Optical Filters as Optical pulse equalizers and receiver shaping Filters in long-haul coherent lightwave transmission systems are discussed. Possible application of basic resonators comprising of Optical phase modulators as tunable Optical Filters for spectrum analyzers is also considered. >
Robert A Taylor - One of the best experts on this subject based on the ideXlab platform.
-
photovoltaic thermal system performance utilizing thin film and nanoparticle dispersion based Optical Filters
Journal of Renewable and Sustainable Energy, 2013Co-Authors: Todd Otanicar, Robert A Taylor, Chinmay TelangAbstract:Hybrid photovoltaic/thermal (PV/T) collectors would benefit from the use of fluid based Optical Filters as a means to separate the useful irradiance for the PV cell from those wavelengths which are more suited to heat generation. Nanoparticle based dispersions within a working fluid can be designed/tuned to serve as Optical Filters for this purpose. The advantage of this concept is that the thermal part of the system is separated, allowing the photovoltaic and thermal components to operate at significantly different temperatures. Additionally, by using a fluid filter, it is relatively easy to remove heat from the thermal side. This paper theoretically investigates the performance of nanoparticle-based and conventional thin film-based Optical fluid Filters within a concentrating hybrid PV/T system. General results are presented to demonstrate the impact to overall efficiency when a realistic (i.e., non-ideal) filter is used at a wide-range of operating conditions. The results demonstrate that nanoparticle based Filters have a slightly lower overall efficiency compared to the conventional thin film Filters due to their lower performance within the window of high transmittance to the PV cell. However, nanoparticle based Filters achieve up to 4% higher thermal efficiencies as a result of their significantly reduced filter thickness demonstrating their potential as a favorable compact and lower cost design.
-
photovoltaic thermal system performance utilizing thin film and nanoparticle dispersion based Optical Filters
Journal of Renewable and Sustainable Energy, 2013Co-Authors: Todd Otanicar, Robert A Taylor, Chinmay TelangAbstract:Hybrid photovoltaic/thermal (PV/T) collectors would benefit from the use of fluid based Optical Filters as a means to separate the useful irradiance for the PV cell from those wavelengths which are more suited to heat generation. Nanoparticle based dispersions within a working fluid can be designed/tuned to serve as Optical Filters for this purpose. The advantage of this concept is that the thermal part of the system is separated, allowing the photovoltaic and thermal components to operate at significantly different temperatures. Additionally, by using a fluid filter, it is relatively easy to remove heat from the thermal side. This paper theoretically investigates the performance of nanoparticle-based and conventional thin film-based Optical fluid Filters within a concentrating hybrid PV/T system. General results are presented to demonstrate the impact to overall efficiency when a realistic (i.e., non-ideal) filter is used at a wide-range of operating conditions. The results demonstrate that nanoparticle ...
-
feasibility of nanofluid based Optical Filters
Applied Optics, 2013Co-Authors: Robert A Taylor, Todd Otanicar, Yasitha Herukerrupu, Fabienne Bremond, Gary Rosengarten, Evatt R Hawkes, Xuchuan Jiang, Sylvain CoulombeAbstract:In this article we report recent modeling and design work indicating that mixtures of nanoparticles in liquids can be used as an alternative to conventional Optical Filters. The major motivation for creating liquid Optical Filters is that they can be pumped in and out of a system to meet transient needs in an application. To demonstrate the versatility of this new class of Filters, we present the design of nanofluids for use as long-pass, short-pass, and bandpass Optical Filters using a simple Monte Carlo optimization procedure. With relatively simple mixtures, we achieve Filters with <15% mean-squared deviation in transmittance from conventional Filters. We also discuss the current commercial feasibility of nanofluid-based Optical Filters by including an estimation of today's off-the-shelf cost of the materials. While the limited availability of quality commercial nanoparticles makes it hard to compete with conventional Filters, new synthesis methods and economies of scale could enable nanofluid-based Optical Filters in the near future. As such, this study lays the groundwork for creating a new class of selective Optical Filters for a wide range of applications, namely communications, electronics, Optical sensors, lighting, photography, medicine, and many more.
-
Nanofluid-based Optical filter optimization for PV/T systems
Light-Science & Applications, 2012Co-Authors: Robert A Taylor, Todd Otanicar, Gary RosengartenAbstract:Optical Filters are essential in a wide range of applications, including Optical communications, electronics, lighting, Optical sensors and photography. This article presents recent work which indicates that Optical Filters can be created from specialized nanoparticle suspensions. Specifically, this article describes a theoretical optimization process for designing nanofluid-based Filters for hybrid solar photovoltaic/thermal (PV/T) applications. This particular application is suitable because nanofluids can be utilized as both volumetric solar absorbers and flowing heat transfer mediums. The nanofluid Filters described in this work compare favorably with conventional Optical Filters for five photovoltaic (PV) cell alternatives: InGaP, CdTe, InGaAs, Si, and Ge. This study demonstrates that nanofluids make efficient, compact and potentially low-cost, spectrally selective Optical Filters.
Nam Quoc Ngo - One of the best experts on this subject based on the ideXlab platform.
-
realization of first order monotonic butterworth type low pass and high pass Optical Filters experimental verification
Microwave and Optical Technology Letters, 1995Co-Authors: Nam Quoc Ngo, X Dai, Le Nguyen BinhAbstract:We present an experimental implementation of the first-order monotonic Butterworth-type low-pass and high-pass Optical Filters, using a coherent all-zero fiber-optic filter (AZFOF), as a verification of our previously proposed theory [1]. The filter realization technique shows that the all-fiber Mach-Zehnder interferometer (AFMZI) belongs to a special class of the first-order monotonic Butterworth-type Optical filter. The phase-modulated AZFOF is shown to be a potential candidate as a tunable Optical blocking filter. © 1995 John Wiley & Sons. Inc.
-
novel realization of monotonic butterworth type lowpass highpass and bandpass Optical Filters using phase modulated fiber optic interferometers and ring resonators
Journal of Lightwave Technology, 1994Co-Authors: Nam Quoc Ngo, Le Nguyen BinhAbstract:A novel realization of monotonic Butterworth-type lowpass, highpass, and bandpass Optical Filters (from their electrical digital filter characteristics) by cascading the all-pole and all-zero resonators is presented. A graphical method for fast derivation of the transfer functions, quick inspection of the resonance effects, and important characteristics of any photonic circuits is described. It is shown that incorporation of the Optical amplifiers and Optical phase modulators into the delay lines of two basic Optical resonators, whose pole and zero can be adjusted independently of each other, provides great design flexibility which would otherwise not possible using conventional passive Optical resonators. Possible applications of these Optical Filters as Optical pulse equalizers and receiver shaping Filters in long-haul coherent lightwave transmission systems are discussed. Possible application of basic resonators comprising of Optical phase modulators as tunable Optical Filters for spectrum analyzers is also considered. >
-
butterworth novel realization of monotonic type lowpass highpass and bandpass Optical Filters using phase modulated fiber optic interferometers and ring resonators
1994Co-Authors: Nam Quoc NgoAbstract:A novel realization of monotonic Butterworth-type lowpass, highpass, and bandpass Optical Filters (from their elec- trical digital Filters characteristics) by cascading the all-pole and all-zero resonators is presented. A graphical method for fast deriving the transfer functions, quick inspection of the resonance effects and important characteristics of any photonic circuits is described. It is shown that incorporation of the Optical amplifiers and Optical phase modulators into the delay lines of two basic Optical resonators, whose pole and zero can be adjusted independently of each other, provides great design flexibility which would otherwise not possible by the conventional passive Optical resonators. Possible applications of these realized Optical Filters as Optical pulse equalizers and receiver shaping Filters in long-haul coherent lightwave transmission system are discussed. Possible application of the basic resonators comprising Optical phase modulators as tunable Optical Filters for spectrum analyzers is also considered.
Gary Rosengarten - One of the best experts on this subject based on the ideXlab platform.
-
feasibility of nanofluid based Optical Filters
Applied Optics, 2013Co-Authors: Robert A Taylor, Todd Otanicar, Yasitha Herukerrupu, Fabienne Bremond, Gary Rosengarten, Evatt R Hawkes, Xuchuan Jiang, Sylvain CoulombeAbstract:In this article we report recent modeling and design work indicating that mixtures of nanoparticles in liquids can be used as an alternative to conventional Optical Filters. The major motivation for creating liquid Optical Filters is that they can be pumped in and out of a system to meet transient needs in an application. To demonstrate the versatility of this new class of Filters, we present the design of nanofluids for use as long-pass, short-pass, and bandpass Optical Filters using a simple Monte Carlo optimization procedure. With relatively simple mixtures, we achieve Filters with <15% mean-squared deviation in transmittance from conventional Filters. We also discuss the current commercial feasibility of nanofluid-based Optical Filters by including an estimation of today's off-the-shelf cost of the materials. While the limited availability of quality commercial nanoparticles makes it hard to compete with conventional Filters, new synthesis methods and economies of scale could enable nanofluid-based Optical Filters in the near future. As such, this study lays the groundwork for creating a new class of selective Optical Filters for a wide range of applications, namely communications, electronics, Optical sensors, lighting, photography, medicine, and many more.
-
Nanofluid-based Optical filter optimization for PV/T systems
Light-Science & Applications, 2012Co-Authors: Robert A Taylor, Todd Otanicar, Gary RosengartenAbstract:Optical Filters are essential in a wide range of applications, including Optical communications, electronics, lighting, Optical sensors and photography. This article presents recent work which indicates that Optical Filters can be created from specialized nanoparticle suspensions. Specifically, this article describes a theoretical optimization process for designing nanofluid-based Filters for hybrid solar photovoltaic/thermal (PV/T) applications. This particular application is suitable because nanofluids can be utilized as both volumetric solar absorbers and flowing heat transfer mediums. The nanofluid Filters described in this work compare favorably with conventional Optical Filters for five photovoltaic (PV) cell alternatives: InGaP, CdTe, InGaAs, Si, and Ge. This study demonstrates that nanofluids make efficient, compact and potentially low-cost, spectrally selective Optical Filters.