Showing papers in "Journal of Lightwave Technology in 1996"
TL;DR: In this paper, a new class of long-period fiber gratings that can be used as in-fiber, low-loss, band-rejection filters is presented.
Abstract: We present a new class of long-period fiber gratings that can be used as in-fiber, low-loss, band-rejection filters. Photoinduced periodic structures written in the core of standard communication-grade fibers couple light from the fundamental guided mode to forward propagating cladding modes and act as spectrally selective loss elements with insertion losses act as backreflections <-80 dB, polarization-mode-dispersions <0.01 ps and polarization-dependent-losses <0.02 dB.
1,696Â citations
TL;DR: In this paper, the authors present a review of various wavelength conversion techniques, discusses the advantages and shortcomings of each technique, and addresses their implications for transparent WDM networks, and discuss their potential advantages over the optoelectronic counterpart.
Abstract: WDM networks make a very effective utilization of the fiber bandwidth and offer flexible interconnections based on wavelength routing. In high capacity, dynamic WDM networks, blocking due to wavelength contention can he reduced by wavelength conversion. Wavelength conversion addresses a number of key issues in WDM networks including transparency, interoperability, and network capacity. Strictly transparent networks offer seamless interconnections with full reconfigurability and interoperability. Wavelength conversion may be the first obstacle in realizing a transparent WDM network. Among numerous wavelength conversion techniques reported to date, only a few techniques offer strict transparency. Optoelectronic conversion (O/E-E/O) techniques achieve limited transparency, yet their mature technologies allow deployment in the near future. The majority of all-optical wavelength conversion techniques also offer limited transparency but they have a potential advantage over the optoelectronic counterpart in realizing lower packaging costs and crosstalk when multiple wavelength array configurations are considered. Wavelength conversion by difference-frequency generation offers a full range of transparency while adding no excess noise to the signal. Recent experiments showed promising results including a spectral inversion and a 90 nm conversion bandwidth. This paper reviews various wavelength conversion techniques, discusses the advantages and shortcomings of each technique, and addresses their implications for transparent networks.
928Â citations
TL;DR: In this article, the influence of saturation filtering on the bandwidth of the converters is explained and conditions for conversion at 20 Gb/s or more are identified for monolithic integrated interferometric wavelength converters.
Abstract: Following a brief introduction to the applications for wavelength conversion and the different available conversion techniques, the paper gives an in depth analysis of cross gain and cross phase wavelength conversion in semiconductor optical amplifiers. The influence of saturation filtering on the bandwidth of the converters is explained and conditions for conversion at 20 Gb/s or more are identified. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths. This can be overcome using cross phase modulation in semiconductor optical amplifiers that are integrated into interferometric structures. The first results for monolithic integrated interferometric wavelength converters are reviewed, and the quality of the converted signals is demonstrated by transmission of 10 Gb/s converted signals over 60 km of nondispersion shifted single mode fiber.
855Â citations
TL;DR: In this paper, it was shown that both the length scales for polarization mode dispersion and polarization decorrelation measured with respect to the local axes of birefringence are equal to the fiber autocorrelation length and that the coupled nonlinear Schrodinger equation which describes wave evolution over long length along a communication fiber can be reduced to the Manakov equation.
Abstract: Polarization mode dispersion and the polarization decorrelation and diffusion lengths are calculated in fibers with randomly varying birefringence. Two different physical models in which the birefringence orientation varies arbitrarily are studied and are shown to yield nearly identical results. These models are appropriate for communication fibers. We show that both the length scales for polarization mode dispersion and polarization decorrelation measured with respect to the local axes of birefringence are equal to the fiber autocorrelation length. We also show that the coupled nonlinear Schrodinger equation which describes wave evolution over long length along a communication fiber can be reduced to the Manakov equation. The appropriate averaging length for the linear polarization mode dispersion is just the fiber autocorrelation length but the appropriate averaging length for the nonlinear terms is the diffusion length in the azimuthal direction along the Poincare sphere which can be different, The implications for the nonlinear evolution are discussed.
447Â citations
TL;DR: In this article, the impact of crosstalk in an arrayed-waveguide N/spl times/N wavelength multiplexer is investigated precisely in relation to its application to wavelength-routing N /spl times /N all optical networks.
Abstract: The impact of crosstalk in an arrayed-waveguide N/spl times/N wavelength multiplexer is investigated precisely in relation to its application to wavelength-routing N/spl times/N all optical networks. In such systems multiple crosstalk light which has the same wavelength as the signal results in signal-crosstalk beat noise. We confirm that the noise is Gaussian and obtain the relation between crosstalk and power penalty. It is shown that the crosstalk must be less than -38 dB for a 16/spl times/16 system to keep the power penalty below 1 dB at a bit error rate of 10/sup -9/.
283Â citations
TL;DR: In this article, a new method was proposed to compensate exactly for both chromatic dispersion and self-phase modulation in a transmission fiber, where the light intensity changes due to fiber loss and amplifier gain.
Abstract: We propose a new method to compensate exactly for both chromatic dispersion and self-phase modulation in a transmission fiber, where the light intensity changes due to fiber loss and amplifier gain. This method utilizes optical phase conjugation (OPC). The pulse shape is precompensated before OPC by transmission through a fiber with large dispersion. A computer simulation demonstrates effective compensation for waveform distortion in a 40 Gb/s NRZ intensity-modulated light transmission.
258Â citations
TL;DR: In this article, the authors present an overview of the multi-wavelength optical networking (MONET) program and summarize its vision, including network elements, networking demonstration plans, network control and management, and architecture and economics.
Abstract: This paper presents an overview of the multiwavelength optical networking (MONET) program and summarizes its vision. The program objective is to advance, demonstrate, and integrate network architecture and economics, advanced multiwavelength technology, and network management and control to achieve high capacity, reconfigurable, high performance, reliable multiwavelength optical networks, with scalability to national scale, for both commercial and specialized government applications. The paper describes the major research thrusts of the program including network elements, networking demonstration plans, network control and management, and architecture and economics.
254Â citations
TL;DR: In this paper, the nonlinearities in p-i-n photodetectors have been measured and numerically modeled, and it was shown that the p-region absorption and carrier-dependent carrier velocities associated with a perturbed electric field (due to space charge and loading effects) are dominant photoderiver nonlinear behavior.
Abstract: The nonlinearities in p-i-n photodetectors have been measured and numerically modeled. Harmonic distortion measurements were made with two single-frequency offset-phased-locked Nd:YAG lasers which provide a source dynamic range greater than 130 dB and a 1 MHz-50 GHz frequency range. Carrier transport is analytically described by three coupled nonlinear differential equations, Poisson's equation and the hole and electron continuity equations. These equations are numerically solved to investigate and isolate the various nonlinear mechanisms. The numerical solution incorporates diffusion since our treatment includes carrier generation in the highly doped p-region of the device. This p-region absorption and carrier-dependent carrier velocities associated with a perturbed electric field (due to space-charge and loading effects) are shown to dominate photodetector nonlinear behavior. The numerical model was extended to predict that maximum photodetector currents of 100 mA should be possible in 20 GHz bandwidth devices before a sharp increase in nonlinear output occurs. In addition, second harmonic distortion improvements of 40-60 dB may be possible if photodetectors can be fabricated with strictly-depleted absorbing regions.
236Â citations
TL;DR: In this paper, the interaction of all-fiber acousto-optic devices based on the null fused taper coupler has been extensively analyzed under a set of approximations that are valid in most cases.
Abstract: All-fiber acousto-optic devices based on the null fused taper coupler have been successfully demonstrated as frequency shifters, variable splitters, switches and tunable filters. In this paper, the interaction upon which these devices are based has been extensively analyzed under a set of approximations that are valid in most cases. Simple analytical expressions for the important properties are derived, which provide a set of design rules for such devices.
202Â citations
TL;DR: Initial investigations indicate that the system can be so configured to allow high level of protection against determined attack, with this being especially true for an asymmetric system.
Abstract: Analysis of hybrid wavelength hopping/time spreading systems and their classification into symmetric and asymmetric systems (undercolored and overcolored asymmetric systems) is given. The characteristics of a hybrid system using extended quadratic congruence sequences for spreading and prime sequences and their cyclic shifts for hopping are examined. It is shown that the sequences exhibit excellent cross-correlation properties even in the case of a general asymmetric overcolored system. Analysis of the security properties of hybrid systems is presented both from the viewpoint of exhaustive search and from the viewpoint of chosen attack. Initial investigations indicate that the system can be so configured to allow high level of protection against determined attack, with this being especially true for an asymmetric system. Because of the massive number of users the system can support, the proposed scheme is suitable for large optical LAN's with increased security demands.
183Â citations
TL;DR: In this article, the SBS threshold of a fiber with Brillouin frequency shift distribution along its length is investigated theoretically and experimentally, and a simple equation for estimating the sBS threshold from the effective gain coefficient, which is calculated by using the frequency distribution along the length of the fiber.
Abstract: The SBS threshold of a fiber with Brillouin frequency shift distribution along its length is investigated theoretically and experimentally. We obtain a simple equation for estimating the SBS threshold from the effective gain coefficient, which is calculated by using the Brillouin frequency distribution along its length. The dopant concentration dependence of the Brillouin frequency shift are measured for fibers with an F and GeO/sub 2/ codoped silica core. The evaluated frequency shift per unit of dopant concentration is 277 MHz/wt% and 45 MHz/wt% for F and GeO/sub 2/, respectively, at 1.55 /spl mu/m. The SBS threshold of a fiber with a nonuniform Brillouin frequency shift distribution prepared by the VAD method is investigated experimentally. The fiber exhibits 7 dB improvement in its SBS threshold. This value is in good agreement with one estimated by calculating the effective gain coefficient. This simple equation will be useful for estimating the SBS threshold of various fibers.
TL;DR: In this paper, the authors describe techniques used to transmit many WDM channels over transoceanic distances using the nonreturn-to-zero format and other nonsoliton methods.
Abstract: Wavelength division multiplexing shows great promise for the next generation of long-haul undersea cable transmission systems. WDM techniques will allow for greater transmission capacity and network flexibility compared to the present single-channel optical amplifier systems. The transmission of many WDM channels over transoceanic distances can be limited by a variety of phenomena, including the finite bandwidth of the erbium-doped fiber amplifier repeaters, the nonlinear interactions between channels, and the noise accumulation along the chain of amplifiers. Significant progress has been made over the past few years in understanding the nature of these impairments for long-distance transmission. This paper describes techniques used to transmit many WDM channels over transoceanic distances using the nonreturn-to-zero format and other nonsoliton methods. Data is presented for several WDM experiments including the transmission of 100 Gb/s (20 channels of 5 Gb/s) over 9100 km.
TL;DR: In this paper, a maskless laser-based microfabrication technique for the photochemical delineation of raised-rib single-mode waveguiding devices in polymers is described.
Abstract: Organic polymeric materials offer a versatile medium for the creation of low-cost large-area optical guided-wave structures. In this work, we report on the use of a novel maskless laser-based microfabrication technique for the photochemical delineation of raised-rib single-mode waveguiding devices in polymers. This technology relies on accurate control of small refractive index differences (which is achieved by using intermiscible acrylate monomers), use of high-contrast photochemical response, as well as precise control of laser writing parameters. The devices reported here have cross-sectional dimensions and numerical apertures that match single-mode glass optical fibers. They exhibit very low losses of 0.03 dB/cm at 840 nm and exceptional thermal stability. We present the operational characteristics of bends, Y-branches, and directional couplers fabricated using this technology and compare these characteristics with those predicted from theory.
TL;DR: In this paper, the authors explored the optical path cross-connect (OPXC) node architectures that are essential components of the OPXC, which handles optical paths, is constructed with an optical switching network.
Abstract: This paper explores the optical path cross-connect (OPXC) node architectures that are essential components of the optical path network. Optical path technologies will play a key role in the development of the platform on which the future bandwidth abundant B-ISDN should be created. This paper highlights the wavelength path (WP) and the virtual wavelength path (VWP) technologies, both of which can greatly enhance the path layer capability and the efficiency of network failure restoration. The OPXC, which handles optical paths, is constructed with an optical switching network. Various WDM-based switching networks, which are aimed at LAN applications, have been reported. On the other hand, few WDM-based switching networks for OPXC systems, which are applicable to the nationwide transport network, have been proposed. In this paper, we elucidate the functional conditions required to construct OPXC nodes for WP and VWP global networks. Next, we assess switching network architectures for their applicability to the transport network. It is shown that the OPXC architecture based on DC-switches (delivery and coupling switches) is superior to the other OPXC architectures in terms of optical losses, modularity, and upgradability. Finally, detailed evaluations of the DC-switch-based OPXC node are presented that confirm its feasibility.
TL;DR: In this paper, the authors theoretically and experimentally investigated the cross-phase modulation (XPM) effect in optical fiber links with multiple optical amplifiers and dispersion compensators, and they showed that the XPM effect can be modeled as a phase modulator with inputs from the intensity of copropagating waves.
Abstract: We have theoretically and experimentally investigated the cross-phase modulation (XPM) effect in optical fiber links with multiple optical amplifiers and dispersion compensators. Our theory suggests that the XPM effect can be modeled as a phase modulator with inputs from the intensity of copropagating waves. The frequency response of the phase modulator corresponding to each copropagating wave depends on fiber dispersion, wavelength separation, and fiber length. The total XPM-induced phase shift is the integral of the phase shift contributions from all frequency components of copropagating waves. In nondispersive fibers, XPM is frequency-independent; in dispersive fibers, XPM's frequency response is approximately inversely proportional to the product of frequency, fiber dispersion, and wavelength separation. In an N-segment amplified link, the frequency response of XPM is increased N-fold, but only in very narrow frequency bands. In most other frequency bands, the amount of increase is limited and almost independent of N. However, in an N-segment amplified link with dispersion compensators, the frequency response of XPM is increased N-fold at all frequencies if the dispersion is compensated for within each fiber segment. Thus, the XPM-induced phase shift is smaller in systems employing lumped dispersion compensation than in systems employing distributed dispersion compensation.
TL;DR: In this article, the authors derived analytical formulas for the enhancement of spontaneous emission along the optical axis of the cavity and established the design rules for high-efficiency operation of RCLEDs.
Abstract: Resonant-cavity light-emitting diodes (RCLED) are novel, high-efficiency light-emitting diodes which employ optical microcavities. These diodes have higher intensities and higher spectral purity as compared to conventional LEDs. Analytical formulas are derived for the enhancement of the spontaneous emission along the optical axis of the cavity. The design rules for high-efficiency operation of RCLEDs are established. The temperature dependence of the emission intensity is analyzed in the range 20-80/spl deg/ and it is described by an exponential dependence with a characteristic temperature of 112 K. The modulation characteristics of RCLEDs exhibit 3 dB frequencies of 580 MHz. Eye diagrams at transmission rates of 622 Mb/s are wide open indicating the suitability of RCLEDs for high-speed data transmission.
TL;DR: In this article, the feasibility and limitations of optical data storage in a fiber loop optical buffer are studied theoretically and experimentally, a model of a fiber-loop buffer, incorporating semiconductor laser amplifiers (SLA) as switching gates, is described.
Abstract: Fiber loop optical buffers enable data storage for discrete time intervals and therefore appear suitable for applications in optical asynchronous transfer mode (OATM)-based networks where data are transmitted in cells of fixed length. In this paper, the feasibility and the limitations of optical data storage in a fiber loop optical buffer are studied theoretically and experimentally, A model of a fiber loop buffer, incorporating semiconductor laser amplifiers (SLA) as switching gates, is described. The two major interfering quantities are cross talk and amplified spontaneous emission of the SLA gates. To limit the impact of cross talk on the signal quality, an on/off ratio of the SLA gates of at least 30 dB is required. The paper describes the optimum operation conditions, which enable data storage for more than 100 circulations even for data rates in the range from 10 to 160 Gb/s.
TL;DR: In this paper, the semiconductor laser rate equations are rewritten using a new set of parameters which can all be found from steady state and small signal measurements on the laser and procedures for finding these parameters are described.
Abstract: The semiconductor laser rate equations are rewritten using a new set of parameters which can all be found from steady state and small signal measurements on the laser. Procedures for finding these parameters are described. Parameters have been measured on three 1550 mm lasers from different manufacturers. Comparison between large signal measurements and simulations using the measured parameters shows in general good agreement for modulation currents sufficiently above threshold.
TL;DR: In this paper, a robust, tunable single-longitudinal-mode compound-ring Er/sup 3+/-doped fiber laser is presented, which can provide up to 20 mW output power over much of its 1525 to 1570 nm wavelength tuning range.
Abstract: In this paper we report the fabrication of a robust, tunable single-longitudinal-mode compound-ring Er/sup 3+/-doped fiber laser. The laser is fundamentally structured on an all-fiber compound-ring resonator in which a dual-coupler fiber ring is inserted into the main cavity. When combined in tandem with a mode-restricting intracavity tunable bandpass filter, the compound-ring resonator ensures single-longitudinal-mode laser oscillation. The laser can provide up to 20 mW output power over much of its 1525 to 1570 nm wavelength tuning range. The short-term linewidth of the laser output measured is less than 5 kHz. The laser frequency is actively stabilized for a long time by exploiting the inherent filter nature of the compound-ring resonator. The reduction of an associated frequency modulation is also discussed in detail.
TL;DR: The code-division multiple-access (CDMA) technique is applied for multimedia transmission in fiber-optic networks and it is shown that for successful operation, new families of optical orthogonal codes (OOCs) are needed which will have not only good correlation properties within one code family, but also between families of different code lengths.
Abstract: In this paper, we address the problem of multimedia transmission in fiber-optic networks. We apply the code-division multiple-access (CDMA) technique for such a network. The necessary conditions for successful operation of the network are given. It is shown that for successful operation, new families of optical orthogonal codes (OOCs) are needed which will have not only good correlation properties within one code family, but also between families of different code lengths. Some possible constructions of multimedia OOCs and the corresponding basic structure of the receiver for the multimedia network are given. Specific examples of OOCs for the case of users with two different data rates are given, and the probability of error (using the Gaussian approximation) as a function of the number of low and high rate users is calculated.
TL;DR: In this paper, the authors proposed a move-to-vacant wavelength-retuning (MTV WR) scheme to reduce the disruption period in a wide-area all-optical wavelength division multiplexed (WDM) network with random circuit arrivals and departures.
Abstract: This paper considers rerouting and minimization of incurred disruption due to rerouting in a wide-area all-optical wavelength division multiplexed (WDM) network with random circuit arrivals and departures. One limitation of such a network is the wavelength continuity constraint imposed by the all-optical cross-connect switches which do not allow a circuit to be placed on a nonwavelength-continuous route. Wavelength rerouting is proposed to rearrange certain existing circuits to create a wavelength-continuous route in order to accommodate a new circuit. To reduce the disruption period, move-to-vacant wavelength-retuning (MTV WR) is used as the basic operation of circuit migration, in which a circuit is moved to a vacant wavelength on the same path, and parallel MTV WR rerouting is used to reroute multiple circuits. An optimal algorithm is developed to minimize the weighted number of rerouted circuits with parallel MTV WR rerouting. In our test network, wavelength rerouting can effectively alleviate the wavelength continuity constraint by reducing call blocking probability an average of 30 % while reducing the number of rerouted circuits and the disruption period,.
TL;DR: In this article, the performance of a fiber grating interrogation system using an acousto-optic tunable filter (AOTF) was analyzed for both transmissive and reflective interrogation of FBGs.
Abstract: The performance of a fiber grating interrogation system using an acousto-optic tunable filter (AOTF) is analyzed. An equivalent linear circuit is presented to describe the system, which tracks the wavelength of a fiber Bragg grating (FBG) sensor in a FBG sensor array. From the model, the tracking resolution of a shot-noise-limited system has been determined for both transmissive and reflective interrogation of FBGs. An optimum ratio between the bandwidths of the FBG and the AOTF has been derived. Experimental results of a tracking system are presented to validate the theoretical predictions. The theory should also be suitable for interrogation systems using other forms of tunable bandpass filters for tracking the FBG wavelength.
TL;DR: In this paper, the input and output waveguides were integrated with a multiple-quantum-well (MQW) electro-absorption (EA) optical modulator to achieve ultra-high-speed modulation while keeping the total device length long enough for easy fabrication and packaging.
Abstract: Integrating the input and output waveguides with a multiple-quantum-well (MQW) electro-absorption (EA) optical modulator is shown to achieve ultra-high-speed modulation while keeping the total device length long enough for easy fabrication and packaging. Testing with fabricated modulators showed that a shorter modulation region results in a larger modulation bandwidth. The additional loss due to the waveguide integration was less than 1 dB. An optimized modulator showed a large modulation bandwidth of 50 GHz, a low driving voltage of less than 3 V, and a low insertion loss of 8 dB. A prototype module of this modulator had a bandwidth of greater than 40 GHz. Optimizing the MQW structure makes the modulator insensitive to polarization. These results demonstrate that MQW-EA modulators with integrated waveguides are advantageous in terms of fabrication, packaging, and ultra-high-speed modulation.
TL;DR: The architecture of the testbed and its nodes is presented together with a description of the key component technologies and network control and management is discussed along with applications and services.
Abstract: This paper describes the multiwavelength reconfigurable all-optical network testbed designed and constructed as a part of the optical networks technology consortium (ONTC) phase I program with a group of working members consisting of Bellcore, Columbia University, Hughes Research Laboratories, Northern Telecom, Rockwell Science Center, Case Western Reserve University, United Technology Research Center, Uniphase Telecommunications Product, and Lawrence Livermore National Laboratories. The architecture of the testbed and its nodes is presented together with a description of the key component technologies. Network control and management is discussed along with applications and services.
TL;DR: In this article, different optical cross-connect architectures, based either on space division or wavelength division switching, are analyzed and a comparative investigation is accomplished considering three issues of primary importance: crossconnect modularity, complexity, and transmission performance.
Abstract: The introduction of optical technology in the path layer of the transport network is expected to allow scalable and modular networks to be realized. In this paper, different optical cross-connect architectures, based either on space division or wavelength division switching, are analyzed. A comparative investigation is accomplished considering three issues of primary importance: cross-connect modularity, complexity, and transmission performance. In particular, the transmission performance of a generic path through the network is evaluated by upgrading a previously published analytical model, so to more accurately take into account the in-band crosstalk arising in the cross-connect.
TL;DR: Simulation results show that the throughput limitations and the fairness problems inherent in the network topology can be overcome with relatively simple protocols.
Abstract: The paper illustrates novel proposals for medium access control protocols in all-optical packet networks based on WDM multichannel ring topologies where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter. Such networks provide separate slotted channels for disjoint subsets of destination nodes. Three access protocols based on local status information are described. A channel inspection capability is assumed to be available for the implementation of the access protocols. Global fairness control algorithms derived from those adopted in the Metaring high-speed metropolitan area network are also proposed. Access delays and throughputs are taken as performance Indices for a simulation-based comparison of the proposed protocols, in the case of a 16-node multiring with either balanced or unbalanced traffic. Simulation results show that the throughput limitations and the fairness problems inherent in the network topology can be overcome with relatively simple protocols.
TL;DR: In this article, the authors evaluate the tradeoff in optical slice linewidth between signal-to-excess optical noise ratio and dispersion penalty in spectrum-sliced WDM systems and determine the channel slicewidth that minimizes transmission penalty.
Abstract: We simulate transmission of a spectrum-sliced WDM channel operating at high bit rates (e.g., 622 to 2488 Mb/s). We calculate the bit error rate using the non-Gaussian statistics of thermal light sources that are commonly used in spectrum slicing and account for the effects of fiber dispersion. We evaluate the tradeoff in optical slice linewidth between signal-to-excess optical noise ratio and dispersion penalty in spectrum-sliced WDM systems, and determine the channel slicewidth that minimizes transmission penalty for a given link length and bit rate. We compare our simulations against the measured performance of a 1244 Mb/s channel over 20 km of fiber. The results in this paper provide useful information for the design of spectrum-sliced WDM networks.
ETSI1
TL;DR: In this paper, the equalization performance of various apodization functions in linearly chirped fiber gratings is investigated and compared, with a view of determining an optimum profile for the design and fabrication of chromatic dispersion compensators.
Abstract: We investigate and compare the equalization performance of various apodization functions in linearly chirped fiber gratings, with a view of determining an optimum profile for the design and fabrication of chromatic dispersion compensators A discussion concerning the relation of these apodization functions with the group delay characteristic of the equalizer is presented yielding important results connected with the grating design The analysis has been extended to consider nonideal effects such as nonconstant averaged index and a realistic optical source
TL;DR: In this paper, a dual-depletion region p-i-n photodetector is proposed, which has a parasitic capacitance and transit time that can be controlled semi-independently.
Abstract: The design of a new kind of photodetector, the dual-depletion region p-i-n photodetector, is presented. This vertical detector has a parasitic capacitance and transit time that can be controlled semi-independently. This eases the classical tradeoff between these two speed limiting factors, allowing the design of large, fast detectors. A theoretical analysis of the transit time effect and the capacitance effect is made. This analysis is then used to compute optimum design parameters.
TL;DR: The transmission-line representation can serve as a template for computational algorithms that systematically evaluate dispersion properties, radiation effects, wave coupling and other characteristics that are not readily obtained by other methods.
Abstract: Solutions to problems involving the scattering and guiding of waves by multilayered grating configurations can be phrased in rigorous modal terms. We show that such a modal solution can be represented by electrical transmission-line networks, which are generalized forms of simpler conventional circuits. This approach brings considerable physical insight into the grating diffraction process and facilitates the derivation of the fields everywhere. In particular, the transmission-line representation can serve as a template for computational algorithms that systematically evaluate dispersion properties, radiation effects, wave coupling and other characteristics that are not readily obtained by other methods. Examples illustrating the application of the present approach are given for waves guided by grating configurations encountered in optoelectronic devices.