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Lightwave Technology, Journal of

Issue 1 • Date Jan 2003

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Displaying Results 1 - 25 of 39
  • Multiwavelength erbium-doped fiber lasers with active overlapping linear cavities

    Publication Year: 2003 , Page(s): 160 - 169
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (936 KB) |  | HTML iconHTML  

    Multiwavelength oscillations in erbium-doped fiber (EDF) lasers with active overlapping linear cavities are investigated in detail. The laser can be designed to produce multiwavelength oscillations in the C-band and in the L-band. With a C-band three-wavelength laser, experiments show that the output powers of the lasing lines increase linearly or piecewise linearly with pump input. Any one lasing wavelength can be tuned over several nanometers depending on the gain tilt in the vicinity of the lasing wavelength while multiwavelength oscillation is still being maintained. The output power of any specific lasing line can be adjusted by suitably designing the EDF sections. This property also allows the laser to operate in multiwavelength switching mode. The laser exhibits a novel multiwavelength optical bistable behavior in the L-band. With an L-band dual-wavelength laser, the bistable input-output hysteresis behaviors of the two L-band wavelengths evolve in antiphase with respect to each other. The width of the bistable region has been increased to several tens of mW. It can be controlled and adjusted by the cavity loss and the EDF length. It is found that simultaneous L-band dual-wavelength oscillations can be obtained when part of the EDF, which functions as a saturable absorber, has been bleached. Moreover, simultaneous multiwavelength oscillations in both C-band and L-band have also been successfully demonstrated with the laser. View full abstract»

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  • Fabrication and characteristics of GaP-AlGaP tapered waveguide semiconductor Raman amplifiers

    Publication Year: 2003 , Page(s): 170 - 175
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (578 KB) |  | HTML iconHTML  

    We have fabricated GaP-AlGaP tapered waveguide semiconductor Raman amplifiers, and analyzed the effect of tapering in pulse-pumped high-gain operation. The finesse measurement and 80-ps pulse pumped Raman amplification experiment were performed. Although the tapering has caused additional optical loss, the highest gain of 23 dB has been obtained for a tapered waveguide with input facet of 6.0 μm2 and back facet of 2.9 μm2 at averaged input power of 170 mW (peak power 26 W). It is shown that the optical loss of the pump light is more severe than the linear optical loss of the signal light when the gain is higher than 20 dB. View full abstract»

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  • Polarization crosstalk in high index contrast planar silica waveguides with slanted sidewalls

    Publication Year: 2003 , Page(s): 54 - 60
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (496 KB) |  | HTML iconHTML  

    Numerically simulated results, by using rigorous full vectorial approaches, indicate the possibility of significant polarization crosstalk in a high index contrast planar silica waveguide, particularly when the sidewalls are not exactly vertical. View full abstract»

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  • Variable numerical-aperture temporal-coherence measurement of resonant-cavity LEDs

    Publication Year: 2003 , Page(s): 149 - 154
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (390 KB) |  | HTML iconHTML  

    The first interferometric measurements of temporal-coherence length variation with numerical aperture (NA) are described for 650 nm, resonant-cavity light-emitting diodes (LEDs) agreeing with spectrally derived results. The interferometrically measured coherence length (22 μm to 32 μm) reduced by 37% for a 0.42 increase in NA. For a larger range of NA (0-1), this would give coherence lengths (10 μm-40 μm) lying in the gap between that of conventional LEDs (∼5 μm) and superluminescent diodes (∼60 μm). View full abstract»

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  • Accurate noise characterization of wavelength converters based on XGM in SOAs

    Publication Year: 2003 , Page(s): 182 - 197
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (923 KB) |  | HTML iconHTML  

    Wavelength conversion (WCR) has recently emerged as an important technique that can be used to manage the spectacular increase in traffic in dense wavelength division multiplexing (DWDM) networks. WCR is extremely useful to solve contention, reduce wavelength blocking and a wide range of WCR methods have been reported. The optimum placement of these devices within a network remains an unexplored area and accurate models to measure the performance of the system are becoming vital. Therefore, this paper presents an original noise characterization of a class of WCRs based on cross-gain modulation (XGM) in semiconductor optical amplifiers (SOAs) when the components from spontaneous emission of the SOAs at the receiver are dominant over thermal and shot noise terms. A new and simple expression for the error probability (Pe) is presented offering considerable additional accuracy in sensitivity assessment compared with the Gaussian approach when ASE noise is dominant. Simulation comparisons are presented in different scenarios for a standard system working at 2.5 Gb/s in a metropolitan area network taking into account the key parameters when such systems are designed. View full abstract»

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  • Design of grating-assisted codirectional couplers with discrete inverse-scattering algorithms

    Publication Year: 2003 , Page(s): 254 - 263
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (539 KB) |  | HTML iconHTML  

    We present a flexible and accurate approach for the design of grating-assisted codirectional couplers. The design method is based on a discrete coupling model. The two spectral responses of the coupler are chosen according to certain physical constraints. We prove necessary and sufficient conditions for realizability and demonstrate how they can be applied for determining an optimal coupler response. The ambiguity when designing a coupler with a specified cross-coupling response is also discussed in detail. Once the realizable responses have been found, they can be applied as input to a layer-peeling inverse-scattering method which computes the required coupler structure. The layer-peeling algorithm is implemented in the time domain for increased efficiency and clarity. Since the algorithm is tailored to the special case of codirectional coupling, divergence problems for strong coupling is avoided. Numerical design examples are shown in order to illustrate the performance of the method. Various realizations of square passband filters with high power transfer and a long-period fiber grating filter for EDFA gain flattening within the entire C-band have been designed. View full abstract»

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  • Tree-shared multicast in optical burst-switched WDM networks

    Publication Year: 2003 , Page(s): 13 - 24
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (566 KB) |  | HTML iconHTML  

    In this paper, we propose a new multicast scheme called tree-shared multicasting (TS-MCAST) in optical burst-switched wavelength-division-multiplexing networks, taking into consideration overheads due to control packets and guard bands (GBs) associated with data bursts. In TS-MCAST, multicast traffic belonging to multiple multicast sessions from the same source-edge node to possibly different destination-edge nodes can be multiplexed together in a data burst, which is delivered via a shared multicast tree. To support TS-MCAST, we propose three tree-sharing strategies based on equal coverage, super coverage, and overlapping coverage, and present a simple shared multicast tree-construction algorithm. For performance comparison, we consider two other multicast schemes: separate multicasting (S-MCAST) and multiple unicasting (M-UCAST). We show that TS-MCAST outperforms S-MCAST and M-UCAST in terms of bandwidth consumed and processing load (i.e., number of control packets) incurred for a given amount of multicast traffic under the same unicast traffic load with static multicast sessions and membership. View full abstract»

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  • High-output-power polarization-insensitive semiconductor optical amplifier

    Publication Year: 2003 , Page(s): 176 - 181
    Cited by:  Papers (35)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (386 KB) |  | HTML iconHTML  

    A high-output-power 1550 nm polarization-insensitive semiconductor optical amplifier (SOA) was developed for use as a compact in-line optical amplifier. A very thin tensile-strained bulk structure was used for the active layer and active width-tapered spot-size converters (SSCs) were integrated on both input and output sides. The SOA module exhibited a high saturation output power of +17 dBm together with a low noise figure of 7 dB, large gain of 19 dB, and low polarization sensitivity of 0.2 dB for optical signals of 1550 nm wavelength. For the amplification of optical signals modulated at 10 Gb/s in the nonreturn-to-zero (NRZ) format, a good eye pattern without waveform distortion due to the pattern effect was obtained at an average output power of up to +12 dBm. Additionally, good amplification characteristics were demonstrated for the signal wavelength range corresponding to the C-band. View full abstract»

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  • Optical packet switching and buffering by using all-optical signal processing methods

    Publication Year: 2003 , Page(s): 2 - 12
    Cited by:  Papers (109)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (706 KB) |  | HTML iconHTML  

    We present a 1 × 2 all-optical packet switch. All the processing of the header information is carried out in the optical domain. The optical headers are recognized by employing the two-pulse correlation principle in a semiconductor laser amplifier in loop optical mirror (SLALOM) configuration. The processed header information is stored in an optical flip-flop memory that is based on a symmetric configuration of two coupled lasers. The optical flip-flop memory drives a wavelength routing switch that is based on cross-gain modulation in a semiconductor optical amplifier. We also present an alternative optical packet routing concept that can be used for all-optical buffering of data packets. In this case, an optical threshold function that is based on a asymmetric configuration of two coupled lasers is used to drive a wavelength routing switch. Experimental results are presented for both the 1 × 2 optical packet switch and the optical buffer switch. View full abstract»

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  • Design of double-coated optical fibers to minimize long-term tensile-force-induced delamination of polymeric coatings from glass fibers

    Publication Year: 2003 , Page(s): 106 - 110
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (531 KB) |  | HTML iconHTML  

    The design of double-coated optical fibers to minimize long-term tensile-force-induced delamination of polymeric coatings from glass fibers is investigated using viscoelastic theory. To prevent the delamination of polymeric coatings from glass fibers, the tensile-force-induced interfacial shear stress between the glass fiber and primary coating should be always smaller than its interfacial shear strength in the long term. The tensile-force-induced interfacial shear stress can be minimized by properly selecting physical properties of polymeric coatings and their thicknesses. The method for the minimization of the long-term tensile-force-induced delamination of polymeric coatings from glass fibers in double-coated optical fibers is proposed. View full abstract»

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  • Transmission characteristics of long-period fiber gratings having arbitrary azimuthal/radial refractive index variations

    Publication Year: 2003 , Page(s): 218 - 227
    Cited by:  Papers (18)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (867 KB) |  | HTML iconHTML  

    A numerical method is presented for determining the transmittance of long-period (LP) fiber-gratings having arbitrary azimuthal/radial refractive index variations. The method uses coupled-mode theory and includes both the sine and cosine character of the LP modes. The model treats interactions between the fundamental LP01 mode and high-azimuthal-order cladding modes. The method utilizes the transfer matrix method to model cylindrical layers both in the core and the cladding regions. View full abstract»

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  • Comparison of FWM- and XPM-induced crosstalk using the Volterra series transfer function method

    Publication Year: 2003 , Page(s): 40 - 53
    Cited by:  Papers (34)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (909 KB)  

    New analytical tools to calculate the variance due to cross-phase modulation (XPM) and four-wave mixing (FWM) induced intensity distortion are derived based on the Volterra series transfer function method. The analysis for both the XPM and FWM effects is based on the same system configuration with a continuous-wave (CW) probe channel plus modulated pump channels, which makes possible a fair comparison between the two nonlinear effects. Effective ways to reduce the XPM- and FWM-induced intensity distortion are given. The new results on the variance of the nonlinearity-induced intensity fluctuation also make it possible to study both synchronous wavelength-division multiplexing (WDM) systems with fixed channel delays and asynchronous WDM systems with random channel delays. The new analytical results provide accurate and efficient ways for system parameter optimization to reduce these two nonlinear effects. View full abstract»

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  • Optimization of the split-step Fourier method in modeling optical-fiber communications systems

    Publication Year: 2003 , Page(s): 61 - 68
    Cited by:  Papers (130)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB) |  | HTML iconHTML  

    We studied the efficiency of different implementations of the split-step Fourier method for solving the nonlinear Schrödinger equation that employ different step-size selection criteria. We compared the performance of the different implementations for a variety of pulse formats and systems, including higher order solitons, collisions of soliton pulses, a single-channel periodically stationary dispersion-managed soliton system, and chirped return to zero systems with single and multiple channels. We introduce a globally third-order accurate split-step scheme, in which a bound on the local error is used to select the step size. In many cases, this method is the most efficient when compared with commonly used step-size selection criteria, and it is robust for a wide range of systems providing a system-independent rule for choosing the step sizes. We find that a step-size selection method based on limiting the nonlinear phase rotation of each step is not efficient for many optical-fiber transmission systems, although it works well for solitons. We also tested a method that uses a logarithmic step-size distribution to bound the amount of spurious four-wave mixing. This method is as efficient as other second-order schemes in the single-channel dispersion-managed soliton system, while it is not efficient in other cases including multichannel simulations. We find that in most cases, the simple approach in which the step size is held constant is the least efficient of all the methods. Finally, we implemented a method in which the step size is inversely proportional to the largest group velocity difference between channels. This scheme performs best in multichannel optical communications systems for the values of accuracy typically required in most transmission simulations. View full abstract»

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  • Improved techniques for the measurement of phase error in waveguide based optical devices

    Publication Year: 2003 , Page(s): 198 - 205
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (687 KB) |  | HTML iconHTML  

    Phase-error measurement using an incoherent light source and information in the resulting interferograms is an effective technique for characterizing waveguide-based optical devices. We propose a new analysis scheme that utilizes Hilbert transformation along with an increased data sampling rate of the interferogram. The higher data sampling rate makes the measurement more noise tolerant and improves the accuracy of the resulting phase determination to 0.2°. This technique enables a "windowing" analysis method that is capable of testing waveguides with very small path length differences. We also present a new analysis tool for device characterization by creating a "phase trend" plot that detects different optical modes propagating within the waveguide. View full abstract»

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  • Measured temporal and spectral PMD characteristics and their implications for network-level mitigation approaches

    Publication Year: 2003 , Page(s): 79 - 86
    Cited by:  Papers (19)  |  Patents (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (667 KB) |  | HTML iconHTML  

    Signal degradation due to polarization-mode dispersion (PMD) effects may become significant for signaling rates of 10 Gb/s, 40 Gb/s, and beyond. To assess the utility of various PMD mitigation schemes, temporal and spectral measurements of differential group delay (DGD) were made on 95 km of buried standard single-mode fiber over an 86-d period to determine the distribution and rate of change of high-DGD events. As expected, statistical analysis of variations in DGD indicate that excursions from the mean DGD by factors of 3.7 or higher have very low probability. For this link, the DGD varied slowly with time (having a drift time of about 3.4 d) and rapidly with wavelength. The DGD data agree well with results of similar experiments reported in the literature. Statistical analysis of the measured DGD data shows that high-DGD episodes will be exceedingly rare and short-lived. The impact of PMD on network operations is explored and approaches to ensure network reliability are reviewed for network operators given the task of transporting high-bit-rate channels over fiber links with known PMD characteristics. View full abstract»

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  • Investigations of the spectral sensitivity of long period gratings fabricated in three-layered optical fiber

    Publication Year: 2003 , Page(s): 264 - 268
    Cited by:  Papers (11)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (331 KB) |  | HTML iconHTML  

    Long period gratings (LPGs) were written into a progressive three-layered (PTL) monomode optical fiber. The spectral sensitivity was experimentally measured with respect to temperature and the surrounding refractive index, and compared with theoretical predictions. The behavior of the devices suggests that this type of fiber may be useful as a means of reducing the sensitivity of LPGs to the surrounding medium and for simultaneous temperature and refractive index sensing. View full abstract»

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  • Quantitative estimates of mode coupling and differential modal attenuation in perfluorinated graded-index plastic optical fiber

    Publication Year: 2003 , Page(s): 111 - 121
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1385 KB) |  | HTML iconHTML  

    The performance of plastic optical fiber is greatly influenced by the related but distinct effects of mode coupling and differential modal attenuation (DMA). We establish a method for estimating the matrix that governs both of these effects and allows us to distinguish the two. We obtain partial quantitative estimates of this matrix for a particular graded-index plastic optical fiber (GI-POF). The sample we studied exhibited strong but incomplete mode coupling over 100-m lengths, while DMA was largely limited to a centerline defect. We show that much of the loss of the fiber can be attributed to mode coupling between mode groups with similar effective indexes. View full abstract»

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  • High-speed directly modulated Fabry-Perot and distributed-feedback spot-size-converted lasers suitable for passive alignment, unisolated operation, and uncooled environments up to 85°C

    Publication Year: 2003 , Page(s): 69 - 78
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (867 KB)  

    Semiconductor lasers with narrow far fields are highly desirable because they can be directly coupled to fiber with high-coupling efficiency, eliminating the cost of lenses and extra packaging. Because of their smaller size, they facilitate more compact transmitters, and since they can be used unpackaged, they enable complex integrated optoelectronic devices. We describe the design, fabrication, and performance characteristics of our family of spot-size-converted (SSC) devices with narrow far fields designed for directly modulated (2.5 and 10 Gb/s) uncooled (85°C) use. The design consists of a conventional active region buried heterostructure laser coupled to an expander region (consisting of a loosely confining waveguide) through a laterally tapered etch of the active layers. This basic design achieves far fields of ∼16×10 degrees, suitable for coupling ∼50 percent of the emitted light into a flat cleaved fiber. Distributed feedback (DFB) 1.3- and 1.5-μm devices, and 1.3-μm Fabry-Perot (F-P) lasers have been implemented in this technology. The devices have dc thresholds from 8-12 mA at 25°C and 35-45 mA at 85°C, with peak power of >15 mWs over temperature, all similar to non-SSC devices with the same active regions. Both SSC F-Ps and DFBs demonstrate bandwidths of >7 GHz and wide-open eyes at 85°C, and reliability suitable for uncooled use. With the DFB device, we also demonstrate a wide open 10-Gb/s eye pattern at room temperature. The laser on a submount demonstrates coupling to a fiber in a v-groove of ∼25% using passive alignment, and sufficient tolerance to back reflection to enable transmission over at least 15 km with typical drive circuitry. Analysis shows that these lasers also have a factor of two improvements in alignment tolerance compared to standard devices in a typical lensed system. The expander impacts the dc and dynamic characteristics of the SSC F-P through the increase in cavity size. The dc and dynamic characteristics of SSC DFBs and standard DFBs are very similar, demonstrating that expander-related absorption and mode transition loss has been almost eliminated in this structure. The SSC-DFBs are, thus, the preferred device for high-speed applications. To ou- r knowledge, the 1.3-μm lasers described are the first SSC devices fully suited for use as an uncooled 2.5-Gb/s transmitters up to 85°C. The combination of a tailored narrow far field with an edge emitting structure rivals vertical cavity lasers in alignment tolerance for low-cost packaging with superior dynamic and thermal performance. View full abstract»

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  • Design, fabrication, and testing of an integrated Si-based light modulator

    Publication Year: 2003 , Page(s): 228 - 235
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (726 KB) |  | HTML iconHTML  

    We have fabricated and characterized a novel Si-based light modulator working at the standard communication wavelength of 1.5 μm. It consists of a three-terminal bipolar mode field effect transistor integrated with a silicon rib waveguide on epitaxial Si wafers. The modulator optical channel is embodied within its vertical electrical channel. Light modulation is achieved moving a plasma of carriers inside and outside the optical channel by properly biasing the control electrode. The carriers produce an increase of the Si absorption coefficient. The devices have been fabricated using clean-room processing. Detailed electrical characterization and device simulations confirm that strong conductivity modulation and plasma formation in the channel are achieved. The plasma distribution in the device under different bias conditions has been directly derived from emission microscopy analyses. The device performances in terms of modulation depth will be presented. View full abstract»

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  • Space mapping technique for design optimization of antireflection coatings in photonic devices

    Publication Year: 2003 , Page(s): 281 - 285
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (422 KB) |  | HTML iconHTML  

    Space-mapping (SM) technique is applied for design optimization of antireflection (AR) coatings for photonic devices such as the semiconductor optical amplifiers (SOA). The approximate and efficient transfer matrix method (TMM) serves as the coarse model for design optimization, whereas the time-intensive and accurate finite-difference time-domain (FDTD) method is used as the fine model for model calibration. A mapping is established between the parameter spaces of the coarse and the fine models so that the fine model design becomes the inverse mapping of the optimized coarse model design. Remarkable performance of the SM technique in terms of efficiency and accuracy in the design optimization is demonstrated by way of examples. It is shown that, in the context of multilayer coating design, the desired broadband ultralow reflectivities can be obtained within three fine model (FDTD) calculations. View full abstract»

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  • Photosensitivity and application with 157-nm F2 laser radiation in planar lightwave circuits

    Publication Year: 2003 , Page(s): 140 - 148
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (461 KB) |  | HTML iconHTML  

    Photosensitivity studies of germanosilica planar waveguides were carried out with short-wavelength 157-nm light from an F2 laser. More than a 5×10-3 refractive-index change was induced in a nonuniform index profile concentrated near the cladding-core interface and confirmed by an atomic force microscopy in 157-nm radiated fiber. This profile geometry narrows with the laser exposure to offer practical application in trimming phase errors and controlling birefringence in frequency domain modulators where a 1.7×10-3 effective index change and a 5×10-4 birefringence change were induced, respectively. The 157-nm photosensitivity response is more than 15 times stronger than that by a 248-nm KrF laser and more than twofold stronger than that by a 193-nm ArF laser. View full abstract»

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  • Calculation of APD impulse response using a space- and time-dependent ionization probability distribution function

    Publication Year: 2003 , Page(s): 155 - 159
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (634 KB) |  | HTML iconHTML  

    A new approach is described for calculating the current impulse response of an avalanche photodiode, allowing for an arbitrary model for carrier transport and also for an arbitrary distribution of ionization events in space and time, following carrier injection. The technique can evaluate both the mean current response and its variance. We find that while the effects of diffusion on mean current are small, the enhanced speed to early ionization can speed up the avalanche process significantly. View full abstract»

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  • Closed WKB formulas for weakly guiding optical fibers

    Publication Year: 2003 , Page(s): 286 - 292
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (549 KB) |  | HTML iconHTML  

    This paper proposes closed WKB formulas for cutoff frequencies and the propagation constant of weakly guiding optical fibers. For the sake of simplicity, only nondecreasing refractive profiles are taken into consideration. The formulas arise from an approximation of the WKB integral, which preserves the general validity requirements of the method. View full abstract»

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  • Investigation of electromagnetic field in a layer with time-varying medium by Volterra integral equation method

    Publication Year: 2003 , Page(s): 305 - 314
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (980 KB) |  | HTML iconHTML  

    The application of the Volterra integral equation method for investigations of the interaction of electromagnetic fields with a one-dimensional time-varying dielectric layer is considered. The medium permittivity inside the layer may change in time owing to a nonlinearity as well as to extrinsic sources. Original software for the computer modeling of such an interaction is developed. Numerical results are presented and a comparison made between the accuracy and stability of integral equation method and the finite-difference time-domain (FDTD) method. View full abstract»

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  • Interrogation of wavelength multiplexed fiber Bragg gratings using spectral filtering and amplitude-to-phase optical conversion

    Publication Year: 2003 , Page(s): 127 - 131
    Cited by:  Papers (6)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (281 KB) |  | HTML iconHTML  

    A technique for interrogating multiplexed FBG sensors using all-fiber low-cost devices is demonstrated. It is based on spectral filtering employing a fused biconical wavelength-division multiplexer and on amplitude-to-phase optical conversion to perform power referencing. Four FBG sensors are wavelength multiplexed in the network, and a 3-nm-wide tunable optical filter is employed at the detection block for sensor demultiplexing. With this technique an operation range of more than 2 nm is demonstrated for the sensors with achievable wavelength static resolution ranging from 1.9 to 13.4 pm/Hz12/ with no observable hysteresis. As for power referencing, the system is proven to be unaffected by power variations as high as 75% of the total power launched by the source. Finally, output-phase variations due to crosstalk are shown to be under 1% of the total output phase range, with more than 29-dB optical isolation between channels. View full abstract»

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Aims & Scope

The Journal of Lightwave Technology contains articles on current research, applications and methods used in lightwave technology and fiber optics.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Peter J. Winzer
Alcatel-Lucent Bell Labs