Journal of Lightwave Technology

We fabricated a 1-GHz-spaced 16-channel arrayed-waveguide grating (AWG) by using a new AWG configuration where the path of each arrayed waveguide winds backward and forward across a 4-in diameter wafer without crossing any other waveguides. The ultra-narrow (< 1 GHz) and stable transmission bands of this AWG can be used to construct a wavelength reference standard covering the S, C, and L bands in... View full abstract»

The directional coupler is one of the most important devices in the field of integrated optics, from which other optical devices such as polarization splitters and reflectors are derived. In this paper, we present an autodesign method for polarization splitters and reflectors based on the beam propagation method and the golden section method, which can decrease the amount of computation greatly. U... View full abstract»

We demonstrate an optical channel dropping filter (OCDF) using three parallel-cascaded vertically coupled microrings with improved rolloff, bandpass flattening, and wide free spectral range (FSR) compared to a single-ring OCDF using single-mode tightly confined waveguides in both GaAs-AlGaAs and GaInAsP-InP. We achieve FSRs of 30 nm for GaAs-AlGaAs and 40 nm for GaInAsP-InP devices, which are thre... View full abstract»

We describe a high performance acoustooptic tunable filter for add-drop application and for signal equalization in WDM telecommunication crossconnects. It results from a thorough investigation in TeO2 of bulk collinear interaction, the geometry of which, particularly the direction of propagation of the acoustic wave, has been chosen in order to obtain the best compromise between the spe... View full abstract»

Photonic systems that use a variable or chirped optical wavelength and a single Mach-Zehnder modulator have been analyzed to determine the relation between optical bandwidth and spur free dynamic range. A novel wavelength insensitive biasing technique is proposed which significantly reduces the second-order distortion and increases the optical bandwidth. View full abstract»

A novel optical voltage sensor based on the electrooptic crystal multiplier is proposed and experimentally investigated. Different from the conventional bulk-type optical voltage sensor, the optical sensing unit is simply composed of an electrooptic crystal and two polarizers and does not need quarter wave-plate. By using different modulation approaches, both ac and dc voltages can be measured wit... View full abstract»

This paper describes the development of a 1.58-μm broad-band and gain-flattened erbium-doped tellurite fiber amplifier (EDTFA). First, we compare the spectroscopic properties of various glasses including the stimulated emission cross sections of the Er3+4 I132/ 4I152/ transition and the signal excited-state absorption (ESA) cross sections of the Er View full abstract»

We measured the continuous wave (CW) laser-induced damage threshold of single-mode fiber-optic connectors at 1550 nm. Clean standard physical contact and angled physical contact connectors did not show any evidence of damage for 10 min exposures of 1 W or 3 W. Defective connectors with scratched or undercut endfaces showed identical high-power tolerance as clean connectors without defects. Samples... View full abstract»

The performance of an asynchronous phase-encoded optical code-division multiple-access system is evaluated on the condition that the impact of fiber channel is neglected. Phase-encoded optical signal (pseudorandom optical signal with low intensity) is analyzed in the view of stationary random process. The pseudorandom optical signal with low intensity is seen as a sample function of a certain stat... View full abstract»

In order to relax alignment tolerances on single-mode fiber interconnection, we propose an end face treatment to realize an expanded mode fiber. This new technique consists of splicing fibers with various lengths and characteristics. The spot size and coupling properties are analyzed numerically considering the effects of gap, offset, and tilt. Low loss, wide misalignment tolerances, and low cost ... View full abstract»

The unitary transfer matrix of a fiber affected by polarization mode dispersion (PMD) is analyzed using the Stokes representation of its eigenmodes and its retardation angle, or equivalently through its Pauli coordinates. We develop a statistical theory applied to these parameters and relate it to the extensive existing literature on the statistics of the PMD vector Dynamical equations are establi... View full abstract»

This paper describes a theoretical and experimental analysis of the channel drop filter using a single defect formed near the two-dimensional (2-D) photonic crystal slab waveguide. First, we calculate the transmission spectrum of a 2-D photonic crystal waveguide and show that high transmittance for a wide wavelength range (∼60 nm) is obtained in the 1.55-μm region. We also show that a defec... View full abstract»

We analyze the role of distributed amplification in controlling timing jitter in dispersion-managed soliton systems and discuss, using analytical and numerical techniques, how timing jitter is reduced by up to a factor of two when lumped amplification is replaced by complete or partial distributed amplification. We derive an analytical expression for the timing jitter at any position within the fi... View full abstract»

A new concept for an infrared waveguide detector based on silicon is introduced. It is fabricated using silicon-on-insulator material, and consists of an erbium-doped p-n junction located in the core of a silicon ridge waveguide. The detection scheme relies on the optical absorption of 1.5-μm light by Er3+ ions in the waveguide core, followed by electron-hole pair generation by the e... View full abstract»

The polarization dependence of the coherent detection in optical frequency-domain reflectometry can be exploited to measure the local beatlength along an optical fiber. Reproducibility of the results is given for high and low polarization-mode coupling fibers, and the influence of several effects on beatlength measurement precision, such as spatial reflectometer resolution, fiber twist, and the pr... View full abstract»

We have conducted a study of potential wavelength calibration references for use as both moderate-accuracy transfer standards and high-accuracy National Institute of Standards and Technology (NIST) internal references in the 1280-1320-nm wavelength-division-multiplexing region. We found that most atomic and molecular absorption lines in this region are not ideal for use as wavelength references ow... View full abstract»

We consider a scheduling problem, which we call the scheduling and wavelength assignment (SWA) problem, arising in optical networks that are based on the wavelength-division-multiplexing (WDM) technology. We prove that the SWA problem is NP-complete for both the preemptive and the nonpreemptive cases. Furthermore, we propose two efficient approximation algorithms. The first is for the preemptive c... View full abstract»

A study of Mach-Zehnder interferometer (MZI) modulators using unetched and etched Ti:LiNbO3 waveguides has been made. A full vectorial finite-element-based mode solver was used, followed by a finite element-based solution of the Laplace equation to calculate the electrooptic effect and, subsequently, the half-wave voltage, Vπ The optical loss due to the metal electrodes wa... View full abstract»