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Bandwidth enhancement in semiconductor lasers with strong light injection is examined and reported.

In this paper, we present for the first time general analytical solutions of the static Green's functions for shielded and open arbitrarily multilayered media. The analytical formulas for the static Green's functions, which are expressed in the form of the Fourier series or the Fourier integrals, have simple form and are applicable to arbitrary number of the dielectric layers. The derivation of the formulas is primarily based on a technique by which a recurrence relation between L layers and L + 1 layers is developed. Green's functions for a three-layered dielectric structure are given as an example of the general formulas. These general analytical solutions will provide a new and efficient tool to the analysis of the multilayered medium structures.

A new method of analysis called the partial-boundary element method (p-BEM) is proposed for the analysis of striplines with arbitrary cross-sectional dielectric in multi-layered media. By using a Green's function that satisfies the boundary conditions of a relevant structure with multi-layered media and introducing a concept of the equivalent charge density, the p-BEM formulates a potential integral and boundary integral equations only on partial-boundaries such as the surface of the arbitrary cross-sectional dielectric. The number of the equations needed to be formulated is much less than in the conventional BEM. Numerical results of analysis are presented for two kinds of striplines: 1) with a rectangular dielectric ridge and 2) with an embedded rectangular dielectric in three-layered media.

In this paper we investigate the propagation and dispersion characteristics of picosecond electrical pulses in a suspended coplanar waveguide (SCPW) and show that the SCPW is a very promising transmission structure for ultra-short pulses with picosecond and subpicosecond durations, compared with conventional coplanar waveguides (CPWs). Numerical results of modal dispersion of the SCPW are presented and compared to those of the conventional CPW, and a field coupling theory is employed to explain the evolution in the dispersion behavior. An evaluation based on the numerical analysis shows that the SCPW with properly controlled dispersion can result in an improvement of about 5 times in pulse transmission capability than the conventional CPW. The propagation of picosecond pulses along the SCPW has been studied by both computer simulations and experimental measurements, both showing a substantial suppression in pulse distortion compared to the case of conventional coplanar waveguides.

This paper applies an improved version of the point-matching method for estimating the cutoff frequencies of the dominant mode of a class of polarization-maintaining composite optical fibers and shows an existence condition for nonzero cutoff frequencies of the dominant mode. [ABSTRACT FROM AUTHOR]

Compared to microstrip lines, suspended strip lines have characteristics of low loss and weak dispersion and are being applied to millimeters-wave circuits. Suspended strip line structures analyzed in the past have been limited to those which have the same substrate width as that of the outer conductor. However, in many practical cases, the side-walls of the outer conductor have grooves to support a dielectric substrate. The authors have already proposed a quasi-TEM wave analysis method based on a variational approach using the spline function for trial functions to estimate the effects of these grooves on the characteristics of single-conductor suspended strip lines. This paper applies this method to characterize broad-' side coupled strip lines which are necessary to design millimeter-wave directional coupplers and filters, and considers the effects of the grooves on characteristic impedance, propagation velocity, and coupling coefficient. The proper selection of spline knots is discussed to attain various characteristic constants with high accuracy. [ABSTRACT FROM AUTHOR]

Presents correction in the November 2003 issue of the periodical "IEEE Journal of Quantum Electronics" for the article "Cavity Resonance Shift and Bandwidth Enhancement in Semiconductor Lasers With Strong Light Injection," which was published in previous issue of the periodical.