摘要:

Recent progress in research into two-section laser diodes/amplifiers and their applications in optical communications and photonic switching is reviewed. The laser diodes/amplifiers could be used as optical pulse generators, wavelength-tunable light sources, bistable devices, optical wavelength filters, detectors and optical wavelength convertors. Thanks to ongoing work in this area, practical optical functional devices able to fulfil the needs of system designers are closer at hand than ever before.

DOI:10.1049/ip-j.1993.0002

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A theoretical model for spontaneous emission in self-pulsing semiconductor lasers is proposed and an analytical expression given for the excess noise factor. Statistical properties of emitted light pulses due to spontaneous noise are studied numerically and pump current conditions for optimal pulse stability are defined. The model proposed its applicable to the analysis of fluctuation properties of self-pulsing lasers at frequencies near pulsation repetition frequency.

DOI:10.1049/ip-j.1993.0003

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A multimode formalism has been used to estimate the intrinsic modulation index of semiconductor lasers. The calculated value of 1.3 is in agreement with the available experimental evidence. Pure FM operation is inhibited and a small AM component is present in the self locked FM supermode.

DOI:10.1049/ip-j.1993.0004

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The rate equations of a modulated single-mode semiconductor laser are solved numerically to determine the region in the bias current against frequency plane where pattern effects are important. Pattern effects are avoided by biasing just below threshold, but they are important for high-frequency modulation and bias current above threshold.

DOI:10.1049/ip-j.1993.0005

出版商:IEE    

年代:1993

数据来源: IET

摘要:

Grating coupled surface emitting distributed feedback lasers are analysed by our recently developed model. The model takes into account spontaneous emission, the longitudinal variation of carrier concentration and that of photon density, calculated by a self-consistent technique. The emission spectrum and near and far field radiation patterns are determined as a function of the injection current and external optical feedback. It is found that a single lobed far field radiation pattern is favoured by asymmetric coating of the facets. In addition, the phase margin to achieve a single lobed radiation profile can be increased by increasing the amplitude of the reflection.

DOI:10.1049/ip-j.1993.0006

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The authors present a simple model of a travelling wave semiconductor optical amplifier with an appreciable degree of saturation. The model uses a particular way of linearising the total carrier recombinationR(N) to find useful expressions for the saturation parameter and/or the carrier lifetime. By combining these expressions and the gain measurements realised, it is possible to establish the dependence between the mentioned parameters and the input optical power.

DOI:10.1049/ip-j.1993.0007

出版商:IEE    

年代:1993

数据来源: IET

摘要:

In the numerical simulation of buried heterostructure (BH) lasers a fast, accurate method is essential to solve the wave equation. The paper compares the effective index method with the weighted index method and it is found that if modes other than the fundamental are to be considered the effective index method becomes inaccurate. The authors investigate several methods for solving the algebraic eigenvalue equation which results from the effective and weighted index methods. It is found that a method based on inverse iteration with successive eigenvalue refinement is highly efficient, with good initial approximations to the eigenvalue and eigenvector obtained using a Sturm sequence and inversion.

DOI:10.1049/ip-j.1993.0008

出版商:IEE    

年代:1993

数据来源: IET

摘要:

Free-space radiation modes are used to determine a new formula for the main mode reflectivity of a multicoated semiconductor laser facet at normal incidence. The results are shown to compare favourably with exact values, and to provide some unification for the Fresnel methods.

DOI:10.1049/ip-j.1993.0009

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A radiation mode technique, first used in optical fibre theory, is used to study the propagation of waves in practical optoelectronic devices. The method is validated against other techniques for step discontinuities, tapers, air-gaps and Y junctions. The solution deals successfully with reflected waves and is found to be accurate enough to be used for design purposes.

DOI:10.1049/ip-j.1993.0010

出版商:IEE    

年代:1993

数据来源: IET

摘要:

It is well known that in analysing symmetric directional coupler problems only half of the cross-section need be considered, thereby shortening CPU time and reducing the computer memory needed. This simplicity disappears in the case of important devices such as the asymmetric directional coupler. The paper proposes a new methodology which allows fine-mesh finite difference analysis for the modal indices and field profiles of the two lowest supermodes of such an asymmetric structure.

DOI:10.1049/ip-j.1993.0011

出版商:IEE    

年代:1993

数据来源: IET