scholarly journals Longitudinal mode spectrum of GaAs injection lasers under high‐frequency microwave modulation

1983 ◽  
Vol 43 (7) ◽  
pp. 619-621 ◽  
Author(s):  
K. Y. Lau ◽  
Ch. Harder ◽  
A. Yariv
Keyword(s):  
High Frequency ◽  
Longitudinal Mode ◽  
Mode Spectrum ◽  
Injection Lasers ◽  
Microwave Modulation ◽  
High Frequency Microwave

scholarly journals Review on the Millimeter-Wave Generation Techniques Based on Photon Assisted for the RoF Network System

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jiangnan Xiao ◽  
Chuang Zhao ◽  
Xingxing Feng ◽  
Xu Dong ◽  
Jiangli Zuo ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Cost ◽  
Electronic Devices ◽  
Low Frequency ◽  
Digital Signal ◽  
Development Trend ◽  
Wave Generation ◽  
Communication Link ◽  
Network System ◽  
High Frequency Microwave

With the development trend of wireless and broadband in the communication link and even the whole information industry, the demand of high-frequency microwave bandwidth has been increasing. The RoF network system solves the problem of spectrum congestion in low-frequency band by providing an effective technology for the distribution of high-frequency microwave signals over optical fiber links. However, the traditional mm-wave generation technique is limited by the bandwidth of electronic devices. It is difficult to generate high-frequency and low-phase noise mm-wave signals with pure electrical components. The mm-wave communication technology based on photon assisted can overcome the bandwidth bottleneck of electronic devices and provide the potential for developing the low-cost infrastructure demand of broadband mobile services. This paper will briefly explain the characteristics of the RoF network system and the advantages of high-frequency mm-wave. Then we, respectively, introduce the modulation schemes of RoF mm-wave generation based on photon assisted including directly modulated laser (DML), external modulation, and optical heterodyne. The review mainly focuses on a variety of different mm-wave generation technologies including multifrequency vector mm-wave. Furthermore, we list several approaches to realize the large capacity data transmission techniques and describe the digital signal processing (DSP) algorithm flow in the receiver. In the end, we summarize the RoF network system and look forward to the future.

scholarly journals High-frequency homogenization for periodic media

2010 ◽  
Vol 466 (2120) ◽  
pp. 2341-2362 ◽  
Author(s):  
R. V. Craster ◽  
J. Kaplunov ◽  
A. V. Pichugin
Keyword(s):  
High Frequency ◽  
Wave Equations ◽  
Standing Waves ◽  
Low Frequency ◽  
Homogenization Theory ◽  
Periodic Media ◽  
Mode Spectrum ◽  
Bloch Mode ◽  
Long Wavelength Asymptotics ◽  
Model Equations

An asymptotic procedure based upon a two-scale approach is developed for wave propagation in a doubly periodic inhomogeneous medium with a characteristic length scale of microstructure far less than that of the macrostructure. In periodic media, there are frequencies for which standing waves, periodic with the period or double period of the cell, on the microscale emerge. These frequencies do not belong to the low-frequency range of validity covered by the classical homogenization theory, which motivates our use of the term ‘high-frequency homogenization’ when perturbing about these standing waves. The resulting long-wave equations are deduced only explicitly dependent upon the macroscale, with the microscale represented by integral quantities. These equations accurately reproduce the behaviour of the Bloch mode spectrum near the edges of the Brillouin zone, hence yielding an explicit way for homogenizing periodic media in the vicinity of ‘cell resonances’. The similarity of such model equations to high-frequency long wavelength asymptotics, for homogeneous acoustic and elastic waveguides, valid in the vicinities of thickness resonances is emphasized. Several illustrative examples are considered and show the efficacy of the developed techniques.

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