Abstract:
Design of InGaAs-InAlAs multiple-quantum-well (MQW) optical modulators is described by employing the step segment method (SSM), the three-dimensional beam propagation met...Show MoreMetadata
Abstract:
Design of InGaAs-InAlAs multiple-quantum-well (MQW) optical modulators is described by employing the step segment method (SSM), the three-dimensional beam propagation method (3-D BPM), and the lumped element circuit model. Optical waveguides are treated as materials with complex refractive index. Field distributions, power confinement factors ( Gamma factors), propagation losses, etc. are calculated. It is found that the overlap integral is needed to calculate accurately coupling losses between the optical waveguides and single-mode fibers in place of the simple Gaussian beam-coupling formula and that quasi-single-mode propagation can be obtained even for thick core structures. Design procedures for the driving voltage, and frequency characteristics are also discussed.<>
Published in: IEEE Journal of Quantum Electronics ( Volume: 28, Issue: 1, January 1992)
DOI: 10.1109/3.119517
Citations are not available for this document.
Cites in Patents (4)Patent Links Provided by 1790 Analytics
1.
Ramadan, Tarek A., "COUPLER MULTIPLEXER PERMUTATION SWITCH"
Inventors:
Ramadan, Tarek A.
Abstract:
A coupler-multiplexer permutation switch (CMPS) integrates multiplexng and switching functions on a single substrate. It has a single-mode/multi-mode backward coupler followed by a digital optical switch (DOS). In the CMPS, the single-mode waveguide channels are phase-matched through a grating with the corresponding, backward-propagating modes of a multi-mode waveguide. The different modes are subsequently separated in a digital optical switch. Different permutations are obtained by electronically controlling an effective-index distribution of DOS output waveguides.
Assignee:
THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK
Filing Date:
20 April 2001
Grant Date:
01 May 2007
Patent Classes:
Current U.S. Class:
385050000, 385018000, 385037000, 398087000
Current International Class:
G02B0062930, G02B0063400, H04J0140200
2.
Kawano, Kenji, "ULTRA HIGH SPEED SEMICONDUCTOR OPTICAL MODULATOR WITH TRAVELING WAVE ELECTRODE"
Inventors:
Kawano, Kenji
Abstract:
A wideband semiconductor electro-absorption optical modulator including a semiconductor core shorter in absorption-peak wavelength than a wavelength of optical signal, and an electrode for applying an electric signal to absorb the optical signal by shifting the absorption-peak wavelength to a long wavelength region when a voltage is applied, wherein an electric signal input port and an electric signal output port are disposed so that the electrode is constructed in the form of a traveling-wave electrode, and a total thickness of non-doped layers including the semiconductor core is reduced to decrease a driving voltage. Degradation of optical modulation bandwidth and reflection characteristics of the electric signal caused by mismatching of characteristic impedance to an outer circuit are reduced by decreasing an interaction length of the electric signal and the optical signal. Further, mismatching of characteristic impedance is corrected by adjusting a doping concentration of a p-type or n-type doped layer located above or beneath the semiconductor core.
Assignee:
NIPPON TELEGRAPH & TELEPHONE CORP
Filing Date:
16 October 1997
Grant Date:
30 November 1999
Patent Classes:
Current U.S. Class:
359248000, 359254000, 359276000
Current International Class:
G02F0010150000
3.
Bissessur, Hans; Mestric, Roland; Duchet, Christian, "WAVELENGTH DEMULTIPLEXER"
Inventors:
Bissessur, Hans; Mestric, Roland; Duchet, Christian
Abstract:
The demultiplexer comprises a diffraction space defined by a reception surface coupled to a grating. In order to obtain output waves of flattened spectral response, the input waveguide and the reception surface are dimensioned so that the input wave diffracts over said surface and presents a plurality of secondary lobes. The demultiplexer is particularly applicable to optical communications systems with wavelength multiplexing.
Assignee:
ALCATEL ALSTHOM COMPAGNIE GENERALE D'ELECTRICITE
Filing Date:
24 December 1996
Grant Date:
12 May 1998
Patent Classes:
Current U.S. Class:
385037000, 385046000
Current International Class:
G02B0063400000
4.
Bissessur, Hans; Mestric, Roland; Duchet, Christian, "Wavelenght-multiplexer"
Inventors:
Bissessur, Hans; Mestric, Roland; Duchet, Christian
Abstract:
Optical wavelength demultiplexer using focusing diffraction grating The input waveguide (Ge) comprises a guide layer of size and refractive index giving a lateral confinement factor of at least 95%. It enters a diffraction space (Ce) which is a star coupler connected by a grating formed with guides (gi) of different wavelengths to a second star coupler (Cs). A focusing surface (Zf) is bounded by the second coupler and receives waves as a function of their wavelength. The receiving surface (Ze) together with the input guide is made with dimensions such that the diffracted wave of a given input is formed on the surface such that its amplitude as a function of position has a part at least of several secondary lobes.
Assignee:
ALCATEL ALSTHOM COMPAGNIE GENERALE D'ELECTRICITE
Filing Date:
19 December 1996
Grant Date:
09 July 1997
Patent Classes:
Current International Class:
G02B0061220000, G02B0061200000, G02B0062800000, G02B0063400000, H04J0140000000, H04J0140200000
