| 1. |
- Goobar, E., et al.
(författare)
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Measurement of a VPE-transported DFB laser with blue-shifted frequency modulation response from DC to 2 GHz
- 1988
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Ingår i: Electronics Letters. - 0013-5194 .- 1350-911X. ; 24, s. 746-747
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Tidskriftsartikel (refereegranskat)abstract
- The frequency modulation characteristics of a VPE-transported 1.53 mu;m wavelength GaInAsP-InP DFB semiconductor diode laser was measured. Below approximately 0.7 mW optical output power per facet, it exhibited a smooth, blue-shifted, frequency modulation response from DC to 2 GHz. In the modulation frequency range of 10 MHz to 100 MHz it exhibited a | Delta;f/ Delta;I| of 0.5-1.8 GHz/mA, depending on the biasing level
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| 2. |
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| 3. |
- Goobar, E., et al.
(författare)
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Pure frequency modulation or intensity modulation with suppressed frequency chirp using active Bragg reflector integrated laser
- 1989
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 25, s. 304-305
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Tidskriftsartikel (refereegranskat)abstract
- The modulation properties of a laser structure which consists of an active Bragg reflector (300 mu m) integrated with an uncorrugated gain region (600 mu m) have been measured. The laser exhibited a flat FM response and very low spurious intensity modulation when modulating the current in the Bragg reflector. Furthermore, broadband intensity modulation with suppressed frequency chirp could also be achieved. An inhomogeneous linewidth enhancement factor alpha caused by the uneven carrier density distribution between the two sections gives a qualitative explanation to our results.
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| 4. |
- Djupsjöbacka, Anders
(författare)
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Time division multiplexing using optical switches
- 1988
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Ingår i: IEEE Journal on Selected Areas in Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8716 .- 1558-0008. ; 6:7, s. 1227-1231
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Tidskriftsartikel (refereegranskat)abstract
- Design considerations are considered for optical time-division multiplexing in terms of bandwidth requirements for the modulators and switches for a particular multiplexing scheme and the corresponding drive signals are derived using a time-domain approach. It is shown that these requirements are stricter than expected from simple considerations. Different types of multiplexing schemes are analyzed and are shown to behave differently due to varying chirping properties; this chirping is also calculated. A comparison to nonmultiplexed systems is made
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| 5. |
- Taxén, Lars, et al.
(författare)
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Discrete optimization of digital filters using Gaussian adaptation and quadratic function minimization
- 1987
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Ingår i: IEEE Transactions on Circuits and Systems. - : IEEE. - 0098-4094 .- 1558-1276. ; 34:10, s. 1238-1242
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a new strategy for discrete optimization of a function F(x) is presented. Let A be the region in the n-dimensional parameter space, where F{x) is less than some constant. First, A is located and characterized by a Gaussian search process, called Gaussian adaptation. This makes it possible to approximate the behavior of F(x) over A by a quadratic function Q(x). Q(x) is then optimized for the N best discrete solutions using a branch and bound technique. Finally, these points are evaluated for the best F(x) points. By various digital filter examples it win be demonstrated that the new method is more e capable of finding good solutions than methods presented so far
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