This thesis investigates the possibility of canceling chirp in an actively modelocked semiconductor laser using a DFB structure. The chirp is caused by the nonlinearity of the diode, namely, the line-width enhancement factor, a. The mode-locking equations are formed, and the postulated solution is a gaussian pulse shape. The diode is modeled primarily using the rate equations for carrier and ph...

We demonstrate multiple bandgap integration on the hybrid silicon platform using quantum well intermixing. A broadband DFB laser array and a DFB-EAM array are realized on a single chip using four bandgaps defined by ion implantation enhanced disordering. The broadband laser array uses two bandgaps with 17 nm blue shift to compensate for gain roll-off while the integrated DFB-EAMs use the as-gro...

In this paper, based on the coupled-mode and carrier rate equations, a dynamic model and numerical analysis of a multi quantum well (MQW) chirped distributed feedback semiconductor optical amplifier (DFB-SOA)  all-optical flip-flop is precisely derived. We have analyzed the effects of strains of QW and MQW and cross phase modulation (XPM) on the dynamic response, and rise and fall times of the ...

In this paper we summarize the results [1] on the development of high power 1300 nm ridge waveguide Fabry-Perot and distributed-feedback (DFB) lasers. Improved performance of MOCVD grown InGaAsP/InP laser structures and optimization of the ridge waveguide design allowed us to achieve more than 800 mW output power from 1300 nm single mode Fabry-Perot lasers. Despite the fact that the beam aspect...

Sleep-promoting neurons in the dorsal fan-shaped body (dFB) of Drosophila are integral to sleep homeostasis, but how these cells impose sleep on the organism is unknown. We report that dFB neurons communicate via inhibitory transmitters, including allatostatin-A (AstA), with interneurons connecting the superior arch with the ellipsoid body of the central complex. These "helicon cells" express t...

Efficient and reliable models for semiconductor distributed feedback (DFB) lasers design and optimization are highly desirable. An innovative dynamic model for accurate simulations of DFB lasers is proposed in this paper. The developed algorithm is based on a system of coupled partial differential equations which is solved by the finite element method (FEM). No approximation is assumed and obta...

A tunable circularly polarized distributed feedback (DFB) laser based on reflection grating configuration was realized in a solution of 4- (dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) doped methanol. Chiral photonic DFB structures with tunable photonic bandgap were generated by controlling the state of polarization of the two interfering pump beams. The dual-peak lasing ...

The effects of 2 growth regulators, diflubenzuron (DFB) and OMS 2017, on the ability of females Aedes aegypti to become infected with Molinema dessetae was studied under laboratory conditions. OMS 2017 and DFB had no effect on either the amount of blood ingested or the microfilarial load. The infective potential of females that survived DFB treatment was significantly greater than untreated fem...

The effects of 2 growth regulators, diflubenzuron (DFB) and OMS 2017, on the ability of females Aedes aegypti to become infected with Molinema dessetae was studied under laboratory conditions. OMS 2017 and DFB had no effect on either the amount of blood ingested or the microfilarial load. The infective potential of females that survived DFB treatment was significantly greater than untreated fem...

In the centrosymmetric dinuclear title compound, [Tb(2)(C(7)H(3)F(2)O(2))(6)(C(10)H(8)N(2))(2)], the Tb(III) ion is coordinated by an N,N'-bidentate 2,2'-bipyridine mol-ecule, and two O,O'-bidentate 2,4-difluoro-benzoate (dfb) anions. One of the latter also bonds to the second Tb(III) centre through one of its O atoms. The third dfb anion bonds to one Tb atom from each of its O atoms. Thus, the...