Agrawal, N., Bornholdt, C., Franke, D., Hoffmann, D., Kappe, F.
Electro-absorptive long wavelength (Lambda = 1550 nm) semiconductor modulators with low drive voltage are indispensable components for future high bit-rate communication networks. Recently,...
Round, A.R., Franke, D., Moritz, S., Huchler, R., Fritsche, M., Malthan, D., ...
There is a rapidly increasing interest in the use of synchrotron small-angle X-ray scattering (SAXS) for large-scale studies of biological macromolecules in solution, and this requires an adequate...
V. Vashook, D. Franke, L. Vasylechko, J. Zosel, J. Rebello, ...
Journal article
A. Round, D. Franke, S. Moritz, R. Huchler, M. Fritsche, ...
Journal article
Franke, D., Harde, P., Kreissl, J., Möhrle, M., Rehbein, W., Künzel, H., ...
MOVPE-grown InAs quantum dots (QDs) implemented as active layers in 1.55 micrometer emitting InGaAsP/InP broad-area laser devices show improved characteristics with respect to previous MOVPE-based...
Microcrystalline silicon formation by silicon nanoparticles. (2008)
Schierning, G., Theissmann, R., Wiggers, H., Sudfeld, D., Ebbers, A., Franke, D., ...
Journal of Applied Physics, 103(2008) S.084305/1-6
Franke, D., Moehrle, M., Boettcher, J., Harde, P., Sigmund, A., Kuenzel, H.
InAs quantum dots (QDs) on InP were implemented as active layers in laser structures completely grown by metal organic vapor phase epitaxy (MOVPE). In laser structures due to growth of the upper InP...
Franke, D., Harde, P., Böttcher, J., Möhrle, M., Sigmund, A., Künzel, H.
InAs quantum dots (QD) on InP emitting at 1.55 micrometer grown by using conventional MOVPE sources were investigated. Aiming at their implementation in 1.55 micrometer laser structures thermal...
Detection of cracks in silicon wafers and solar cells by ultrasonic lock-in thermography (2004)
Rakotoniaina, J.P., Breitenstein, O., Hejjo, Al Rifai, Franke, D., Schneider, A.
Iron doping behaviour in InP grown by LP-MOVPE in the presence of tertiarybutylchloride (2003)
Paraskevopoulos, A., Franke, D., Harde, P., Gouraud, S.
Aiming at selective regrowth, the effect of Tertiarybutylchloride (TBC1) on the electrical properties of LP-MOVPE grown Fe-doped InP layers was investigated in dependence of growth temperature and...
Surface quality of InP etched with tertiarybutylchloride in an MOVPE reactor (2003)
Franke, D., Sabelfeld, N., Ebert, W., Harde, P., Wolfram, P., Grote, N.
In-situ etching of InP with tertiarybutylchloride (TBC) under MOVPE conditions was investigated with respect to etching profiles, surface morphology, and lateral etching uniformity. Etching of mesa...
MOVPE-based in-situ etching of InP epitaxial heterostructures (2002)
Wolfram, P., Franke, D., Ebert, W., Grote, N.
We summarize our experimental results on MOVPE-based etching of InP and related (InGa)(AsP) materials using tertiarybutylchloride (TBCl) as precursor. The impact of various process parameters on etch...
Discrete supervisory control of switched linear systems (2000)
This contribution deals with the synthesis of discrete supervisory control for switched linear systems. Via two successive approximation steps, this hybrid control problem is transformed into a...
Discrete supervisory control of switched linear systems (2000)
Franke, D., Moor, T., Raisch, J.
This contribution deals with the synthesis of discrete supervisory control for switched linear systems. Via two successive approximation steps, this hybrid control problem is transformed into a...
Comparison of MOVPE-based Zn diffusion into InGaAsP/InP using H2 and N2 carrier gas (2000)
Schroeter-Janssen, H., Roehle, H., Franke, D., Bochnia, R., Harde, P., Grote, N.
The indiffusion of Zn into InGaAsP layers was studied using a MOVPE-based diffusion process. Hydrogen and nitrogen were alternatively employed as carrier gas to compare their effect on the diffusion...
Monolithically integrated 1.5 mu m/1.3 mu m transceiver modules for full-duplex operation (1999)
Hamacher, M., Heidrich, H., Kaiser, R., Albrecht, P., Ebert, W., Franke, D., ...
1.5/1.3 mu m transceiver-photonic integrated circuits (PICs) with in-line and Y-junction architecture including a 1.3- mu m wavelength-selective photodetector building block have been fabricated. The...
Hybrid Resource Allocation Problems - A Laboratory Case Study (1999)
Franke Frick Holm, D. Franke, K. Frick, H. Holm, T. Moor
this paper has been initiated by shipyard industry. Ship-building requires a large number of welding seems to be carried out by a relatively small number of co-operating automated robots. In the...
Thermal crosstalk of integrated multiwavelength transmitters (1998)
Fidorra, F., Franke, D., Mohrle, M., Rehbein, W., Sigmund, A., Stenzel, R., ...
Simulations and experimental results on thermal crosstalk of integrated ridge waveguide DFB multiwavelength laser transmitter sources are presented. The thermal resistance of the laser to heat sink...
Post-growth Zn diffusion into InGaAs/InP in a LP-MOVPE reactor (1998)
Franke, D., Reier, F.W., Grote, N.
MOVPE based Zn contact diffusion into InGaAs using DMZn as source material was investigated. Maximum hole densities above 1*1020 cm-3 could reproducibly be attained. To achieve this, the presence of...
Evaluation of defect densities on LP-MOVPE grown InGaAsP in dependence of InP substrate type (1997)
Although an assessment of growth defects appears to be a very complex matter due to the various growth and substrate parameters and the statistics involved this study has shown that the substrate...
Highly reproducible and defect-free MOVPE overgrowth of InGaAsP-based DFB gratings (1997)
The paper reports on a study aiming to develop a highly reproducible process for the MOVPE overgrowth of first-order gratings made by reactive ion etching in InGaAsP. MOVPE parameters were...
Jahn, E., Agrawal, N., Pieper, W., Franke, D., Weber, H.G., ...
A Sagnac interferometer consisting of a semiconductor laser amplifier and a 3 dB coupler monolithically integrated within a waveguide loop mirror is fabricated and its app
Monolithically integrated nonlinear interferometers for all-optical switching (1996)
Jahn, E., Agrawal, N., Pieper, W., Franke, D., Furst, W., ...
We report on the development of monolithically integrated InGaAsP active/passive waveguide interferometers for all-optical switching including both Sagnac and Mach-Zehnder configurations.
Jahn, E., Agrawal, N., Pieper, W., Franke, D., Furst, W., ...
A Sagnac interferometer consisting of a semiconductor laser amplifier and a 3 dB coupler monolithically integrated within a waveguide loop mirror is fabricated and its application as a 20 Gbit/s...
Jahn, E., Agrawal, N., Arbert, M., Franke, D., Ludwig, R., ...
We demonstrate all-optical error-free demultiplexing of 10, 20 and 40 Gbit/s to 5 Gbit/s by using a monolithically integrated Mach-Zehnder interferometer with two semiconductor laser amplifiers.
Roehle, H., Schroeter-Janssen, H., Harde, P., Franke, D.
Fe doping profiles in InP layers grown by low-pressure metalorganic vapor phase epitaxy (LP-MOVPE) were investigated by secondary ion mass spectroscopy. Different pre-treatments of the InP substrates...
Jahn, E., Agrawal, N., Arbert, M., Franke, D., Ludwig, R., ...
The authors demonstrate all-optical error-free demultiplexing of 10, 20 and 40 Gbit/s to 5 Gbit/s data signals by using a monolithically integrated Mach-Zehnder interferometer with two semiconductor...
Fast 2*2 Mach-Zehnder optical space switches using InGaAsP-InP multiquantum-well structures (1995)
Agrawal, N., Weinert, C.M., Mekonnen, G.G., Franke, D., Bornholdt, C., ...
We report fast 2*2 Mach-Zehnder optical space switches by using quantum confined Stark effect in InGaAsP-InP multiquantum-well structures that are ultracompact, require low voltages, and employ a...
Kaiser, R., Fidorra, F., Trommer, D., Malchow, S., Albrecht, P., Franke, D., ...
Polarization diversity heterodyne receiver PICs including a tunable 4-section DBR laser as a local oscillator have been successfully fabricated for the first time. PIC design and fabrication are...
Feiste, U., As, D.J., Ehrhardt, A., Mohrle, M., Franke, D.
The performance of the extracted clock is characterized. The initial transient behaviour of the clock is measured when a long sequence of zero bits is present in the injected signal. The dephasing of...
Kaiser, R., Fidorra, F., Heidrich, H., Albrecht, P., Rehbein, W., Malchow, S., ...
For the first time we present the integration of a tunable buried four-section DBR-laser butt coupled to a directional coupler based on semi-insulating strip loaded (InGaAsP/InP):Fe waveguides by...
2*2 optical space switches using InGaAsP/InP MQW structures for 10-GHz applications (1994)
Agrawal, N., Franke, D., Weinert, C.M., Bornholdt, C.
Summary form only given. In this paper we demonstrate InGaAsP-InP MQW 2*2 optical space switches that show excellent dc switching performance and are capable of operation at and beyond 10 GHz. Both...
Monolithically integrated polarisation diversity heterodyne receivers on GaInAsP/InP (1994)
Kaiser, R., Trommer, D., Fidorra, F., Heidrich, H., Malchow, S., Franke, D., ...
Polarisation diversity heterodyne receiver OEICs including a tunable four-section DBR laser as a focal oscillator have been successfully fabricated for the first time. OEIC design and fabrication are...
Akustische Untersuchungen an Schallabsorptionselementen fuer Ventilatoren. (1993)
Franke, D. (1), Neise, W., Költzsch, P. (2), Preuß, U. (2), Walden, F. (2)
Agrawal, N., Franke, D., Grote, N., Reier, F.W., Schroeter-Janssen, H.
The authors report on MOVPE growth and characterization of InGaAs/In(GaAs)P and InGaAsP/InP/InAlAs multi-quantum-well structures for electro-optic switching devices, which require abrupt...
Agrawal, N., Hoffmann, D., Franke, D., Li, K.C.
Recently, a novel optical modulator heterostructure has been introduced based on voltage controlled electron transfer from a reservoir to a closely spaced quantum well. It has proven to exhibit large...
Lasing characteristics of InGaAs/InGaAsP MQW structures grown by low-pressure MOVPE (1991)
Rosenzweig, M., Ebert, W., Franke, D., Grote, N., Sartorius, B., Wolfram, P.
InGaAs/InGaAsP MQW SC lasers for 1.55 mu m emission wavelength with different numbers of quantum wells have been fabricated using low-pressure MOVPE. Photoluminescence and gain spectra and threshold...
Optical thickness mapping of InGaAsP/InP layers (1991)
Sartorius, B., Brandstattner, M., Wolfram, P., Franke, D.
A two-wavelengths transmission method is presented for measuring the thickness of epitaxial layers with a resolution of better than 10 nm. The measuring speed is high which for the first time makes...
Agrawal, N., Hoffmann, D., Franke, D., Li, K.C., Clemens, U., Witt, A., ...
The authors demonstrate for the first time electro-optic modulation due to voltage controlled phase space filling by electron transfer in modulation doped MOVPE grown InGaAsP/InP multiple quantum...
Characteristics of 1.5 µm InGaAs/InGaAsP MQW lasers (1990)
Duser, H., Fidorra, F., Franke, D., Mohrle, M., Rosenzweig, M., Wolfram, P., ...
The paper discusses long-wave MQW lasers for emissions in the range of 1.23 to 1.55 µm which have been produced as conventional InAsP/InP double heterostructures and the reasons for their relatively...
Doping and diffusion behaviour of Fe in MOVPE grown InP layers (1990)
Franke, D., Harde, P., Wolfram, P., Grote, N.
Doping and diffusion characteristics of Fe in semi-insulating AP-MOVPE grown InP layers were assessed using the SIMS technique. Fairly flat Fe depth profiles and a linear doping curve were obtained...
Implanted-collector InGaAsP/InP heterojunction bipolar transistor (1989)
Su, L.M., Grote, N., Schumacher, P., Franke, D.
A novel structure for an InP-based heterojunction bipolar transistor is proposed and demonstrated which not only provides technological advantages over conventional structures but is also...
Assessment of semi-insulating InP:Fe layers for substrate applications (1989)
Grote, N., Bach, H.G., Feifel, T., Franke, D., Harde, P., Sartorious, B., ...
Semi-insulating InP epi-substrates formed by epitaxial InP:Fe layers on suitable base substrates are proposed and investigated. Compared to standard commercial s.i. bulk substrates, such...
Very high purity InP layers grown by adduct-MOVPE (1989)
Wolfram, P., Reier, F.W., Franke, D., Schumann, H.
Using the adduct compound trimethylindium-trimethylphosphine (TMIn-TMP) very high purity InP layers have been grown by atmospheric pressure MOVPE (AP-MOVPE). Residual electron concentrations of less...
Pfanner, K., Franke, D., Sartorius, B., Schlak, M.
The use of a Sn-In-P melt and of InP cover wafers of different orientations to prevent thermal surface decomposition of InP substrates in liquid phase epitaxy has been compared. An almost equivalent...
Luminescence microscopy for quality control of material and processing (1987)
Satorius, B., Franke, D., Schlak, M.
A photoluminescence topography system is devised on the basis of an optical IR microscope. The system offers full versatility and simple operation of the microscope combined with the high sensitivity...
Integrated-optic polarisation convertor on (001)-InP substrate (1986)
Schlak, M., Nolting, H.P., Albrecht, P., Doldissen, W., Franke, D., Niggebrugge, U., ...
A novel TE/TM convertor is proposed and demonstrated which is fabricated on (001)-InP substrate and can be integrated with TE-TM phase shifters to provide a general polarisation transformation. Some...
High-efficiency phase modulators in InGaAsP/InP (1985)
Bornholdt, C., Doldissen, W., Franke, D., Krauser, J., Niggebrugge, U., ...
For an electro-optical phase modulator in InGaAsP/InP, optimized by modelling calculations, a phase-shift of 8 deg/Vmm was achieved.
Schmitt, F., Su, L.M., Franke, D., Kaumanns, R.
Describes an open diffusion technique with a thin vacuum-deposited Zn3P2 layer covered by an Al2O3 layer, Zn diffusion in (100) n-InP single crystals by this techniques was studied and...
Light guiding and electrooptical modulation in InGaAsP/InP double heterostructures (1983)
Albrecht, P., Bach, H.G., Bornholdt, C., Doldissen, W., Franke, D., Grote, N., ...
The fabrication of long rig-waveguides in the InGaAsP system with low loss suitable for integrated optics has been demonstrated. Furthermore, the authors showed, for the first time, electrooptical...
Passive optical GaInAsP/InP waveguides (1983)
Bornholdt, C., Doldissen, W., Franke, D., Grote, N., Krauser, J., Niggebrugge, U., ...
The authors have fabricated GaInAsP/InP rib waveguides with lengths of up to 7 mm and widths between 2*5 and 10 mu m. The waveguides show low losses of alpha =1.38-1.84 cm-1 at a wavelength of 1.3 mu...
Sonomorphologic evaluation of goiter in an iodine deficiency area in the Ivory Coast.
Franke, D, Filler, G, Zivicnjak, M, Kouamé, P, Ohde, I, Eckhardt, L, ...
OBJECTIVES: This study evaluated the extent of thyroid abnormalities in a remote iodine-deficient area of the Ivory Coast. METHODS: Ultrasonography was used in detecting the presence of goiter....
Sonomorphologic evaluation of goiter in an iodine deficiency area in the Ivory Coast.
Franke, D, Filler, G, Zivicnjak, M, Kouamé, P, Ohde, I, Eckhardt, L, ...
OBJECTIVES: This study evaluated the extent of thyroid abnormalities in a remote iodine-deficient area of the Ivory Coast. METHODS: Ultrasonography was used in detecting the presence of goiter....