Dr. Bernd Buxbaum Profile

Dr. Bernd Buxbaum

Managing Director at pmdtechnologies AG

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Author

Publications (11)

Proceedings Article | 23 January 2002 Paper

MSM-PMD as correlation receiver in a new 3D-ranging system

Bernd Buxbaum, Rudolf Schwarte, Thorsten Ringbeck, Markus Grothof, Xuming Luan

Proceedings Volume 4546, (2002) https://doi.org/10.1117/12.453994

KEYWORDS: Modulation, Ranging, Sensors, Correlation function, Signal detection, Diodes, Receivers, Analog electronics, Photonic devices, LIDAR

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Proceedings Article | 12 December 2001 Paper

Three-dimensional intelligent sensing based on the PMD technology

Xuming Luan, Rudolf Schwarte, Zhigang Zhang, Zhanping Xu, Horst-Guenther Heinol, Bernd Buxbaum, Thorsten Ringbeck, H. Hess

Proceedings Volume 4540, (2001) https://doi.org/10.1117/12.450695

KEYWORDS: Modulation, Ranging, 3D surface sensing, Sensors, Signal processing, Electro optics, 3D metrology, Photonic devices, Sensing systems, 3D acquisition

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Proceedings Article | 27 November 2001 Paper

Wireless LAN based on optical CDMA using a new high-speed correlation receiver (MSM-PMD)

Bernd Buxbaum, Rudolf Schwarte, Thorsten Ringbeck, Markus Grothof, A. Sluiter, Jochen Frey, M. Hildebrand, Klaus David

Proceedings Volume 4530, (2001) https://doi.org/10.1117/12.449808

KEYWORDS: Logic, Receivers, Modulation, Infrared radiation, Transmitters, Computer aided design, Telecommunications, Signal detection, Correlation function, Wireless communications

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Proceedings Article | 30 May 2001 Paper

Optical GMSK modem for infrared wireless communication based on a new receiver principle in CMOS technology

Thorsten Ringbeck, Rudolf Schwarte, Bernd Buxbaum, Holger Hess

Proceedings Volume 4292, (2001) https://doi.org/10.1117/12.428035

KEYWORDS: Sensors, Receivers, Modulation, Infrared radiation, Wireless communications, Phase shift keying, Photonic devices, CMOS technology, Transmitters, Signal to noise ratio

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Proceedings Article | 24 October 2000 Paper

Diffractive optical element for an electro-optical interface based on photonic mixer device (PMD)

Wei Tai, Rudolf Schwarte, Bernd Buxbaum

Proceedings Volume 4093, (2000) https://doi.org/10.1117/12.405212

KEYWORDS: Diffractive optical elements, Vertical cavity surface emitting lasers, Receivers, Interfaces, Microlens array, Electro optics, Diffraction, Prisms, Diffraction gratings, Signal processing

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Proceedings Article | 5 September 2000 Paper

Synchronization in spread spectrum laser radar systems based on PMD-DLL

Bernd Buxbaum, Rudolf Schwarte, Thorsten Ringbeck, Xuming Luan, Zhigang Zhang, Zhanping Xu, H. Hess

Proceedings Volume 4035, (2000) https://doi.org/10.1117/12.397793

KEYWORDS: Modulation, Ranging, Correlation function, Phase shift keying, Sensors, Signal processing, CMOS technology, Telecommunications, Signal detection, Phase measurement

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This paper proposes a new optoelectronic delay locked loop (OE-DLL) and its use in optical ranging systems. The so called PMD-DLL receiver module is based on a novel electro-optical modulator (EOM), called the Photonic Mixer Device (PMD). This sensor element is a semiconductor device, which combines fast optical sensing and mixing of incoherent light signals in one component part by its unique and powerful principle of operation. Integration of some simple additional on-chip components offers a high integrated electro-optical correlation unit. Simulations and experimental results have already impressively verified the operation principle of PMD structures, all realized in CMOS technology so far. Although other technologies are also promising candidates for the PMD realization they should not be further discussed in this contribution. The principle of the new DLL approach is intensively discussed in this paper. Theoretical analysis as well as experimental results of a realized PMD-DLL system are demonstrated and judged. Due to the operation principle of sophisticated PMD devices and their unique features, a correlation process may be realized in order to synchronize a reflected incoherent light wave with an electronic reference signal. The phase shift between both signals represents the distance to an obstacle and may be determined by means of the synchronization process. This new approach, avoiding so far needed critical components such as broadband amplifiers and mixers for the detection of small photo currents in optical distance measurement, offers an extremely fast and precise phase determination in ranging applications based on the time- of-flight (TOF) principle. However, the optical measurement signal may be incoherent -- therefore a laser source is not needed imperatively. The kind of waveform used for the modulation of the light signal is variable and depends on the demands of every specific application. Even if there are plenty other alternatives (e.g., heterodyne techniques), in this contribution only so called quasi-heterodyne techniques - - also known as phase shifting methods -- are discussed and used for the implementation. The light modulation schemes described in this contribution are square-wave as well as pseudo-noise modulation. The latter approach, inspired by the wide spread use in communication as well as in position detection (e.g., IS-95 and GPS), offers essential advantages and is the most promising modulation method for the ranging approach. So called CDMA (code division multiple access) systems form a major task in communication technology investigations since the third generation mobile phone standard is also partly based on this principle. Fast and reliable synchronization in direct sequence spread spectrum communication systems (DSSS) differs hardly from the already mentioned ranging approach and will also be discussed. The possibility to integrate all components in a monolithic PMD based DLL design is also presented and discussed. This method might offer the feature to integrate complete lines or matrixes of PMD based DLLs for highly parallel, multidimensional ranging. Finally, an outlook is given with regard to further optimized PMD front ends. An estimation of the expected characteristics concerning accuracy and speed of the distance measurement is given in conclusion.

Proceedings Article | 13 December 1999 Paper

Introduction of a new opto-electrical phase-locked loop in CMOS technology: the PMD-PLL

Thorsten Ringbeck, Rudolf Schwarte, Bernd Buxbaum

Proceedings Volume 3850, (1999) https://doi.org/10.1117/12.372817

KEYWORDS: Clocks, Modulation, Optical amplifiers, Receivers, Sensors, Signal detection, Telecommunications, Oscillators, Optical communications, Networks

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Proceedings Article | 13 December 1999 Paper

PMD-PLL: receiver structure for incoherent communication and ranging systems

Bernd Buxbaum, Rudolf Schwarte, Thorsten Ringbeck

Proceedings Volume 3850, (1999) https://doi.org/10.1117/12.372813

KEYWORDS: Ranging, Telecommunications, Modulation, Receivers, Signal detection, Sensors, Signal processing, Optical communications, Integrated optics, Data transmission

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Proceedings Article | 25 September 1997 Paper

New electro-optical mixing and correlating sensor: facilities and applications of the photonic mixer device (PMD)

Rudolf Schwarte, Zhanping Xu, Horst-Guenther Heinol, Joachim Olk, Ruediger Klein, Bernd Buxbaum, Helmut Fischer, Juergen Schulte

Proceedings Volume 3100, (1997) https://doi.org/10.1117/12.287751

KEYWORDS: Modulation, CMOS technology, Charge-coupled devices, Electro optics, Diodes, Photonic devices, Sensors, Semiconductors, Electrodes, Spatial light modulators

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This paper presents first hardware implementation and investigations of a new electro-optic modulator (EOM), called the Photonic Mixer Device (PMD). The PMD is a semiconductor device combining the characteristics of fast optical sensing and modulation. Arranged to a PMD-matrix it looks like a CCD-matrix but additionally provides the depth information of each image pixel using an appropriately modulated scene illumination. Besides this feature of 3D- imaging by means of time-related correlation the PMD-chip will enable on-chip 2D-image processing by means of spatial correlation. The principle of operation of the PMD, possible technologies for realization, facilities and applications will be described. This new device offers high potential for optical sensory systems due to an amazingly simple and powerful procedure of electro-optical mixing and correlation. Both CCD and CMOS are appropriate technologies. The latter will be treated in detail as a single-element Photonic Mixer Device. Here we propose several architectures--including two quadrant (2Q)-PMDs--with readout and preprocessing circuits for both, the phase resp, time-of-flight values and the pixel intensities. Arranging PMD-pixels to a PMD-line or to a PMD-matrix will provide a new generation of flexible and powerful solid-state 3D- cameras based on time-of-flight. According to the EOM- principle, the proposed 2D-mixer requires no additional optical devices, no broadband electronic amplifiers and mixers. This solid-state PMD-array offers even more unique facilities, e.g., performing high speed spatial light modulation up to the GHz range or optical CDMA- communication. The modulation characteristic of the PMD is an important aspect of this mixer. It is associated with optimizing the layout design for the PMD, which will be presented and discussed in this paper, too. PMD test chips have been realized in CMOS technology. Some simulation and first test results of the chip are also presented. The simulation results prove the operation principle of the PMD and provide us with parameters for an optimized layout design. First experimental results verified the expected operation principle of the test PMD.

Proceedings Article | 21 March 1997 Paper

New optical four-quadrant phase detector integrated into a photogate array for small and precise 3D cameras

Rudolf Schwarte, Zhanping Xu, Horst-Guenther Heinol, Joachim Olk, Bernd Buxbaum

Proceedings Volume 3023, (1997) https://doi.org/10.1117/12.269749

KEYWORDS: Modulation, Diodes, Stereoscopic cameras, Phase shift keying, Photonic devices, Cameras, Ranging, CCD cameras, Electrons, Electro optics

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Proceedings Article | 29 October 1996 Paper

Optimization of laser ranging system in the case of colored noise

Jiangming Li, Otmar Loffeld, Rudolf Schwarte, Bernd Buxbaum, Zhanping Xu

Proceedings Volume 2904, (1996) https://doi.org/10.1117/12.256266

KEYWORDS: Ranging, Laser systems engineering, Receivers, Signal to noise ratio, Interference (communication), Linear filtering, Laser optics, Distance measurement, Signal processing, Estimation theory

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Showing 5 of 11 publications

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