Dr. Ralph Leppla Profile

Dr. Ralph Leppla

Engineer at Deutsche Telekom AG

SPIE Involvement:

Author

Proceedings Article | 2 October 2006 Paper

Modeling the time-variant channel of a PMD-affected WDM transmission system in respect to the temperature activity of dispersion compensating modules

Daniel Goelz, Ralph Leppla, Suzanne Salaun, Roman Glatty, Stefan Boehm, Peter Meissner

Proceedings Volume 6388, 63880K (2006) https://doi.org/10.1117/12.691256

KEYWORDS: Systems modeling, Poincaré sphere, Wavelength division multiplexing, Temperature metrology, Polarization, MATLAB, Stochastic processes, Single mode fibers, Modulation, Visual process modeling

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Proceedings Article | 25 October 2005 Paper

Optical channel model for system outage probability analysis based on PMD measurement of installed WDM links and its components

Ralph Leppla, Sascha Vorbeck, Daniel Goelz, Suzanne Salaun, Michel Joindot, Roman Glatty

Proceedings Volume 6012, 60120M (2005) https://doi.org/10.1117/12.638966

KEYWORDS: Temperature metrology, Wavelength division multiplexing, Stochastic processes, Polarization, Systems modeling, Wave plates, Numerical simulations, Picosecond phenomena, Optical amplifiers, Channel projecting optics

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Proceedings Article | 16 November 2004 Paper

Tolerances and engineering rules for ultrahigh-speed transmission systems

Sascha Vorbeck, Malte Schneiders, Ralph Leppla

Proceedings Volume 5579, (2004) https://doi.org/10.1117/12.568404

KEYWORDS: Dispersion, Optical amplifiers, Tolerancing, Raman spectroscopy, Fiber amplifiers, Complex systems, Nonlinear optics, Polarization, Phase shifts, Temperature metrology

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Proceedings Article | 25 October 2004 Paper

OTU3 transmission with 43-Gbit/s-CS-RZ signals over installed G.652 fiber infrastructure and accelerated PMD outage evaluation

Werner Weiershausen, Ralph Leppla, Ottokar Leminger, Frank Rumpf, Ralf Herber, Arnold Mattheus, Andreas Gladisch, Akira Hirano, Yoshiaki Kisaka, Yutaka Miyamoto, Shoichiro Kuwahara, Mikio Yoneyama, Masahito Tomizawa

Proceedings Volume 5596, (2004) https://doi.org/10.1117/12.580471

KEYWORDS: Polarization, Forward error correction, Picosecond phenomena, Modulation, Receivers, Wavelength division multiplexing, Single mode fibers, Optical components, Transmitters, Eye

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Proceedings Article | 25 October 2004 Paper

Tolerances and engineering rules for performance estimation and system design in 160-Gbit/s transmission systems

Sascha Vorbeck, Malte Schneiders, Ralph Leppla

Proceedings Volume 5596, (2004) https://doi.org/10.1117/12.570228

KEYWORDS: Dispersion, Optical amplifiers, Tolerancing, Raman spectroscopy, Fiber amplifiers, Complex systems, Nonlinear optics, Phase shifts, Temperature metrology, Receivers

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Proceedings Article | 8 July 2002 Paper

Current developments and future perspective on technologies for system impairments and compensations

Werner Weiershausen, Ralph Leppla, S. Vorbeck

Proceedings Volume 4872, (2002) https://doi.org/10.1117/12.475127

KEYWORDS: Optical fibers, Wavelength division multiplexing, Optical amplifiers, Receivers, Forward error correction, Transmittance, Single mode fibers, Dispersion, Optical networks, Polarization

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Due to increasing traffic demands telecommunication operators have to upgrade the transmission capacity of their networks. Since the success story of WDM in optical fiber based networks, component and system manufacturers as well as operators are dealing with the question if it is better to increase the number of WDM channels remaining at low channel bitrate or to enhance the channel line rate itself. The momentary situation is that already 10 Gbit/s based systems are installed for client traffic and are running properly. By a comparison of the technical advantages and business cases for a lot of transmission scenarios, the 10 Gbit/s solution turns out to be the preferable solution if compared to 2.5-Gbit/s-based systems. In the meantime 40GHz electronics has made severe progress so that now it seems to be possible to take the step towards the next hierarchy, the 40 Gbit/s channel rate. Nevertheless, many system manufacturers still wait with the market introduction of 40 Gbit/s, on the one hand because we observe a stagnant capacity demand this year, and on the other hand because the business case seems yet not to be competitive. One of the reasons for this is the impact of different physical limitations of fast optical fiber transmission. While the step from 2.5 to 10 Gbit/s still did not raise severe technological problems for medium distances, this is completely different for ultra long haul systems and especially for all 40-Gbit/s-based systems. While nonlinear effects still can be sufficiently managed, phenomena like, e.g., polarization-mode dispersion (PMD), chromatic dispersion mismatch, and gain tilt of optical amplifiers play an important role. Chromatic dispersion and polarization effects may vary with time so that either passive or adaptive compensation schemes may be needed in order to realize sufficiently long transmission distances. This paper will deal with different current solutions to overcome limitations from fibers and components, namely the use of special modulation formats, the use of pa

Proceedings Article | 2 January 1998 Paper

Mode-locked extended cavity laser using fiber grating and its characterization with interferometric autocorrelation measurement

Michael Fuss, Ralph Leppla, A. Mattheus, J. Reid

Proceedings Volume 3211, (1998) https://doi.org/10.1117/12.345367

KEYWORDS: Fiber lasers, Mode locking, Interferometry, Optical solitons, Solitons, Laser sources, Pulsed laser operation, Laser development, Dispersion, Reflectors

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At 1.3 mm the low group velocity dispersion of standard single mode fibre would appear to make this wavelength attractive for high bit rate transmission applications. The transmissions of optical solitons is one possible technique for reaching the high bit rates required in future transmission systems. A key component in such a system is the soliton laser source. This device must be both a stable and reliable source of optical pulses at a high bit rate. For this purpose a Mode-Locked Extended Cavity Laser (ML-ECL) using a Bragg reflector as wavelength selective feedback component for generation of a > 10 Gbit/s pulse stream has been developed operating at 1.7 GHz in the fundamental mode. A semiconductor laser chip, anti-reflection coated at one facet and high reflection coated at the other, was coupled with a lensed fibre grating. In comparison to bulk optical components the use of fibre based components ensured a better mechanical stability and about 50 times more output power. Additionally, the integration of the device is generally simplified To use this mode-locked laser as a pulse source for a high-bit-rate telecommunications system detailed analysis of the ultrashort optical pulse performance is important. Adjacent pulse interaction in a fibre link may be enhanced or suppressed depending on their non-linear phase behaviour during transmission. We briefly present a recently developed interferometric autocorrelator which is capable of detemiing both, the temporal width (FWHM) and the non-linear phase of optical pulses by assuming a certain intensity shape and extrapolation the phase. By comparing the autocorrelation traces with simulated data on the basis of a Gaussian intensity profile and a quadratic phase behaviour a linear chirp of about 25 ps within the FWHM of the optical pulses was found. The developed ML-ECL is a prototype of a laser source which will be utilised in transmission experiments in the project UPGRADE in the European ACTS programme. The realisation of optical soliton transmission at 1.3 pm over standard single mode optical fibres is a goal of this project. A field trial of 10 Gbit/s, SDH based, soliton transmission will be demonstrated at the CeBIT exhibition in Hannover in 1997. The techniques reported here play an important role in achieving the project objectives

Showing 5 of 7 publications

Conference Committee Involvement (6)

Optical Metro Networks and Short-Haul Systems IV

24 January 2012 | San Francisco, California, United States

Optical Metro Networks and Short-Haul Systems III

25 January 2011 | San Francisco, California, United States

Optical Metro Networks and Short-Haul Systems II

27 January 2010 | San Francisco, California, United States

Optical Metro Networks and Short-Haul Systems

29 January 2009 | San Jose, California, United States

Optical Transmission Systems and Equipment for Networking VI

11 September 2007 | Boston, MA, United States

Showing 5 of 6 Conference Committees

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