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ABSTRACT: We investigate the performance and DSP resource requirements of digitally generated OFDM and sinc-shaped Nyquist pulses. The two multiplexing techniques are of interest as they offer highest spectral efficiency. The comparison aims at determining which technology performs better with limited processing capacities of state-of-the-art FPGAs. It is shown that a novel Nyquist pulse shaping technique, based on look-up tables requires lower resource count than equivalent IFFT-based OFDM signal generation while achieving similar performance with low inter-channel guard-bands in ultra-dense WDM. Our findings are based on a resource assessment of selected DSP implementations in terms of both simulations and experimental validations. The experiments were performed with real-time software-defined transmitters using a single or three optical carriers.
Optics Express 12/2012; 20(26):B543-51. · 3.59 Impact Factor
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ABSTRACT: Photonic integration requires a versatile packaging technology that enables low-loss interconnects between photonic chips in three-dimensional configurations. In this paper we introduce the concept of photonic wire bonding, where polymer waveguides with three-dimensional freeform geometries are used to bridge the gap between nanophotonic circuits located on different chips. In a proof-of-principle experiment, we demonstrate the fabrication of single-mode photonic wire bonds (PWB) by direct-write two-photon lithography. First-generation prototypes allow for efficient broadband coupling with average insertion losses of only 1.6 dB in the C-band and can carry wavelength-division multiplexing signals with multi-Tbit/s data rates. Photonic wire bonding is well suited for automated mass production, and we expect the technology to enable optical multi-chip systems with enhanced performance and flexibility.
Optics Express 07/2012; 20(16):17667-77. · 3.59 Impact Factor
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R Bonk,
G Huber,
T Vallaitis,
S Koenig, R Schmogrow,
D Hillerkuss,
R Brenot,
F Lelarge,
G-H Duan,
S Sygletos,
C Koos,
W Freude,
J Leuthold
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ABSTRACT: The capability of semiconductor optical amplifiers (SOA) to amplify advanced optical modulation format signals is investigated. The input power dynamic range is studied and especially the impact of the SOA alpha factor is addressed. Our results show that the advantage of a lower alpha-factor SOA decreases for higher-order modulation formats. Experiments at 20 GBd BPSK, QPSK and 16QAM with two SOAs with different alpha factors are performed. Simulations for various modulation formats support the experimental findings.
Optics Express 04/2012; 20(9):9657-72. · 3.59 Impact Factor
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R Schmogrow,
D Hillerkuss,
S Wolf,
B Bäuerle,
M Winter,
P Kleinow,
B Nebendahl,
T Dippon,
P C Schindler,
C Koos,
W Freude,
J Leuthold
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ABSTRACT: We demonstrate for the first time transmission of 54 Gbit/s and 48 Gbit/s over 44 km and 150 km, respectively, utilizing an optical bandwidth of only 3 GHz. We used polarization division multiplexed 512QAM and 256QAM modulation formats in combination with Nyquist pulse shaping having virtually zero roll-off. The resulting spectral efficiencies range up to 18 bit/s/Hz and 16 bit/s/Hz, respectively. Taking into account the overhead required for forward error correction, the occupied signal bandwidth corresponds to net spectral efficiencies of 14.4 bit/s/Hz and 15 bit/s/Hz, which could be achieved in a wavelength division multiplexed network without spectral guard bands.
Optics Express 03/2012; 20(6):6439-47. · 3.59 Impact Factor
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R. Schmogrow,
B. Nebendahl,
M. Winter,
A. Josten,
D. Hillerkuss,
S. Koenig,
J. Meyer,
M. Dreschmann,
M. Huebner,
C. Koos,
J. Becker,
W. Freude,
J. Leuthold
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ABSTRACT: We examine the relation between optical signal-to-noise ratio (OSNR), error vector magnitude (EVM), and bit-error ratio (BER). Theoretical results and numerical simulations are compared to measured values of OSNR, EVM, and BER. We conclude that the EVM is an appropriate metric for optical channels limited by additive white Gaussian noise. Results are supported by experiments with six modulation formats at symbol rates of 20 and 25 GBd generated by a software-defined transmitter.
IEEE Photonics Technology Letters 02/2012; · 2.19 Impact Factor
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R Schmogrow,
M Winter,
M Meyer,
D Hillerkuss,
S Wolf,
B Baeuerle,
A Ludwig,
B Nebendahl,
S Ben-Ezra,
J Meyer,
M Dreschmann,
M Huebner,
J Becker,
C Koos,
W Freude,
J Leuthold
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ABSTRACT: Nyquist sinc-pulse shaping provides spectral efficiencies close to the theoretical limit. In this paper we discuss the analogy to optical orthogonal frequency division multiplexing and compare both techniques with respect to spectral efficiency and peak to average power ratio. We then show that using appropriate algorithms, Nyquist pulse shaped modulation formats can be encoded on a single wavelength at speeds beyond 100 Gbit/s in real-time. Finally we discuss the proper reception of Nyquist pulses.
Optics Express 01/2012; 20(1):317-37. · 3.59 Impact Factor
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Computing, Networking and Communications (ICNC), 2012 International Conference on; 01/2012
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R Schmogrow,
M Winter,
D Hillerkuss,
B Nebendahl,
S Ben-Ezra,
J Meyer,
M Dreschmann,
M Huebner,
J Becker,
C Koos,
W Freude,
J Leuthold
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ABSTRACT: Real-time OFDM transmitters breaking the 100 Gbit/s barrier require high-performance, usually FPGA-based digital signal processing. Especially the Fourier transform as a key operation of any OFDM system must be optimized with respect to performance and chip area utilization. Here, we demonstrate an alternative to the widely adopted fast Fourier transform algorithm. Based on an extensive yet optimized use of pre-set look-up tables, our FPGA implementation supports fast reconfigurable channel equalization and switching times in the nanosecond range without re-loading any code. We demonstrate the potential of the concept by realizing the first real-time single polarization OFDM transmitter generating a 101.5 Gbit/s data stream by modulating 58 subcarriers with 16QAM.
Optics Express 06/2011; 19(13):12740-9. · 3.59 Impact Factor
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D. Hillerkuss, R. Schmogrow,
T. Schellinger,
M. Jordan,
M. Winter,
G. Huber,
T. Vallaitis,
R. Bonk,
P. Kleinow,
F. Frey, [......],
A. Oehler,
K. Weingarten,
T. Ellermeyer,
J. Lutz,
M. Moeller,
M. Huebner,
J. Becker,
C. Koos,
W. Freude,
J. Leuthold
Nature Photonics 05/2011; 5(6):364-371. · 29.28 Impact Factor
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D. Hillerkuss, R. Schmogrow,
T. Schellinger,
M. Jordan,
M. Winter,
G. Huber,
T. Vallaitis,
R. Bonk,
P. Kleinow,
F. Frey, [......],
A. Oehler,
K. Weingarten,
T. Ellermeyer,
J. Lutz,
M. Moeller,
M. Huebner,
J. Becker,
C. Koos,
W. Freude,
J. Leuthold
Nature Photonics. 05/2011; 5:364.
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ABSTRACT: Impact of SOA α-factor on dynamic range limitation decreases for higher-order modulation formats leading to undistinguishable performances of bulk and QD SOAs. Results are supported by experiments at 20 GBd BPSK, QPSK and 16-QAM.
Optical Fiber Communication Conference and Exposition (OFC/NFOEC), 2011 and the National Fiber Optic Engineers Conference; 01/2011
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ABSTRACT: Progress in electronic data processing enables software-defined optical (SDO) transmission. Modulation formats and symbol rates are set by software-controlled field programmable gate arrays (FPGA). We demonstrate a real-time SDO transmitter for 8 modulation formats, which can be swapped in 5 ns. Single-polarization 64QAM symbol generation at 28 GBd allows transmitting 168 Gbit/s real-time data. We further present a 101.5 Gbit/s single-polarization OFDM transmitter based on real-time FPGA processing, where we modulate 58 subcarriers with 16QAM data. For terabit OFDM reception, optical pre-processing is required to demultiplex high-bitrate signals down to lower-bitrate tributaries, which then can be processed digitally. We discuss a 10.8 Tbit/s receiver employing an all-optical fast Fourier transform to demultiplex 75 optical subcarriers modulated with 16QAM-formated symbols at a rate of 16 GBd.
Transparent Optical Networks (ICTON), 2011 13th International Conference on; 01/2011
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R. Schmogrow,
D. Hillerkuss,
M. Dreschmann,
M. Huebner,
M. Winter,
J. Meyer,
B. Nebendahl,
C. Koos,
J. Becker,
W. Freude,
J. Leuthold
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ABSTRACT: We demonstrate a software-defined real-time optical multiformat transmitter. Here, eight different modulation formats are shown. Data rate and modulation formats are defined through software accessible look-up tables enabling format switching in the nanosecond regime without changing the transmitter hardware. No data are lost during the switching process. SP-64 quadrature amplitude modulation at 28 Gbd has been generated and tested. This allows us to generate a 336-Gb/s real-time pseudorandom bit sequence in a dual polarization setup.
IEEE Photonics Technology Letters 12/2010; · 2.19 Impact Factor
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R. Schmogrow,
D. Hillerkuss,
M. Dreschmann,
M. Hübner,
M. Winter,
J. Meyer,
B. Nebendahl,
C. Koos,
J. Becker,
W. Freude,
J. Leuthold
[show abstract]
[hide abstract]
ABSTRACT: We demonstrate a software-defined real-time optical multiformat transmitter. Here, eight different modulation formats are shown. Data rate and modulation formats are defined through software accessible look-up tables enabling format switching in the nanosecond regime without changing the transmitter hardware. No data are lost during the switching process. SP-64 quadrature amplitude modulation at 28 Gbd has been generated and tested. This allows us to generate a 336-Gb/s real-time pseudorandom bit sequence in a dual polarization setup.
IEEE Photonics Technology Letters. 11/2010; 22(21):1601.
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R. Schmogrow,
D. Hillerkuss,
M. Dreschmann,
M. Huebner,
M. Winter,
J. Meyer,
B. Nebendahl,
C. Koos,
J. Becker,
W. Freude,
J. Leuthold
IEEE Photonics Technology Letters 11/2010; · 2.19 Impact Factor
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R. Freund,
M. Nölle,
C. Schmidt-Langhorst,
R. Ludwig,
C. Schubert,
G. Bosco,
A. Carena,
P. Poggiolini,
L. Oxenløwe,
M. Galili, [......],
D. Hillerkuss, R. Schmogrow,
W. Freude,
J. Leuthold,
A.D. Ellis,
F.C.G. Gunning,
J. Zhao,
P. Frascella,
S.K. Ibrahim,
N.M. Suibhne
International Conference on Transparent Optical Networks (ICTON); 06/2010
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D. Hillerkuss,
T. Schellinger, R. Schmogrow,
M. Winter,
T. Vallaitis,
R. Bonk,
A. Marculescu,
J. Li,
M. Dreschmann,
J. Meyer, [......],
B. Resan,
K. Weingarten,
T. Ellermeyer,
J. Lutz,
M. Möller,
M. Hübner,
J. Becker,
C. Koos,
W. Freude,
J. Leuthold
Conference on Optical Fiber Communication (OFC); 03/2010
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D Hillerkuss,
T Schellinger, R Schmogrow,
M Winter,
T Vallaitis,
R Bonk,
A Marculescu,
J Li,
M Dreschmann,
J Meyer, [......],
B Resan,
K Weingarten,
T Ellermeyer,
J Lutz,
M Möller,
M Huebner,
J Becker,
C Koos,
W Freude,
J Leuthold
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ABSTRACT: OFDM data with line rates of 5.4 Tbit/s or 10.8 Tbit/s are generated and decoded with a new real-time all-optical FFT receiver. Each of 75 carriers of a comb source is encoded with 18 GBd QPSK or 16-QAM. ©2010 Optical Society of America OCIS codes: (060.4510) Optical communications; (060.1660) Coherent communications(070.2025) Discrete optical signal processing.
