Picture of Fred Buchali

Fred Buchali

Stuttgart, Germany


FRED BUCHALI received the diploma degree in electrical engineering in 1988 and the PhD degree in 1991 from Humboldt-University Berlin. During his PhD he worked on InGaAs/InP p-i-n photodiodes for fibre-optic communication. 1992 Fred Buchali joined Alcatel-Lucent Germany. He was involved in development of high speed pin photodiodes including packaging. Since 1999 he works with optical transmission systems group, where he investigated the mitigation of transmission impairments in 10, 40 and 100 Gb/s systems by optical, analog and digital electronic means. His current research interests cover coherent systems for 1Tb/s and beyond using higher level modulation based on single carrier and multi carrier approaches.

Selected Articles and Publications

High Data Rate Tomlinson-Harashima Precoding (THP) Based PAM Transmission

DCI Field Trial Demonstrating 1.3-Tb/s Single-Channel and 50.8-Tb/s WDM Transmission Capacity


Novel Optical Field Reconstruction for IM/DD with Receiver Bandwidth Well Below Full Optical Signal Bandwidth

DCI Field Trial demonstrating 1.3-Tb/s Single-Channel and 50.8-Tb/s WDM Transmission Capacity

Single Sideband Transmission Employing a 1-to-4 ADC Frontend and Parallel Digitization

1.2Tbit/s Single Channel and 45Tbit/s WDM Field Transmission

Faster-than-Nyquist PAM-4 transmission based on Tomlinson-Harashima precoding

A SiGe HBT BiCMOS 1-to-4 ADC frontend supporting 100 GBaud PAM4 reception at 14 GHz digitizer bandwidth

Transmission Link Optimization for Coherent 4 Tb/s Extended Reach Transmission

5×510 Gbps Single-Polarization Direct-Detection WDM Transmission over 80 km of SSMF

Flexible IM/DD Beyond Bandwidth Limitation for Data Center Optical Interconnects

Beyond 400 Gb/s Direct Detection over 80km for Data Center Interconnect Applications

A SiGe HBT BiCMOS 1-to-4 ADC frontend enabling low bandwidth digitization of 100 GBaud PAM4 data

Simulation and Experimental Demonstration of an IM-DD System Enabled by End-to-End Deep Learning

50 Gb/s PAM-4 Transmission over 80-km SSMF without Chromatic Dispersion Compensation

Optical-amplifier-less transmission of 92 GBd PAM-4 signal using 80 GSa/s DAC/ADC

3.6-Tbps Duobinary 16-QAM Transmission with Improved Tolerance to Cascaded ROADM Filtering Penalty

1.6Tbps WDM Direct Detection Transmission with Virtual-Carrier over 1200km

1.6Tbps WDM Direct Detection Transmission with Virtual-Carrier over 1200km

1.6 Tbps Virtual-Carrier Assisted WDM Direct Detection Transmission over 1200 km

Duobinary IQ Modulation Schemes for C- and O-band PAM4 Direct Detect Systems

Distributed Transmission and Spatially-Coupled Coding in Multi-Point to Point Networks

8×256Gbps Virtual-Carrier Assisted WDM Direct-Detection Transmission over a Single Span of 200km

Transmit Filter Optimization for Improved Performance of Time-Frequency Packing System

Flexible Optical Transmission close to the Shannon Limit by Probabilistically Shaped QAM

Electronically Subcarrier Multiplexed PM-32QAM with Optimized FEC Overhead

Nonlinear mitigation using probabilistically shaped real-valued modulation formats

800 Gbit/s dual channel transmitter with 1.056 Tbit/s gross rate

Single carrier 1.2 Tbit/s transmission over 300 km with PM-64 QAM at 100 GBaud

Advanced C plus L-Band Transoceanic Transmission Systems Based on Probabilistically Shaped PDM-64QAM

Electronically subcarrier multiplexed PM-32QAM with optimized FEC overheads

Advanced C+L-Band Transoceanic Transmission Systems Based on Probabilistically-Shaped PDM-64QAM

Higher-Order Modulation Formats - Concepts and Enabling Devices

1.72 Tbs Virtual-Carrier Assisted WDM Direct-Detection Transmission over 200km

Flexible bitrate systems for long haul transmission

Experimental Demonstration of Capacity Increase and Rate-Adaptation by Probabilistically Shaped 64-QAM

Exploring and Experimenting With Shaping Designs for Next-Generation Optical Communications

768Gbit/s dual-polarization 64QAM transmission at 64Gbaud over 160km SSMF applying soft-FEC decoding

Improved Flexibility in Rate and Reach by Time-Frequency Packed QPSK

100 GSa/s BiCMOS DAC supporting 400 Gb/s dual carrier transmission

800 Gb/s Dual Channel Transmitter with 1.056 Tb/s gross rate

Nonlinear Tolerant Probabilistically Shaped Real-Valued Modulation

A 62Tb/s Transoceanic Transmission Experiment Using Probabilistically-Shaped PDM-64QAM

Study of subband multiplexing at 54 GHz modulation bandwidth for 16QAM and probabilistic shaped 64QAM

Probabilistic Shaped QAM for Reach and Spectral Efficiency Adaptation

Reach Increasse for High Capacity Optical Transmission Systems by Probabilistic Shaping

Field demonstration of 1 Tb/s superchannel transmission supported by probabilistic shaped constellations

Improvement of Bandwidth Limitation Tolerance for High-speed PAM-4 Transmission Using Turbo Equalizer

Inter-Channel Crosstalk Compensation for Time-Frequency Packing Systems

1.2 Tbit/s (64 QAM at 100 GBaud) transmission over 300 km

Inter-Channel Crosstalk Cancellation for WDM Time-Frequency Packing System

Single Carrier, Single Polarization 168 Gb/s PAM8 over 80 km below HD-FEC for Data Center Interconnects

80 GBd 16 QAM Reception with Time Switched Dual Frequency Local Oscillator 80 GSa/s 33 GHz Bandwidth Oscilloscope

Tradeoff between Geometric and Probabilistic Shaping for a 64 Points Modulation

Technologies for Terabit Transponders

5×240 Gb/s WDM Direct Detection Transmission over 80 km with a Spectral Efficiency of 5.25 bits/s/Hz

Beyond 400 Gb/s Direct Detection over 80km for DCI Applications

Beyond 100 GBaud Transmission Supported by a 120 GSa/s CMOS Digital to Analog Converter

System implementation of a 112 GSa/s 1-to-4 ADC frontend

16×200 Gbps Virtual Carrier Assisted DD Transmission over 80 km with a SiGe BiCMOS 1-to-4 ADC Front-End and 14 GHz of Digitizer Bandwidth

A 112-GS/s 1-to-4 ADC front-end with more than 36-dBc SFDR and 28-dB SNDR up to 43-GHz in 130-nm SiGe BiCMOS

Transmission of 90 Gbd 32 QAM over 480 km of SSMF with Kramers-Kronig Detection

DCI Field Trial demonstrating 1.3-Tb/s Single-Channel and 50.8-Tb/s WDM Transmission Capacity

1.52 Tb/s single carrier transmission supported by a 128 GSa/s SiGe DAC

1.11 Tb/s/lambda and 18.9 Tb/s WDM transmission over DCI distances supported by CMOS DACs

Flexible optical transmission

Terrestrial Transmission Reach Doubling at record spectral efficiency flexibility for 400 Gb/s and 600 Gb/s Supported by variable (non)-pragmatic square QAM Formats

Single Carrier 1.2 Tbit/s Transmission over 300 km with PM-64 QAM at 100 GBaud

Assessment of probabilistically shaped higher order QAM

Probabilistic shaping: a technique for reach extension of QAM systems with superior flexibility