Efficient Optical Time-Division Demultiplexing And Signal Regeneration
Tech ID: 10274 / UC Case 2003-386-0
In data networks employing optical time-division multiplexing (OTDM), each network node must carry out a number of key functions in order to efficiently process an optical signal that is modulated with both a data stream and timing signals. In particular, the processing of each channel within the signal requires simultaneous demultiplexing, packet add/drop, clock recovery and synchronization, and data stream regeneration. At present, incorporating all of these functions into an optical network node poses severe trade-offs between hardware complexity and cost on one hand and problems of channel ambiguity and cross-talk on the other.
Researchers at the University of California have invented OTDM node components that simplify the node architecture needed to simultaneously carry out the various channel processing functions. The UC components employ a 4-port traveling-wave electroabsorbtion modulator (TW-EAM) element, where two of the ports are used for optical signal input/output and the other two ports are used for feedback modulation of the signal. The feedback modulators in these inventions enable clock recovery from the input signal, which in turn can be used to demultiplex the signal for extracting a particular data channel or to regenerate a complete OTDM signal (see diagrams below). The UC OTDM node components can be employed in both all-optical and optoelectronic switching configurations. At 40 gigabits per second data input rates, prototypes of these inventions have shown a locking range of 200 kHz at 0 dBm optical input power and 700 kHz at 5 dBm optical input power.
Schematic diagram of clock recovery & demultiplexing, with a data channel extracted in an all-optical or optoelectronic mode.
Schematic diagram of clock recovery & signal regeneration, with the addition of a recovered timing signal to the multiplexed data channels.
These inventions will likely find use in OTDM network nodes where clock recovery is needed.
The UC OTDM node components:
- combine clock recovery with other functions to significantly reduce the complexity of the node architecture;
- achieve substantial reductions in hardware costs; and
- do not compromise node performance, processing signals without ambiguity or cross-talk.
This technology is available for licensing on a non-exclusive basis.
|United States Of America||Issued Patent||7,196,833||03/27/2007||2003-386|
|United States Of America||Issued Patent||7,184,189||02/27/2007||2003-386|
- Blumenthal, Daniel J.
- Bowers, John E.
- Chou, Hsu-Feng
- Hu, Zhaoyang
- Inohara, Ryo
- Nishimura, Kohsuke
- Usami, Masashi
ADDITIONAL TECHNOLOGIES BY THESE INVENTORS
- High-Power Pulses From Semiconductor Lasers
- Vcsels With Improved Mirror Properties
- Technique For Creating Buried Blocking Layers For Vertical-Cavity Lasers And Other Devices
- Semiconductor Hetero-Interface Photodetector
- Fused Vertical Couplers
- All Optical Label Swapping Using Two-Stage Optical Wavelength Converters
- Optical Dispersion Monitoring Technique Using Double Sideband Subcarriers
- Loss Modulated Silicon Evanescent Lasers
- Low Noise, Stable Avalanche Photodiode
- Hybrid Silicon Integrated Optical Isolator and Circulator
- Integrated Wavelength Tunable Single and Two-Stage All-Optical Wavelength Converter
- Method for Making a Metal Layer Semiconductor Laser
- Integration Of Ultra-Low Loss And Active Silicon Waveguide Layers
- Integrated Bidirectional Optical Amplifier (BOA) for Optical Interconnects
- Enhancement Of Thermoelectric Properties Through Polarization Engineering