Summary
E-mail, Web searches, text messages, bank transfers, landline phone calls, even wireless calls all spend time as pulses of light flashing through fiber-optic lines spanning tens, hundreds, or thousands of miles. Today's economy relies on these forms of high-speed communications, and NIST plays a crucial role in providing the means to test the equipment on which these communications depend by developing novel methods for calibrating optical and electrical waveforms. These methods will enable the design and qualification of current and next generation communication networks that are required to achieve true broadband access to every American citizen.
Description
Optoelectronic communications hardware translates electric currents into light waves and back again at a pace that can move data as fast as 40 gigabits per second — a speed great enough to transmit full-length digital movies across the country in something over a second. EEEL has pioneered the high-speed measurement standards and methods crucial to the functioning of high-speed communication equipment as well as other vital radar, remote sensing, wireless communications, and computer-networking hardware. Through a combination of electro-optic sampling (EOS) and covariance-based uncertainty analysis, EEEL calibrates high-speed photodiodes to be used as electrical pulse generators for characterizing high-speed test equipment in both time- and frequency-domains.
The covariance analysis creates a framework for maintaining the correlations in the uncertainties of the frequency-domain impedance measurements and mismatch corrections in the EOS measurements so that uncertainties in the time-domain can also be determined. An important application of these calibrated pulse generators is the calibration of oscilloscopes and other high-speed temporal waveform measurement systems used in the digital electronics, wireless communications, and fiber optic communications industries. When combined with the NIST Timebase Correction Software, engineers can overcome some of the bandwidth limitations of their test equipment, enabling product specifications with known uncertainties rather than the current practice of placing upper limits on signal accuracy, leading to needlessly large tolerances in high-speed components and systems.
With the prospect of faster all-optical switching equipment, engineers will need a way of measuring light-signal quality, understanding its inevitable degradation, and dynamically compensating for such impairments in the equipment sending the original signal. To this end, EEEL is measuring light signal quality as well as various forms of signal degradation in work indispensable to next-generation all-optical networking.
Collaborators
Project Staff work closely with other related projects within NIST.
Metrology for Wireless Systems
High-Speed Microelectronics
Page updated: 9/24/2009 |
