86119A Optical Sampling OscilloscopeTo address the need for speed in telecommunications systems, as is evident from research trials with 40-Gb/s and even 160-Gb/s systems, and to improve the limited bandwidth of traditional oscilloscopes for telecom applications, Agilent Technologies Inc. of Santa Rosa, Calif., developed the 86119A optical sampling oscilloscope. Aiming at bandwidth in excess of 700 GHz, the instrument's design employs a nonlinear optical crystal, periodically poled lithium niobate, to enable very fast optical sampling. The device still is operated identically to the wide-bandwidth sampling oscilloscopes that are used in high-speed communications analysis. Unlike the distorted images that conventional sampling oscilloscopes provide, and unlike using a complex optical autocorrelator, the 86119A enables researchers to easily see exactly what their signals look like. The company built the system as an addition to its 86100 DCA (digital communication analyzer) system. Enclosed in an undercarriage package that sits beneath the DCA, it down-converts a high-speed input optical signal into the range that the analyzer can view, providing an oscilloscope display. All of the DCA's built-in capabilities can be employed to analyze the signal, such as power measurements, rise and fall times, and jitter. Combined with the 86107A precision time-base reference module, a winner of last year's contest, the oscilloscope exhibits optical bandwidth in excess of 700 GHz with low intrinsic jitter. It can display nonreturn-to-zero and return-to-zero pulses, including pulse asymmetries.