DCA Optical Waveform Analyzer
Jul 2011Agilent Technologies Inc.Request Info
SANTA CLARA, Calif., July 7, 2011 — Agilent Technologies Inc. has introduced a measurement solution for optical transmitter compliance testing on its 86100D digital communications analyzer (DCA). The solution offers high-bandwidth optical waveform analysis and increased accuracy.
The DCA provides a new approach, called system impulse response correction (SIRC), that enables multimode optical receivers with bandwidths >25 GHz and single-mode receivers with near-100-GHz bandwidths. Optical reference receivers will have suitable frequency response for testing next-generation storage and telecommunications components and systems.
These capabilities allow R&D engineers to visualize and quantify the quality of their designs for optical components and systems, and manufacturing engineers can be assured of the accuracy of their optical transceiver compliance testing.
Next-generation optical transmitters compatible with multimode optical fiber are expected to operate soon at data rates in the 25-Gb/s range. With large multimode-compatible photodetectors, optical oscilloscope channels have been unable to provide the bandwidth necessary for accurate waveform analysis.
With SIRC, the company provides an advanced calibration capability that can boost the measurement bandwidth of the 86105D from 20 to >25 GHz. SIRC also enables the analyzer to be configured as a multimode reference receiver for standards-based compliance testing at both 25- and 28-Gb/s rates. It can provide a quad-port reference receiver for 4 × 25-Gb/s 100-Gb Ethernet testing.
Optical reference receivers are an essential element in a standardized test method to verify that optical transmitters will interoperate in a communications system. Some deviation from an ideal frequency response is allowed to facilitate production of the receivers, but this deviation can cause variation in measurement results from test system to test system. By performing an impulse-response analysis, the oscilloscope channel’s frequency response is precisely determined. Using this information, the 86100D DCA can correct frequency response deviations and provide waveform results as if the reference receiver were ideal.
Using SIRC calibration, the analyzer’s mainframe can make real-time corrections to the raw waveforms. The displayed signal appears as if it had been acquired with a system that has an ideal frequency response. SIRC enables an ideal reference receiver for virtually any data rate within the physical limits of the system. The user can increase or decrease the effective bandwidth of the measurement system approximately 50% from the nominal hardware capabilities.
SIRC accurately preserves random signal components such as jitter and noise. General signal processing techniques can incorrectly filter these signal components, resulting in an incorrect waveform display.