The Tektronix 80C05 Optical Sampling Module is designed to test long wavelength (1520--1580 nm) signals. This module is intended to be used as a test and measurement tool for high bandwidth telecommunications with its high optical bandwidth >40 GHz. It has three user-selectable optical bandwidths; 20 GHz, 30 GHz and 40 GHz, or one reference receiver response; OC-192/STM-64 for 9.953 Gb/s Sonet/SDH standards. Specifications. Number of input channels: 1 optical. Effective wavelength range, typical: 1520 nm to 1580 nm. Internal fiber diameter: 9 ??m/125 ??m single mode. Optical return loss: >30 dB. Absolute maximum nondestructive optical input: 20 mW average power; 60 mW power at wavelength with highest relative responsivity. Maximum operating ranges: to 30 mW displayed limits, not including offset. However, signal limit is 10 mW average optical power, 20 mW displayed peak power at wavelength with highest relative responsivity. Calibrated wavelengths: 1550 nm ??20 nm. Main-instrument display vertical scale factors: 3 mW per division (max), 30 ??W per division (min). Vertical offset range: ??15 mW offset relative to center of waveform display (5 divisions from either top or bottom of waveform display). Rise time, typical: 40 GHz <2 ps, 30 GHz <6 ps, 20 GHz <5 ps, OC-192/STM-64 47 ps ??10 ps.