The HP 83446B lightwave clock/data receiver is designed to extract clock and data information from digitally modulated lightwave signals at the SONET/SDH data rate of 622.08 Mb/s (OC-12/STM-4). It incorporates a high-gain avalanche photodiode (APD), gain-controlled amplifier, and clock/data recovery hybrid to deliver clean, error-free outputs from optical signals with powers as low as -28 dBm at either 1310 or 1550 nm wavelength. The HP 83446B has been designed especially for use with high-speed bit-error-ratio testers (BERTs) such as the HP 71603B or 71612A. By connecting the clock and data outputs to the corresponding inputs on the BERT's error detector, bit-error-ratio analysis can be performed directly on optical signals, making it easy to do system acceptance and BER floor analysis. The HP 83446B also has an auxiliary port which allows monitoring of the output of the APD prior to regeneration.