Novel Optical Sampling Oscilloscope Using Envelope Detection Triggering Method

We propose a new triggering method for an optical sampling oscilloscope (OSO). In this method, a high-frequency clock signal is not required because a fundamental sine-wave signal, which is extracted directly from the cross-correlation signal, is used for triggering. The frequency of the fundamental sine-wave signal is several kilohertz to several tens of kilohertz, corresponding to the repetition frequency of an envelope of the cross-correlation signal.This method simplifies the measurement operation and achieves accurate eye-diagram waveform measurements of transmission signals without expensive clock-recovery circuits. This paper explains the basic principle of this method. Furthermore, we describe a configuration and the results of measurement stability and jitter generated by triggering in the OSO using this new method.