The Periodic Table of Oscilloscope Tools: Analyze (Part III)

We're nearing the end of our tour of the Periodic Table of Oscilloscope Tools, our way of presenting our broad palette of oscilloscope tools in a concise, clear fashion. In this installment, we'll finish up the Analyze grouping, by far the largest on the Periodic Table.

The Fundamentals of Coherent Signals

Figure 1: These two coherent light waves have
a constant phase offset

Optical communications have come a long way from the simple direct detection of amplitude-modulated transmissions. Today's long-haul optical networks make use of coherent detection, and for good reason. Using coherent detection, receivers can track the phase of the incoming signal and thereby extract any information conveyed using phase and/or frequency modulation. Thus, coherent detection facilitates much higher capacity without using more bandwidth.