CEO phase /CEP
First paper in 1999 on carrier-envelope offset (CEO) phase control (also referred to as CEP control):
A novel concept for absolute optical frequency measurement and ultrashort pulse generation: Download Ref. [113] (PDF, 258 KB)
A modelocked laser oscillator produces a pulse train with pulses separated by the pulse repetition rate period TR and described by the pulse envelope A(t), the electric field E(t).

Modelocked pulse train in the time domain: carrier envelope offset (CEO) phase

Modelocked pulse train in the frequency domain: frequency comb with two degrees of freedom with the pulse repetition frequency frep and the CEO frequency fCEO.