Patent ID: 7940817

Claim:
A method for stabilizing a mode-locked pulse train to an electrical signal, the method comprising: producing a light beam from a pump to provide gain in a rare-earth doped fiber; directing said light beam to a semiconductor saturable absorber mirror used to produce said mode-locked pulse train; optically modulating a saturable loss of said semiconductor saturable absorber mirror by said light beam from said pump to stabilize said mode-locked pulse train, said modulation comprising modulating said pump by an electrical signal to modulate said light beam, said electrical signal comprising a continuous component and a high frequency signal component, and a frequency of said high frequency signal is substantially the same as a repetition rate of said mode-locked pulse train; and optimizing the level of the continuous component and the high frequency signal component, wherein the light beam emitted by said pump is used both for exciting rare-earth atoms and to optically modulate the losses of the saturable absorber.