Mode-locked Erbium-Ytterbium Doped Fiber Laser

High Power Pulsed Fiber Lasers

Ring cavity Er-Yb doped fiber laser showing optical bench for Kerr mode locking:

Mode Locking

Mode locking is a technique to create very short periodic pulses by locking modes in phase

Additive-pulse Mode Locking

Nonlinear phase shifts in a single-mode fiber.

Pulses returning from the fiber resonator into the main laser resonator interfere with those pulses which already are in the main resonator.

Constructive interference near the peak of the pulses, but not in the wings, because the latter have acquired different nonlinear phase shifts in the fiber.

Peak of the circulating pulse is enhanced, whereas the wings are attenuated.