Impact of Small-Signal Gain and Saturation Energy on the Mode-Locking States in an YB-Doped Fiber Laser

The impact of small signal gain go and saturation energy
$E_{\text{sat}}$
on the mode-locking states in an Yb-doped fiber was investigated. We discovered the transition states between the two stable mode-locking states with the tuning of go and
$E_{\text{sat}}$
. The transition states could exist between the transition from the double pulses state to single pulse state and the similariton to bell-shape pulse. With high
$E_{\text{sat}}$
, more transition states appeared, at which noisy breathing pulses were generated.