High power chirped pulse Yb fiber amplifier seeded by mode-locked fiber laser oscillator with multimode interference based saturable absorber

Advances in Ultrafast Fiber Lasers for Multiphoton Microscopy in Neuroscience

“…After the final stage, they increased pulse energy up to 1 µJ at 0.5 MHz [16]. The schematic representation of CPA is shown in Figure 4a, which consists of (1) an ultrafast mode-locked laser oscillator that generates seeding pulses; (2) a pulse stretcher that extends the seeding pulse to the picosecond level; (3) pre-amplifiers and power amplifiers; (4) a pulse picker used to adjust the repetition rate; and (5) a pulse compressor that dechirps the amplified pulse to nearly transform-limited pulse width [15,52].…”

“…In order to verify the presence of an ASE signal while scaling the power in the power amplifier, the output spectrum of the laser signal is measured and the pump spectrum exactly peaks at 975 nm and the strength of the ASE spectrum is very low, which is within the acceptable limit (Figure 6c). Figure 6d represents the output power versus input pump power of the power amplifier's simulated and experimental characteristics [52].…”

“…It has been recently discovered that artificial SAs have limitations in terms of stability and broadband laser development. Currently, the focus has shifted to developing new broadband SAs based on different fiber structures, such as no core (NC), graded-index multimode (GIM), and step-index multimode (SIM) [52] fibers, as well as extraordinary 2D materials, such as black phosphorus (BP), MXene, and transition metal dichalcogenides (TMDs) [65] that have emerged with their own set of advantages. These SAs can be made with 3D printing technology.…”