SESAM mode-locked Nd:fiber laser at 920 nm for nonlinear optical microscopy.

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• All-polarization-maintaining (PM) fiber lasers offer enhanced stability and beam quality.
• Passively mode-locked lasers are crucial for generating ultrashort pulses.
• Nd-doped fiber lasers are versatile gain media for various wavelengths.

Purpose of the Study:

• To design, model, and characterize a novel diode-pumped, all-PM fiber laser.
• To achieve stable, passively mode-locked operation at 920 nm.
• To explore the laser's suitability for advanced microscopy techniques.

Main Methods:

• Utilized a semiconductor saturable absorber mirror (SESAM) for passive mode-locking.
• Employed diode-pumping for efficient laser operation.
• Characterized laser output including repetition frequency, power, bandwidth, intensity noise, and timing jitter.

Main Results:

• Achieved a diode-pumped, all-PM fiber laser operating at 920 nm in a passively mode-locked regime.
• Generated pulse trains with 18.5 MHz repetition frequency and 0.26 mW average output power.
• Demonstrated ultra-low intensity noise (0.04%) and timing jitter (<2 ps) over a broad bandwidth.
• Successfully locked the laser's repetition frequency to an Yb-doped oscillator.

Conclusions:

• The developed Nd:fiber laser exhibits excellent noise and jitter performance.
• The laser's frequency-locking capability enables advanced applications like stimulated Raman scattering microscopy.
• This all-PM fiber laser represents a significant advancement for spectroscopic and imaging applications.