Sub-50 fs diode-pumped SESAM mode-locked Yb:SrF₂ laser

Area of Science:

• Laser Physics
• Quantum Optics
• Materials Science

Background:

• Yb:SrF2 lasers are promising for generating ultrashort pulses.
• Passively mode-locked lasers offer high peak powers and short pulse durations.
• Efficient diode-pumping is crucial for laser performance.

Purpose of the Study:

• To achieve sub-50 fs pulse generation from a passively mode-locked Yb:SrF2 laser.
• To characterize the laser's performance in both continuous-wave and mode-locked regimes.
• To explore wavelength tuning capabilities.

Main Methods:

• Utilized a Yb:SrF2 crystal as the gain medium.
• Employed a spatially single-mode, fiber-coupled laser diode at 976 nm for pumping.
• Implemented a Semiconductor Saturable Absorber Mirror (SESAM) for mode-locking.
• Incorporated a Lyot filter for wavelength tuning.

Main Results:

• Continuous-wave operation yielded up to 704 mW output power with 77.2% slope efficiency.
• Wavelength tuning across 89 nm (1006–1095 nm) was achieved.
• Sub-50 fs soliton pulses as short as 49 fs were generated at 1057 nm.
• Maximum average output power of 313 mW was achieved with 70 fs pulses.

Conclusions:

• The Yb:SrF2 laser is capable of generating ultrashort femtosecond pulses.
• The laser demonstrates efficient diode-pumping and stable mode-locked operation.
• This work highlights the potential of Yb:SrF2 for high-performance ultrafast laser systems.