Diode-pumped mode-locked Yb:Sc₂SiO₅ laser generating 38 fs pulses

Area of Science:

• Laser Physics
• Materials Science

Background:

• Yb3+-doped rare-earth oxyorthosilicate crystals are promising gain media for ultrafast lasers.
• Achieving ultrashort pulse durations requires efficient laser design and mode-locking techniques.

Purpose of the Study:

• To demonstrate sub-40 fs pulse generation from a Yb:Sc2SiO5 laser.
• To investigate the continuous-wave and mode-locked performance of the Yb:Sc2SiO5 laser system.
• To achieve the shortest pulse duration from any Yb3+-doped rare-earth oxyorthosilicate crystal.

Main Methods:

• A Yb:Sc2SiO5 laser was pumped by a fiber-coupled laser diode at 976 nm.
• Continuous-wave (CW) operation was characterized for output power and slope efficiency.
• Mode-locked operation was initiated and stabilized using a SESAM (Semiconductor Saturable Absorber Mirror).

Main Results:

• Maximum CW output power of 545 mW at 1062.6 nm with 64% slope efficiency.
• Continuous wavelength tuning achieved across 80 nm (1030-1110 nm).
• Soliton pulses as short as 38 fs generated at 1069.5 nm with 76 mW average output power.
• Maximum output power of 216 mW achieved for 42 fs pulses, yielding 56.6 kW peak power and 22.7% optical efficiency.

Conclusions:

• The Yb:Sc2SiO5 laser successfully generated ultrashort pulses below 40 fs.
• This work represents the shortest pulses achieved to date for any Yb3+-doped rare-earth oxyorthosilicate crystal laser.
• The results highlight the potential of Yb:Sc2SiO5 as a gain medium for high-performance ultrafast laser systems.