Yb3+-doped YVO4 crystal for efficient Kerr-lens mode locking in solid-state lasers

Area of Science:

• Laser Physics
• Materials Science
• Ultrafast Optics

Background:

• Diode-pumped solid-state lasers are crucial for various applications.
• Achieving ultrashort pulses from ytterbium (Yb)-doped crystalline lasers is an ongoing research area.
• Kerr-lens mode locking (KLM) is a key technique for generating femtosecond pulses.

Purpose of the Study:

• To demonstrate soft-aperture Kerr-lens mode locking (KLM) in a diode-pumped femtosecond Yb3+:YVO4 laser.
• To generate and characterize ultrashort laser pulses from this novel laser system.
• To measure the nonlinear refractive indices of the Yb3+:YVO4 crystal.

Main Methods:

• Utilized a diode-pumped Yb3+:YVO4 laser.
• Implemented soft-aperture Kerr-lens mode locking (KLM) for pulse generation.
• Measured pulse duration, center wavelength, output power, pulse repetition frequency, and nonlinear refractive indices.

Main Results:

• Achieved near-transform-limited pulses as short as 61 femtoseconds (fs).
• Generated pulses centered at 1050 nm with 54 mW output power and 104.5 MHz repetition frequency.
• Observed a mode-locking threshold at 190 mW absorbed pump power and measured nonlinear refractive indices of Yb3+:YVO4.

Conclusions:

• This study reports the first demonstration of soft-aperture Kerr-lens mode locking in a diode-pumped femtosecond Yb3+:YVO4 laser.
• The generated 61 fs pulses are the shortest reported directly from an Yb laser with a crystalline host.
• The results highlight the potential of Yb3+:YVO4 as a gain medium for high-performance ultrafast lasers.