Yb³⁺:CaYAlO₄-based chirped pulse regenerative amplifier.

Area of Science:

• Laser Physics
• Materials Science
• Optics

Background:

• Chirped Pulse Amplification (CPA) is a key technique for generating high-intensity ultrashort laser pulses.
• Yb-doped crystals are widely used gain media in ultrafast lasers due to their broad emission bandwidth.

Purpose of the Study:

• To experimentally investigate the CPA regime in Yb:CaYAlO4 ( ytterbium-doped calcium yttrium aluminum oxide) crystal.
• To evaluate the performance of Yb:CaYAlO4 for CPA with different polarization states (σ- and π-polarization).
• To analyze gain narrowing effects in relation to polarization states.

Main Methods:

• Experimental setup for chirped pulse amplification.
• Utilized a Yb:KYW oscillator (85 fs pulse duration) as a seed source.
• Employed Yb:CaYAlO4 as the gain medium, testing both σ- and π-polarized light.

Main Results:

• Maximum output power of 4.2 W achieved with σ-polarization at a 200 kHz repetition rate and 310 fs pulse duration.
• Demonstrated 215 fs pulses with 3 W output power and 190 fs pulses with 2.3 W output power for π-polarized light.
• Observed and discussed gain narrowing effects influenced by the polarization state within the crystal.

Conclusions:

• Yb:CaYAlO4 is a promising gain medium for chirped pulse amplification.
• Different polarization states in Yb:CaYAlO4 lead to distinct performance characteristics in CPA systems.
• The study provides valuable insights into optimizing Yb:CaYAlO4 for specific ultrafast laser applications.