0.24  TW ultrabroadband, CEP-stable multipass Ti:Sa amplifier

Area of Science:

• Physics
• Laser Science
• Ultrafast Optics

Background:

• Ti:sapphire lasers are crucial for generating ultrashort laser pulses.
• Achieving high energy, ultrashort pulses with stable carrier-envelope phase (CEP) is challenging.
• Gain-narrowing limits spectral bandwidth in amplifiers.

Purpose of the Study:

• To demonstrate a single-stage, multipass Ti:sapphire amplifier.
• To achieve sub-13 fs pulses with 3.2 mJ energy at 1 kHz.
• To stabilize the carrier-envelope phase (CEP) of the amplified pulses.

Main Methods:

• Utilized a single-stage, multipass Ti:sapphire amplifier architecture.
• Employed Gaussian filters to mitigate gain-narrowing and achieve a broad spectrum.
• Implemented a feed-forward scheme and a 1 kHz f-to-2f interferometer for active CEP stabilization.

Main Results:

• Delivered sub-13 fs pulses with 3.2 mJ energy at a 1 kHz repetition rate.
• Achieved an ultrabroadband flat-top spectrum with a full width at half maximum (FWHM) > 130 nm.
• Demonstrated active CEP stabilization with <150 mrad rms noise.

Conclusions:

• The developed Ti:sapphire amplifier provides high-energy, ultrashort laser pulses with a stabilized CEP.
• The use of Gaussian filters effectively broadens the spectrum and combats gain-narrowing.
• This system is a significant advancement for applications requiring stable, ultrabroadband, high-energy femtosecond pulses.