Phase stabilization of an octave-spanning Ti:sapphire laser

Area of Science:

• Laser Physics
• Ultrafast Optics
• Nonlinear Optics

Background:

• Carrier-envelope phase (CEP) stabilization is critical for precision measurements and nonlinear optics.
• Ti:sapphire lasers are workhorses for ultrafast science, often requiring octave-spanning bandwidths.
• Traditional CEP stabilization methods can be complex and may not suit all laser geometries.

Purpose of the Study:

• To demonstrate direct carrier-envelope phase stabilization in a standard x-folded, octave-spanning Ti:sapphire laser.
• To quantify the achieved CEP error over a broad frequency range.
• To characterize the intracavity continuum generation responsible for the laser's broad bandwidth.

Main Methods:

• Implementation of a direct CEP stabilization technique within an x-folded Ti:sapphire laser cavity.
• Measurement of the in-loop accumulated carrier-envelope phase error.
• Characterization of intracavity continuum generation using beam parameter measurements.

Main Results:

• Successful direct stabilization of the carrier-envelope phase was achieved.
• The in-loop accumulated CEP error was measured to be 0.175 radians across a bandwidth from 1.65 mHz to 102 kHz.
• Intracavity continuum generation was characterized, confirming its role in achieving octave bandwidth.

Conclusions:

• Direct CEP stabilization is feasible in standard x-folded, octave-spanning Ti:sapphire lasers.
• The achieved low phase error demonstrates the effectiveness of the stabilization method.
• This work provides a robust approach for CEP stabilization in widely used ultrafast laser systems.