Broadband continuum generation in mode-locked lasers with phase-matched output couplers

Area of Science:

• Laser physics
• Nonlinear optics
• Materials science

Background:

• Few-cycle laser oscillators, such as Ti:sapphire lasers, are crucial for generating ultrashort pulses.
• Achieving broadband spectral enhancement and precise control over laser output is essential for advanced applications.
• Existing methods for spectral broadening often face limitations in efficiency, tunability, or beam quality.

Purpose of the Study:

• To introduce and validate the concept of intracavity phase matching for enhancing laser spectra.
• To demonstrate a broadband phase-matched dielectric output coupler for linear-cavity few-cycle oscillators.
• To explore the tunability of enhanced spectral components and their applicability to various laser systems.

Main Methods:

• Theoretical modeling and experimental demonstration of intracavity phase matching.
• Utilizing a broadband phase-matched dielectric output coupler in a Ti:sapphire laser cavity.
• Employing resonantly enhanced continuum generation to broaden the spectrum.
• Investigating the effect of intracavity dispersion on spectral tunability.

Main Results:

• Achieved spectral enhancement exceeding 10 dB in the matched wavelength range.
• Maintained excellent beam quality during the spectral enhancement process.
• Demonstrated continuous tunability of the enhanced spectral components by adjusting intracavity dispersion.
• Validated the theoretical predictions with experimental results.

Conclusions:

• Intracavity phase matching with broadband dielectric output couplers is an effective method for spectral enhancement in few-cycle lasers.
• The technique offers flexible spectral tailoring capabilities applicable to diverse laser gain media.
• This approach has significant potential for applications including ultrashort pulse generation, seeding high-power lasers, and precision phase measurement.