Octave-spanning frequency comb from a single-diode-pumped 1 GHz Ti:sapphire laser

Area of Science:

• Photonics and Optical Engineering
• Laser Physics and Technology

Background:

• Broadband frequency combs with GHz mode spacings are crucial for optical metrology and astrophotonics.
• Achieving required pulse energies for supercontinuum generation at 1 GHz repetition rates often demands high average powers, limiting accessibility with simple ultrafast lasers.

Purpose of the Study:

• To demonstrate octave-spanning comb generation using dispersion-engineered silicon nitride waveguides.
• To achieve this using a low-power, single-diode-pumped Ti:sapphire laser system.
• To present carrier-envelope-offset control and stabilization for the generated comb.

Main Methods:

• Utilized dispersion-engineered silicon nitride (Si3N4) waveguides.
• Employed a three-element, 1 GHz Ti:sapphire laser, diode-pumped, as the pump source.
• Implemented carrier-envelope-offset control and stabilization techniques.

Main Results:

• Achieved octave-spanning comb generation from 539 to 1078 nm (-20 dB bandwidth).
• Demonstrated laser repetition-rate stability of 790 mHz over a 1-hour period.
• Successfully stabilized the carrier-envelope offset to a continuous-wave laser.

Conclusions:

• The developed system provides a straightforward method for generating a coherent, broadband supercontinuum.
• This technology spans the visible to near-infrared spectrum.
• It holds significant potential for applications in optical frequency metrology, quantum timekeeping, and astrophysical spectrograph calibration.