Radiation hard mode-locked laser suitable as a spaceborne frequency comb.

Area of Science:

• Physics
• Materials Science
• Laser Technology

Background:

• Diode-pumped solid-state lasers (DPSSLs) are crucial for various applications, including frequency comb generation.
• Assessing the radiation tolerance of DPSSLs is essential for their deployment in space missions.
• The Ytterbium-doped Potassium Yttrium Tungstate (Yb:KYW) crystal is a promising gain medium for DPSSLs.

Purpose of the Study:

• To evaluate the radiation hardness of a passively mode-locked Yb:KYW DPSSL.
• To determine the impact of gamma and proton radiation on laser performance and stability.
• To assess the suitability of this DPSSL technology for long-duration space missions.

Main Methods:

• The passively mode-locked DPSSL utilized an Yb:KYW gain medium.
• The laser system was subjected to ground-level gamma radiation up to 170 krad(H2O) over 5 days.
• Proton radiation exposure was conducted with a fluence of 9.76·10^10 cm^-2 within minutes.

Main Results:

• Gamma irradiation caused minor performance changes, maintaining the solitonic regime, with full recovery within weeks.
• Proton irradiation at a high fluence showed no discernible alteration in laser performance.
• The laser demonstrated excellent noise properties and complete stabilization post-irradiation.

Conclusions:

• The femtosecond DPSSL technology investigated exhibits significant radiation hardness.
• This DPSSL is a viable candidate for generating frequency combs for extended space missions.
• The Yb:KYW DPSSL demonstrates robust performance under simulated space radiation environments.