Efficient Nd:YAG Laser Frequency Doubling with Periodically Poled KTP.

Area of Science:

• Nonlinear optics
• Laser technology
• Materials science

Background:

• Potassium titanyl phosphate (KTP) is a key material for nonlinear optical frequency conversion.
• Conventional KTP crystals often face limitations in efficiency and optical damage threshold.
• Periodically poled KTP offers potential for enhanced performance in laser applications.

Purpose of the Study:

• To investigate the efficiency and performance of periodically poled flux-grown KTP for extracavity frequency doubling.
• To compare the performance of periodically poled KTP with conventional type II phase-matched KTP.
• To assess the optical damage susceptibility of periodically poled KTP.

Main Methods:

• Utilizing periodically poled flux-grown KTP for extracavity frequency doubling of a 1064-nm Nd:YAG laser.
• Employing both Q-switched and mode-locked operation for laser frequency doubling experiments.
• Measuring conversion efficiency and average output power.

Main Results:

• Achieved a conversion efficiency exceeding 65% in Q-switched operation.
• Generated 1.34 W of average frequency-doubled power from 2.2 W of mode-locked laser output.
• Observed approximately two times higher conversion efficiency compared to conventional type II phase-matched KTP.
• Found periodically poled KTP to be less susceptible to optical damage than type II KTP.

Conclusions:

• Periodically poled flux-grown KTP is highly effective for efficient Nd:YAG laser frequency doubling.
• Periodically poled KTP offers significant advantages in conversion efficiency and optical robustness over conventional KTP.
• This material presents a promising solution for high-power laser frequency conversion applications.