Boron nitride plasma micro lens for high intensity laser pre-pulse suppression

Area of Science:

• Laser Physics
• Plasma Physics
• Materials Science

Background:

• High power lasers often suffer from amplified spontaneous emission (ASE) and pre-pulses.
• These low-intensity components reduce the overall quality and effectiveness of the main laser pulse.
• Improving the contrast ratio between the main pulse and pre-pulses is crucial for many laser applications.

Purpose of the Study:

• To investigate the suppression of amplified spontaneous emission (ASE) and pre-pulses in high power lasers.
• To demonstrate the efficacy of a boron nitride plasma microlens for enhancing laser pulse contrast.
• To maintain high transmittance of the main pulse energy during the suppression process.

Main Methods:

• A boron nitride (BN) disk with a central hole was ablated using an Nd:YAG laser to create a plasma microlens.
• High power laser pulses were propagated through the generated boron nitride plasma microlens.
• The focal lengths of the plasma lens for the main pulse and pre-pulse were analyzed.

Main Results:

• The boron nitride plasma microlens effectively suppressed amplified spontaneous emission (ASE) and pre-pulses.
• A significant increase in the main pulse/pre-pulse contrast ratio, by one order of magnitude, was achieved.
• High transmittance of the main pulse energy was maintained through the plasma microlens.

Conclusions:

• Boron nitride plasma microlenses offer a viable method for improving high power laser pulse quality.
• This technique enhances laser contrast by effectively separating and mitigating low-intensity components.
• The method is efficient, maintaining high energy transmittance for practical laser system applications.