Source: Laboratory for Laser Energetics – University of Rochester

Chirped-Pulse Amplification in Ultrafast Laser Systems

Introduction

Chirped-pulse amplification (CPA) is a technique used in ultrafast laser systems to prevent detrimental nonlinear effects that can occur in amplifiers for ultrashort optical pulses. This method involves stretching the pulse duration before amplification and compressing it back afterwards, effectively reducing the peak power to safe levels.

Evolution of Peak Powers

CPA has enabled the development of table-top amplifiers capable of producing pulses with millijoule energies and femtosecond durations, resulting in peak powers reaching several terawatts. In larger facilities, peak powers in the petawatt range have been achieved.

Applications in Ultrashort Pulses

For the highest peak powers, multiple amplifier stages based on titanium–sapphire crystals are used, particularly for applications like high harmonic generation. Fiber-based CPA systems are also utilized, offering high average powers of tens to over 100 watts.

Optical Parametric Chirped-Pulse Amplification

CPA is not limited to solid-state amplifiers but can also be applied to optical parametric amplifiers, leading to optical parametric chirped-pulse amplification (OPCPA). This technique further expands the capabilities of ultrafast laser systems.

Recent Recognition

In 2018, the Nobel Prize in Physics was awarded to Gérard Mourou and Donna Strickland for their pioneering work on chirped-pulse amplification, highlighting its significance in advancing laser technology and enabling the generation of high optical intensities.

Future Developments

Research continues on improving CPA systems, exploring new components like volume Bragg gratings for high pulse energies and coherent beam combining for even greater power outputs. The versatility of CPA in different types of amplifiers opens up possibilities for diverse applications in ultrafast optics.

Source: MDPI
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