Why can pulsed lasers produce extremely high peak power?

Pulsed lasers achieve extremely high peak power by concentrating their total output energy into very brief bursts of light. Because power is defined as the rate at which energy is delivered, compressing that energy into an incredibly short time interval—sometimes as brief as femtoseconds—results in an immense instantaneous power output.1

Historically, amplifying these short pulses was limited because the high intensity would damage the laser's internal components. To overcome this, physicists Gérard Mourou and Donna Strickland developed chirped pulse amplification (CPA). This technique involves:2

• Stretching: The pulse is temporally stretched, which reduces its peak power to a safe level for amplification.2
• Amplification: The lower-intensity, stretched pulse is then safely amplified to a much higher energy level.2
• Compression: Finally, the pulse is compressed back into a short duration, resulting in a beam with extremely high peak power that would have otherwise destroyed the instrument.2