EUV Laser Oscillator Protection via Beam Delay and Switching

A beam delay line is introduced into the optical path between the oscillator and target material. This delay line temporarily stores the amplified laser beam and releases it after a controlled time delay, ensuring that the oscillator has already completed its pulse generation before the amplified beam interacts with the target and generates back reflections. This preliminary timing action prevents oscillator damage while maintaining high amplifier gain for efficient EUV production.

The beam delay line acts as an intermediary element between the oscillator and the target material interaction zone. It mediates the timing relationship by holding the laser beam in a delayed state, physically separating the oscillator operation from the target interaction in time, thereby protecting the oscillator from backpropagating light while preserving the high gain amplification process.

The beam delay line is designed to serve multiple functions simultaneously: it provides temporal separation to protect the oscillator, maintains beam quality through the delay period, and integrates into the existing amplifier optical path without requiring separate protection systems. This multi-functionality reduces overall system complexity despite adding the delay line component.

The beam delay line maintains the laser beam in a continuous, controlled state during the delay period, ensuring uninterrupted beam quality and timing precision. This continuous useful action eliminates the need for additional shutters or switching mechanisms that would interrupt the beam, thereby reducing system complexity while achieving oscillator protection.