Low Distortion Thick-Disk Laser Amplifier

The AEOLUS mission has demonstrated the value and difficulty attached to operating a high energy laser in space. Some delay in the launch of ALADIN launch was explained by shortcomings in the thermal lensing control of the amplifier, which lead to damage to some optical components prior to launch. In 2018, CILAS, in France, demonstrated the operation of a 400-mJ amplifier with no thermal lensing liability at 50 Hz (TRP). These properties are valuable for operation in space, where system lifetime is critical.

A GSTP Building Blocks activity wanted to increase the TRL of the individual components of this amplified, particularly the wavefront control.

The activity demonstrated the possibility to double the diode source at almost no cost to the system: only 3% total mass gain, 10% volume gain, no change in efficiency, and no change in output characteristics. This is quite unique to the pumping module designed for CILAS amplifier and could double its effective lifetime.

Concurrently, materials that are space qualified have been identified and tested to replace those used in the first breadboard tested. A stellar wavefront distortion correction (RMS at 0.02l across the beam) was achieved with space compatible technology.