Electrohydrodynamics pump and machine learning enable portable high-performance excimer laser

According to a recent study published in APL PhotonicsA research team led by Professor Liang Xu of the Hefei Institutes of Physical Sciences of the Chinese Academy of Sciences has developed an ultra-compact excimer laser the size of a thermos bottle.

Excimer lasers are critical sources of deep ultraviolet light and are widely used in scientific research, industrial processing and environmental monitoring. However, traditional systems rely on mechanical fuel pumps for fluid circulation, resulting in large size, high noise levels and significant vibration. These limitations limit their application in field environments, marine exploration, and airborne platforms.

To solve these problems, the researchers replaced the mechanical pumps with a multi-needle corona discharge electrohydrodynamic (EHD) pump. This eliminated the need for moving parts and reduced the system volume to Ø130 mm × 300 mm. Using a self-developed, non-invasive Schlieren point velocimetry technique, the researchers measured a gas flow velocity of 1.27 m/s inside the laser cavity.

Operating at 100 Hz, the system achieved a gas refresh rate of 6.35, delivering pulse energies in excess of 2 mJ while maintaining exceptional energy stability, with a relative standard deviation as low as 1%.

The researchers also observed unique explosive transition behavior in the laser’s pulse energy under certain conditions. Through complex analysis of the photochemical reactions of the XeCl excimer array, they discovered that this phenomenon is linked to a threshold-triggered burst of photon flux, revealing the microscopic mechanism behind the changes in the macroscopic performance of the laser.

Additionally, the team developed an interpretable machine learning model capable of predicting energy transitions over a wide range of operating parameters.

This study provides valuable support for the optimization and control of ultra-compact excimer laser systems in practical applications.