Photon Trap

Photon Trap

Photon Trap confines photons between two high-reflectance mirrors for amplifying the CW circulating laser power by orders of magnitude.

The applications of Photon Trap are:

  • Laser Propulsion
  • Optomechanical Research using High Power CW Lasers
  • High Power CW Laser Power Calibration
  • CW Optics Damage Threshold Measurement
  • Beam Propagation Characterization for Test and Evaluation (T&E) of CW High Energy Lasers


Photon Trap demonstrated to produce a CW 540-kW intracavity laser power with 1-kW pumping.

Photon Trap Demonstration

Total CW radiation pressure over the entire mirror in the Photon Trap as a function of  the CW intracavity laser power

The radiation pressure was measured with a radiation power meter that is essentially a horizontally operating digital scale.  The intracavity laser power was measured optically by monitoring the leakage laser power through the end mirror with a known transmission coefficient.

Demonstration of Dielectric Mirror Damage Threshold Measurement

A damaged high power dielectric mirror during the CW laser damage threshold measurement

  • Mirror reflectance: >0.999
  • Mirror diameter: 2.5 cm
  • Intracavity laser beam power at the damage threshold:  260 kW
  • Intracavity laser beam diameter: 0.6 cm
  • Measured CW damage threshold: 920 ± 80 kW/cm2