Radiation force of a high-energy laser and its effects on second-harmonic generation

The radiation force of a high-energy laser caused by reflection at the input surface of a mounted KH₂PO₄ (KDP) crystal is studied, along with its effects on the second-harmonic generation (SHG) efficiency of the laser beam. A comprehensive model incorporating principles of momentum transfer, mechanics, and optics is proposed, taking advantage of which, the mechanical stress within the KDP crystal that is caused by the radiation force, and the SHG efficiency that is affected by the stress are successively studied. Moreover, the effects of the intensity of the laser beam on the radiation force, the stress, and the SHG efficiency are determined, respectively. It demonstrates that a high-energy laser beam causes macroscopic radiation force and further contributes negative effects to SHG efficiency.