Enhancing the inscription rate of surface relief gratings with an incoherent assisting light beam

A beam of light that is incoherent to the recording beams and has its polarization orthogonal to the recording beams is shown to assist the recording process of azo-functionalized polymers through the enhancement of trans–cis–trans cycling. Recording with s:s polarization has earlier been shown to result in very small surface modulations. However, with the help of an incoherent assisting beam, it can record a large surface modulation with a diffraction efficiency of 20.7%. The incoherent assisting beam also leads to an acceleration of the grating formation rate for the recording beams with p:p and 45°:45° polarization.