Laser power meter based on the photomechanical effect

We designed, built and characterized a simple, lowcost all-optical absolute laser power meter based on the photomechanical effect. A contact grating was imprinted on a relatively broadband opaque elastomeric layer of PDMS. The incident light to be measured caused linear, reversible dilations in the elastomer that were measured by another incident light field via changes in the location of its diffraction peaks. We present atomic force microscope surface profiles for verification of the surface relief grating and describe some of the theory used to understand the experimental results.