Diffraction from a tunable elastomeric grating with a refracting fluid layer
We replicate a diffraction grating by soft lithography. Tunable diffraction is accomplished by modifying the grating groove density through the application of mechanical strain on the elastomeric grating replica. The strain-variable diffraction output is extended by adding a refracting liquid layer to the grating. Experimental results are accurately described by the combined effects of diffraction by a deformable grating and refraction by a fluid with a curved surface.