Fluid-enhanced tunable diffraction with an elastomeric grating

• Main Authors: Pada, Caironesa T, Guerrero, Raphael A
• Format: text
• Published: Archīum Ateneo 2017
• Subjects: Diffraction gratings; Diffraction; Liquids; Water. Refraction; Refractive index; Lithography; Microfluidics; Atomic force microscopy; Optical engineering; Optics; Physics
• Online Access: https://archium.ateneo.edu/physics-faculty-pubs/4; https://www.spiedigitallibrary.org/journals/Optical-Engineering/volume-56/issue-5/054101/Fluid-enhanced-tunable-diffraction-with-an-elastomeric-grating/10.1117/1.OE.56.5.054101.short
• Institution: Ateneo De Manila University

We replicate a diffraction grating by soft lithography. Tunable diffraction is accomplished by modifying groove spacing through the application of strain on the elastomeric replica. The range of strain-variable diffraction angles is extended by adding a refracting liquid layer to the grating. Using a water layer, the diffraction angle is tuned from 38 to 33.4 deg with an applied strain of 17.7%. With an equal amount of strain, employing a glycerol layer results in the diffraction angle varying from 38.8 to 34.4 deg. Our experimental results are accurately described by the combined effects of diffraction by a deformable grating and refraction by a fluid with a curved surface.