Design and fabrication of a planar PDMS transmission grating microspectrometer

We describe the monolithic integration of microfluidic channels, optical waveguides, a collimating lens and a curved focusing transmission grating in a single PDMS-based microsystem. All optical and fluidic components of the device were simultaneously formed in a single layer of high refractive index (n 3c1.43) PDMS by soft lithography. Outer layers of lower-index (n 3c1.41) PDMS were subsequently added to provide optical and fluidic confinement. Here, we focus on the design and characterization of the microspectrometer part, which employs a novel self-focusing strategy based on cylindrical facets, and exhibits resolution <10 nm in the visible wavelength range. The dispersive behavior of the grating was analyzed both experimentally and using numerical simulations, and the results are in good agreement with simplified analytical predictions. \ua9 2013 Optical Society of America.Peer reviewed: YesNRC publication: Ye