Vacuum-tuned graded-index polymer waveguides on silicon substrates

A new method for producing graded-index (GRIN) profiles on type A photolime gel-based polymer waveguides with vacuum drying is demonstrated. Vacuum drying allows optical waveguides to be built on substrates with a higher index of refraction without intermediate lower-index cladding layers while keeping the concentration of various dopants unperturbed. The waveguide-loss and GRIN profiles were compared for vacuum-dried and alcohol-dried samples. Waveguide losses from 0.1 to 10 dB/cm were observed.