Fabrication of large-core, high-Δ optical waveguides in polymers

Flexible polymeric rib waveguide with self-align couplers system

The authors report a polymeric based rib waveguide with U shape self-align fiber couplers system using a simple micromolding process with SU8 as a molding material and polydimethysiloxane as a waveguide material. The material is used for its good optical transparency, low surface tension, biocompatibility, and durability. Furthermore, the material is highly formable. This unique fabrication molding technique provides a means of keeping the material and manufacturing costs to a minimum. The self-align fiber couplers system also proves a fast and simple means of light coupling. The flexible nature of the waveguide material makes this process ideal for a potential wearable optical sensor.

Single-mode optical waveguides fabricated from fluorinated polyimides

Buried channel optical waveguides were fabricated from fluorinated polyimides. They operated in single mode and showed an optical loss of less than 0.3 and 0.7 dB/cm for TE and TM polarizations, respectively, at a wavelength of 1.3 mum. Moreover, these waveguides had high heat and moisture resistance; the optical loss did not significantly change after heating at 380 degrees C for 1 h or after exposure to 85% relative humidity at 85 degrees C for over 200 h.

Simultaneous fabrication of optical channel waveguides and out-of-plane branching mirrors from a polymeric slab structure

Recently, polymeric multimode optical waveguides have been widely studied for low-cost interconnection use. We describe fabrication processes for a low-loss poly(methyl methacrylate) (less than 0.1 dB/cm at 675 nm) waveguide based on the reactive-ion-etching technique and for a slope (45 degrees mirror face) formed on the waveguide. To obtain a ridge core with a crack-free and extremely smooth surface, we applied a heating process at a temperature greater than the glass transition point and a smoothening process by solvent. Furthermore, to fabricate simultaneously both vertical and sloped sidewalls, we applied a unique phenomenon in the process that decreases the etching rate directly under a narrow opening of etching mask. By using the above fabrication techniques, we demonstrated an out-of-plane branching mirror.