Electron beam direct write polymeric optical waveguide filters

Waveguide wavelength filter with a first order Bragg diffraction grating was demonstrated in ENR polymer. Electron beam sensitive ENR exhibits many unique properties, and both the waveguide and the gratings were fabricated using a single exposure of electron beam. This technique eliminates alignment problems as well as possible fabrication errors,because fewer processing steps are involved. First order Bragg reflection around 1550 nm wavelength was obtained, and a transmission peak of -27 dB (>99% reflection) was obtained with a 5 mm grating length. The 3 dB transmission bandwidth was ∼0.8 nm and the 10 dB bandwidth was ∼1.0 nm. Both the electron beam dosage and the waveguide dimension can be used to fine tune the Bragg wavelength, making the electron beam direct write process suitable for the fabrication of closely spaced narrow band filters for dense WDM systems.