Fabrication of an asymmetric Bragg coupler-based polymeric filter with a single-grating waveguide.

In this work, a first report on fabricating an asymmetric Bragg coupler-based filter on polymeric waveguides without input-waveguide grating was revealed. The fabrication process we developed was using holographic interference techniques, capillary effect, soft lithography, and micro molding process. The transmission dip of about -9.2 dB and the 3 dB transmission bandwidth of about 0.125 nm were obtained from a filter.

Fabrication of optical filters based on polymer asymmetric Bragg couplers.

In this work, we successfully developed a process to fabricate dual-channel polymeric waveguide filters based on an asymmetric Bragg coupler (ABC) using holographic interference techniques, soft lithography, and micro molding. At the cross- and self-reflection Bragg wavelengths, the transmission dips of approximately -16.4 and -11.5 dB relative to the 3 dB background insertion loss and the 3 dB transmission bandwidths of approximately 0.6 and 0.5 nm were obtained from an ABC-based filter. The transmission spectrum overlaps when the effective index difference between two single waveguides is less than 0.002.

Fabrication of high-resolution periodical structure on polymer waveguides using a replication process.

This paper describes a procedure to replicate a polymeric wavelength filter. In this work, the grating structure on a polymer is fabricated first using holographic interferometry and micro-molding processes. The polymeric wavelength filters are produced by a two-step molding process where the master mold is first formed on a negative tone photoresist and subsequently transferred to a PDMS mold; following this step, the PDMS silicon rubber mold was used as a stamp to transfer the pattern of the polymeric wavelength filters onto a UV cure epoxy. Initial results show good pattern transfer in physical shape. At the Bragg wavelength, a transmission dip of -15.5 dB relative to the -3dB background insertion loss and a 3-dB-transmission bandwidth of ?6nm were obtained from the device.

Fabrication of polymer waveguides by a replication method.

We have developed a soft-lithography method to replicate polymer waveguides. In this method, the waveguides are produced by a two-step molding process where a master mold is first formed on a negative-tone photoresist and subsequently transferred to a polydimethylsiloxane (PDMS) mold; a PDMS silicone rubber mold is then used as a stamp to transfer the final waveguide pattern onto an UV cure epoxy. Initial results show good pattern transferring in physical shape. The optical performance is measured based on the propagation loss. In our design, the loss was measured at 0.28 dB/cm for 1.3 microm and 0.26 dB/cm for 1.55 microm.

Transducing mechanical force by use of a diffraction grating sensor.

A novel means of transducing mechanical force by using a polymeric-based diffractive grating sensor is presented. The diffraction gratings are successfully fabricated upon poly(dimethyl siloxane) polymer substrates by holographic interference and micromolding. A micromaterial tensile test incorporated into the surface diffraction grating experiment showed that a relationship between the load and the observed diffraction-pattern shift could be obtained. The results show an excellent correlation between the optical measurement and load, with a sensitivity of 0.05 N.

Fabrication of a high-resolution periodical structure using a replication process.

We describe a procedure for rapidly and conveniently prototyping a periodic structure at submicrometer order using holographic interferometry and micro-molding processes. In this experiment, the master of the periodic structure was created on an i-line submicrometer positive photoresist film by a holographic interference using a He-Cd (325nm) laser. A subsequent mold using polydimethylsiloxane (PDMS) polymer was cast against this master and used as a stamp to transfer the grating pattern onto a UV cure epoxy. The technique shows accurate control for the transferring of a grating's period and depth. The grating pattern on the epoxy produced by the PDMS mold shows an average of less than 2% error in the grating period and an average of 15% error in depth reproduction.