RESUMEN
We report long period grating (LPG) devices based on a hybrid architecture incorporating photopatternable fluorinated poly(aryl ether ketone) and silica layers for applications in wavelength filtering and power distribution. The grating structure was implemented using a periodic corrugation on a thermally oxidized silica lower cladding layer, a photopatterned fluorinated polymer ridge waveguide, and a similar polymer top cladding. In this design, the corrugated silica layer allows a highly stable grating structure, while the fluorinated polymer offers a low propagation loss and easy processability. Strong rejection bands have been demonstrated in the C+L wavelength band, in good agreement with theoretical calculations. The fabricated LPG devices show a thermal dependence of 1.5 nm/ degrees C. Based on this design, an array of waveguides incorporating LPGs has also been fabricated. Distribution of light at the resonance wavelength across all the channels from a single input has been demonstrated. These results are promising for power distribution in photonic network applications or on-chip sensors.
RESUMEN
We demonstrate experimentally an optical sensor based on a monolithically integrated Mach-Zehnder interferometer comprising a liquid-core waveguide in one of the optical paths. The device is fabricated with a technique for self-forming microchannels in silica-on-silicon using standard photolithography and deposition processes. Refractometry with a resolution of better than 4x10(-6) is demonstrated using the thermo-optic effect of the liquid medium to vary its refractive index. The polarization dependence of the device response is analyzed.
RESUMEN
Low-attenuation waveguides based on the propagation of long-range surface plasmon polaritons (LRSPPs) along thin Au stripes embedded in low absorption perfluorocyclobutane (PFCB) polymer are presented. A new low in propagation loss of <2.0 dB/cm was achieved for a 4 microm wide waveguide by optimizing the cladding material and fabrication process. The coupling efficiency between the LRSPP waveguide and the optical fiber is studied theoretically and experimentally for different widths of Au stripes and various cladding thicknesses. Lower coupling loss is found when the cladding thickness is close to the mode diameter of the butt-coupled fiber. Based on the 2D distribution of SPP modes calculated by a finite-difference mode solver, a symmetric structure of multilayer claddings with different refractive indices is proposed to optimize device insertion loss.
RESUMEN
The fabrication of embedded microchannels monolithically integrated with optical waveguides by plasma-enhanced chemical vapor deposition of doped silica glass is reported. Both waveguide ridges and template ridges for microchannel formation are patterned in a single photolithography step. The microchannels are formed within an overlay of borophosphosilicate glass (BPSG), which also serves as the top cladding layer of the silica waveguides. No top sealing of the channels is required. Surface accessible fluid input ports are formed in a BPSG layer, with no additional steps, by appropriate design of template layers. By tightly controlling the refractive index of the waveguide layer and the microchannel-forming layer, fully integrated structures facilitating optical coupling between solid waveguides and liquids segments in various geometries are demonstrated. Applications in liquid-filled photonic device elements for novel nonlinear optical devices and in optical sensors and on-chip spectroscopy are outlined.
RESUMEN
A series of novel cross-linkable bromo-fluorinated poly(arylene ether ketone)s have been synthesized and used to fabricate photonic devices. The polymers, prepared by polycondensation reactions of decafluorobenzophenone with mixtures of bisphenols in different ratios, exhibit excellent solubility in common organic solvents and can be easily cast into optical-quality thin films by spin coating. The materials are thermally stable with decomposition temperatures (Td, 5% weight loss) over 450 degrees C and have high glass transition temperatures (Tg) in the range of 164 degrees C-178 degrees C. By controlling the bromine content of the polymers, the refractive index can be precisely controlled over a range as wide as 0.07. The material has excellent design flexibility, low optical loss (0.4-0.6 dB/cm at 1550 nm), a low birefringence (2-3 x 10(-3)), and is suitable for use in wavelength sensitive photonic devices based on arrayed waveguide gratings.
