Organic electro-optic materials offer exceptional processability (both from solution and the gas phase) that permit fabrication of flexible and conformal device structures and the integration of organic materials with a wide range of disparate materials. In addition, organic electro-optical materials have fundamental response times that are in the terahertz region, and useable electro-optic coefficients that are approaching 300 pm/V (at telecommunication wavelengths). In addition to fabrication by traditional lithographic methods, multiple devices on a single wafer have been fabricated by soft and nano-imprint lithography. In this presentation, we review the fabrication and performance evaluation of a number of all-organic and organic-silicon photonic ring microresonator devices. Both electrical and thermal tuning of devices, including both single and multiple ring micro-resonators, are demonstrated.
We have developed a novel approach for fabricating and testing optical ring resonators. Using a side-polished optical fiber and fabricating a ring waveguide directly over its core, an efficient and passive signal filter in the 1.55 um telecommunication band is created. A standard single mode optical fiber is permanently secured in an arcing groove in quartz and is side polished proximally to its core. The ring resonator is fabricated using two-photon initiated free-radical polymerization of tri-functional acrylate on low-index quartz substrate with a 100 femtosecond pulsed Ti/sapphire laser. The quartz substrate is inverted and vacuum mounted to an X-Y-Z stage so that the polymer ring waveguide can be positioned directly above the core of the fiber forming a vertically coupled ring resonator. Our technique allows infinite variation of the width, height, diameter and location (therefore the coupling strength between the fiber and the ring) of the ring resonator waveguide. This approach enables resonators to be fabricated, tested and subsequently removed multiple times on the same side-polished fiber, refining both the ring resonator geometry and materials. Because it is a fiber-based device, it possesses negligibly low optical insertion loss and can be used for fixed and tunable wavelength filters, intensity modulators, and fiber-optic sensors. Both theoretical analysis and experimental data will be presented.
Future generations of photonic devices which incorporate poled organic nonlinear optical materials may be aided by, or require the use of non-traditional electrodes. This report details the integration of highly doped silicon as one of the poling/modulating electrodes in the simple reflection type experiment for determination of nonlinear optical activity in a guest-host polymer system. The measurements illustrate that the behavior of doped-silicon and the traditional indium tin oxide (ITO) electrodes are analogous. A number of organic chromophore guests were investigated as well as multiple polymer hosts. Results demonstrate both successful poling and subsequent modulation of NLO materials, including the calculation of r33 values comparable to those achieved using a standard ITO electrode.