| dc.description.abstract | This thesis discusses the measurement and fabrication process utilizing the negative photoresist SU-8 as an optical waveguide micro-ring resonator. Since the resonator can filter light of a specific wavelength, a high-order optical filter can be manufactured by using multiple micro-ring resonators. The optical resonator has the advantages of small size, low loss, and integration of optical systems. In addition, since the resonant wavelength can be changed by changing the resonator dimension, the resonator offers tunability for integrated photonics. This feature can be also used to make mechanical, biological, and chemical sensors. By utilizing the SU8 waveguide, there are a few potentials for integrated photonics. First, it provides a reconfigurable way to measure and to optimize the fabrication process of the optical waveguides. We discuss the fabrication process, waveguide loss, and quality factor of the micro resonators, providing the general waveguide parameters for the future reconfigurable design. Second, this study helps to build a reconfigurable in-line monitor platform for on-chip micro resonator (modulator). By fabricating a reconfigurable drop port and measuring the loss and quality factor of micro-ring resonators made of other materials (E.g. Silicon / silicon nitride), the SU8 waveguide can help to minimize the loaded effect on the micro resonator by later removing the drop port after the measurement. Last, the reconfigurable SU-8 waveguide provides the potential for on-chip interferometer by designing the proper resonator radius and the corresponding free-spectral range (FSR). In the thesis, we include the fabrication optimization of SU-8 waveguide, optical measurement, and preliminary results for a reconfigurable waveguide. In the experiments, two different photoresists of SU-8 2000.5 and SU-8 GM1040 are used for comparison. These photoresists provide different coating thicknesses, which strongly affect the waveguide behavior. Also, the simulation analysis of the propagated mode-profile will be discussed in the second chapter, by comparing the loss under different thicknesses of the SU-8 and of the buried oxide layer. In experiments, we will show the optical loss of the SU8 waveguide under different waveguide dimensions. Conventional UV optical lithography is used for waveguide fabrication, which provides better through-put for mass, rapid, and economic production for future usage. We use contact exposure method for UV patterning. By changing the exposure time, we observe the difference between the waveguide width and gap on the mask and the fabricated one after development. For optical measurement, we discuss the optical coupling, loss, and transmission resonance in the transverse electric mode (TE mode). By designing ring radius 100μm a free spectral range (FSR) of ~2.24nm is obtained corresponding to 280 GHz in frequency. We identify that lower optical loss can be achieved by either increasing the thickness of SU-8, or the thickness the buried oxide layer. The transmitted light is coupled into the waveguide and the corresponding transmission spectrum is measured in C-band. Resonance with Q up to 991 can be identified while the repetition rate (or FSR) is matched with our designed resonators. In the future study, this reconfigurable waveguide can be used in replacement of the regular drop-port waveguide, in which strongly degrades the quality factor in the resonator, or can be used as on-chip interferometry for optical frequency metrology. | en_US |