title: UV trimming of polarization-independent microring resonator by internal stress and temperature control.
abstract: The temperature dependence of the resonant wavelength of vertically coupled microring resonator can be controlled via internal stress caused by the thermo-optic and photo-elastic effects. In the case of strong internal stress, a polarization-independent microring resonator can be realized by controlling the device surface temperature using a heater module; the temperature dependence of TE and TM polarizations are different due to the internal stress and thus manipulating temperatures, the resonant wavelengths for TE and TM can be equalized at a specific temperature. In this study, the UV trimming of polarization-independent wavelength was demonstrated using UV-sensitive SiON as a core material. The temperature dependence of TE polarization was almost athermalized and that of TM was made negative by controlling internal stress. As a result, the simultaneous realization of the UV trimming and the polarization-independent microring was made possible more easily than before; the UV trimming can be done at room temperature due to the athermalized resonant wavelength for TE polarization.
authors.affiliation: Department of Electrical and Computer Engineering, Graduate School of Engineering, Yokohama National University, Yokohama, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Sato
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kokubun
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008420:Manufactured Materials / Q000528:radiation effects; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D013314:Stress, Mechanical; D013696:Temperature; D014159:Transducers; D014466:Ultraviolet Rays