Hybrid electro-optic polymer/sol-gel waveguide modulators fabricated by all-wet etching process using straight channel and Mach-Zehnder waveguides

摘要

We report hybrid electro-optic (EO) polymer/sol-gel waveguide modulators with a structure for an EO polymer confined laterally in a sol-gel over cladding, which is fabricated by all-wet etching process. The structure enables an adiabatic transition between the sol-gel waveguide and thick EO polymer overlayer. Intensity mode is confined well in 0.9-micron-thick EO polymer overlayer, which reduces a half wave voltage (V_π) due to increased overlap integral in the hybrid EO modulator. Straight channel birefringence EO modulators with the structure reduce the V_π by the factor of 4 after guided wave well confined in the EO polymer. The straight channel waveguide modulator with 2.4-cm-long electrode demonstrated the V_π of 13 V. Preliminary testing results using a Mach-Zehnder waveguide modulator were investigated to reduce the V_π further.