Heterogeneous Packaging of Organic Electro-Optic Modulators With RF Substrates

As organic-based electro-optic (EO) modulators continually improve toward meeting the high performance required by new and developing photonic technologies, the challenge of compact and low loss packaging needs to be addressed.Because organic-based EO modulators and RF circuitry are traditionally built on different substrates homogeneous integration would require developing new designs and fabrication processes. In addition, the organic-based EO modulators most often implement microstrip transmission lines for optimal poling and modulation field overlap meaning the ground plane is encapsulated and unavailable for direct contact. In this letter, a heterogeneous RF packaging scheme featuring a wire bond transition between a ceramic feed coplanar waveguide and a thin-film polymer microstrip is presented. The transition introduces less than 1 dB of RF loss at 50 GHz and was demonstrated on an organic-based EO phase modulator which generated optical sidebands out to 40 GHz.