Heterogeneous Integration of MEMS and GHz Electro-Optic Polymer Modulators for RF Communications

Heterogeneous integration of microelectromechanical systems (MEMS) with polymer based electro-optic (EO) modulators is proposed, to produce compact and deployable modulators for RF photonics applications. Current technology allows fabrication of compactand light-weight modulators, but these interferometric devices are still not truly deployable, because they require control and feedback electronics for balancing and stabilization. EO polymer technology capable of producing 100GHz, sub-one-voltmodulators will be combined with MEMS technology that provides high Q resonators and filters that operate in the KHz-MHz frequencies. The approach is to mechanically balance an EO modulator using a MEMS resonant structure, and integrate balancingcircuitry (which includes high Q MEMS band-pass filters) by either integrating on the same substrate or via flip-chip bonding, contained in the same modulator package. DC biasing and RF modulation are separated, eliminating the need for wide-band biasingcomponents, and avoiding bias drift problems that are common in electrical biasing. This work builds on the success of the Phase I effort, where mechanical biasing and heterogeneous integration are experimentally demonstrated. Successful completion ofthis work will allow 2 to 3 orders of magnitude reduction in size, mass and power consumption over current methods, and will enable low cost fabrication of high-frequency modulators.