Millimeter-wave Modulators for Sparse Imagers

In this Phase II STTR effort PSI will team with University of Delaware to develop advanced electro-optic (EO) sensing module that are capable of efficiently up-converting millimeter-wave (mmW) signal into optical sidebands for low-cost passive mmW imaging applications. Conversion efficiency of the modulators will be significantly enhanced by leveraging thin-film Lithium niobate on insulator (TFLNOI) technologies. Advanced device designs, such as RF and optical resonators, offer further field enhancement and longer interaction length in addition to tighter mode confinement in both optical and RF domains in hybrid Si3N4-TFLN platform. Various devices and components, i.e., phase and Mach-Zehnder-interferometer (MZM) modulators, optical racetrack-resonator enhanced modulators, RF-resonator enhanced modulators, ultra-high numerical aperture fiber (UHNA) coupler, compact U-bend, will be designed, optimized, fabricated, characterized, and packaged for mmW modulation. The developed modulators will be integrated into optical-based sensing modules, providing a building block into on-going development of low-cost passive mmW imager. Significant improvement in modulation efficiency reduces gain requirement in the RF frontend, thereby significantly simplifying the mmW sensing node development. Characterization will be performed to evaluate the modulator conversion efficiency and detection sensitivity. An array of the sensor nodes will be integrated into a distributed aperture to validate the performance of EO modulators.