  Electromagnetic (EM) wave detection over a large spectrum has recently
attracted significant amount of attention. Traditional electronic EM wave
sensors use large metallic probes which distort the field to be measured and
also have strict limitations on the detectable RF bandwidth. To address these
problems, integrated photonic EM wave sensors have been developed to provide
high sensitivity and broad bandwidth. Previously we demonstrated a compact,
broadband, and sensitive integrated photonic EM wave sensor, consisting of an
organic electro-optic (EO) polymer refilled silicon slot photonic crystal
waveguide (PCW) modulator integrated with a gold bowtie antenna, to detect the
X band of the electromagnetic spectrum. However, due to the relative large RC
constant of the silicon PCW, such EM wave sensors can only work up to tens of
GHz. In this work, we present a detailed design and discussion of a new
generation of EM wave sensors based on EO polymer refilled plasmonic slot
waveguides in conjunction with bowtie antennas to cover a wider electromagnetic
spectrum from 1 GHz up to 10THz, including the range of microwave, millimeter
wave and even terahertz waves. This antenna-coupled plasmonic-organic hybrid
(POH) structure is designed to provide an ultra-small RC constant, a large
overlap between plasmonic mode and RF field, and strong electric field
enhancement, as well as negligible field perturbation. A taper is designed to
bridge silicon strip waveguide to plasmonic slot waveguide. Simulation results
show that our device can have an EM wave sensing ability up to 10 THz. To the
best of our knowledge, this is the first POH device for photonic terahertz wave
detection.
