Integrated-Photonic Electromagnetic Signal Detector

NASA’s ESD is a small form-factor electromagnetic signal detector fabricated on a photonic crystal substrate (e.g., silicon-on-insulator wafer, III-V platform). It integrates a (1) miniature on-chip antenna (e.g., microstrip antenna) aligned to the desired operational frequency, (2) 2-D photonic crystal, and (3) electro-optic polymer (located on the photonic crystal). At the heart of the detector is the 2D photonic crystal. Using an array of carefully sized pores or “nano-cavities,” a waveguide is formed that governs the crystal’s optical transmission properties. An electro-optic polymer (a material that shifts its refractive index in response to external electric fields) is used to coat the photonic crystal. The combination of the 2D photonic crystal and EO polymer make up the resonator. A compact antenna with separate active feed and ground regions is placed near the photonic crystal, creating a gap through which the electromagnetic signal couples to the photonic crystal structure. Under normal conditions (no external signal), the EO polymer’s refractive index remains unchanged, producing a stable resonant notch in the device’s optical transmission. When the antenna intercepts an electromagnetic wave, the resulting electric field modifies the EO polymer’s refractive index, causing a measurable shift in the resonator’s optical output. By monitoring this shift, a photodetector can accurately determine the presence and magnitude of the incoming electromagnetic wave. NASA’s low SWaP-C, high precision ESD can be adapted for use in a variety of systems including remote sensing instruments (e.g., radiometers, spectrometers), transceivers for 5G communications networks, and other electromagnetic signal detection applications. The invention is available for patent licensing. In remote sensing and communication systems, designers constantly face the challenge of maintaining high detection sensitivity while minimizing Size, Weight, Power consumption, and Cost (SWaP-C). Small satellites and portable communication devices, for instance, have strict size and power constraints yet require accurate detection of electromagnetic signals across microwave to millimeter-wave frequencies. Although electronics-based receivers can provide excellent performance, their components tend to increase both power consumption and overall device footprint. Developed at NASA’s Goddard Space Flight Center, the Integrated-Photonic Electromagnetic Signal Detector (ESD) addresses these challenges by integrating photonic crystal technology with an electro-optic (EO) polymer and a compact antenna structure to achieve miniaturization without sacrificing precision. Furthermore, by converting an incoming electromagnetic signal into an optical domain response, the device significantly reduces reliance on traditional electronics. Thus, this NASA innovation is a promising solution for high-performance sensing or communications applications where minimized SWaP-C is essential.