Advanced imaging capabilities by incorporating plasmonics and metamaterials in detectors

Abstract

Ultraviolet detection is often required to be made in the presence of a strong background of solar radiation which needs to be suppressed, but materials limitations at these wavelengths can impact both filter and sensor performance. In this work, we explore the use of 1D photonic bandgap structures integrated directly onto a Si sensor that can operate with solar blindness. These filters take advantage of the improved admittance with silicon to significantly improve throughput over conventional stand-alone bandpass filter elements. At far ultraviolet wavelengths these filters require the use of non-absorbing dielectrics such as the metal fluoride materials of MgF_2, AlF_3 and LiF. The latest performance of these 1D multilayer filters on Si photodiodes and CCD imaging sensors is demonstrated. We have also extended these 1D structures to more complex multilayers guided by the design concepts of metamaterials and metatronics, and to 2D patterned plasmonic hole array filters fabricated in aluminum. The performance of sensors and test filter structures is presented with an emphasis on UV throughput.