title: Improving weak-signal identification via predetection background suppression by a pixel-level, surface-wave enabled dark-field aperture.
abstract: We report the successful implementation of a surface-wave enabled dark-field aperture (SWEDA) directly on a complementary metal-oxide semiconductor sensor pixel (2.2mum). This SWEDA pixel allows predetection cancellation of a uniform coherent background. We show that the signal-to-noise ratio (SNR) of the SWEDA pixel is better than that of a single undressed pixel over a significant range of signal-to-background ratio (SBR). For a small SBR value (SBR=0.001, background intensity=3.96W/m(2), integration time=5ms), we further demonstrate that a SWEDA pixel can detect a weak localized signal buried in a high background, while conventional postdetection background subtraction cannot (improved SNR=2.2 versus SNR=0.26).
authors.affiliation: Department of Electrical Engineering, California Institute of Technology, Pasadena, California 91125, USA. gazheng@caltech.edu
authors.forename: Guoan
authors.initials: G
authors.lastname: Zheng
authors.forename: Changhuei
authors.initials: C
authors.lastname: Yang
mesh_terms: D000465:Algorithms; D000818:Animals; D015374:Biosensing Techniques; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007834:Lasers; D008670:Metals / Q000737:chemistry*; D015233:Models, Statistical; D008962:Models, Theoretical; D055095:Optics and Photonics; D010087:Oxides / Q000737:chemistry*; D012666:Semiconductors; D012984:Software; D020349:Surface Plasmon Resonance / Q000379:methods
chemical_list: D008670:Metals; D010087:Oxides