The miniaturization of photodetectors often comes at the expense of a smaller photosensitive area. This can reduce the
signal and thus limit the image quality. One way to overcome this limitation is to reduce the photosensitive area but with
no reduction of signal i.e. harvest the light. Here we investigate, theoretically and experimentally, light harvesting with
nanostructured metals. Nanostructured metals can also give additional functionality such as polarization filtering which
is also investigated. After defining the figure of merits used when characterizing light harvesting and polarization
filtering structures, we detail the fabrication and measurement process. Structures were made on glass substrate, as a post
process step on CMOS fabricated detectors and directly in the CMOS fabrication of the detectors. The optical
characterization results are presented and compared with theory. Finally, we discuss the challenges and advantages of
integrating metallic nanostructures within the CMOS process.
Enhanced optical transmission (EOT) through subwavelength apertures is usually obtained for p-polarized light. The
present study experimentally investigates EOT for s-polarized light. A subwavelength slit surrounded on each side by
periodic grooves has been fabricated in a gold film and covered by a thin dielectric layer. The excitation of s-polarized
dielectric waveguide modes inside the dielectric film strongly increases the s-polarized transmission. Transmission
measurements are compared with a coupled mode model and show good qualitative agreement. Adding a waveguide can
improve light transmission through subwavelength apertures, as both s and p-polarization can be efficiently transmitted.
We investigate experimentally and numerically the efficiency of surface plasmon polariton excitation by a focused laser
beam using gold ridges. The dependence of the efficiency on geometrical parameters of ridges and wavelength
dependence are examined. The experimental measurements accomplished using leakage radiation microscopy. The
numerical simulations are based on Green's tensor approach.
In this work, we study how extraordinary electromagnetic transmission through an array of holes in a metallic film appears as a function of the number of holes and their distribution. In order to do that, we have used a theoretical formalism able to analyze the optical properties of finite collections of apertures placed at arbitrary positions in a metallic film. First, we analyze how the total transmission in a hexagonal 2D hole array evolves as the number of holes in the array is increased. Secondly, we study what is the minimal system showing extraordinary electromagnetic transmission. We find numerically that a linear chain of holes can be considered as the basic entity with extraordinary transmission properties.