Modeling of pixel edge effects in a novel micro-filter array for the visible spectrum

The modeling of a novel filter for the visible spectrum, constructed of an array of micron sized Fabry-Perot band-pass filters, is presented. An example filter array consists of a hyperspectral 5x5 sub-array, where each squared cavity pixel, 9 mu m wide, is resonating at a different wavelength than the neighboring pixels. For such small cavities, traditional 1D modeling of Fabry-Perot cavities of infinite extent is insufficient. To study pixel edge effects and pixel cross-talk, 2D FDTD simulations were carried out. Extensive modeling was done for a cavity array with several pixels, and sloped cavity edges were compared to vertical ones. Both the optical field inside each cavity, and the corresponding integrated power over the whole cavity were calculated. Comparisons of the peak power and spectral bandwidth were made between a finite pixel cavity and a cavity of infinite extent. Both normal and oblique incident light was included in the simulations.