Optical wavelength filtering by diffraction from a surface relief.
We present an analytical solution to the problem of finding a diffractive surface relief that generates a specific optical amplitude and phase spectral reflection in a particular direction. We show that any discrete finite impulse response filter can be generated to within a multiplicative constant at nonzero frequencies. We propose an implementation of such a filter that works in the visible and the near infrared, based on a two-dimensional array of dual-state tiltable mirrors. A 1024 x 1024 array results in a 1024-tap filter with 10-bit quantization of the impulse response. The applications of such a device include spectroscopy and wavelength-division multiplex switching.
Belikov
Ruslan
R
Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA. rbelikov@stanford.edu
Solgaard
Olav
O