Tunable, oblique incidence resonant grating filter for telecommunications

Abstract

We have designed a tunable, oblique-incidence resonant grating filter that covers the C band as an add-drop device for incident TE-polarized light. We tune the filter by tilting a microelectromechanical systems platform onto which the filter is attached. The fabrication tolerances as well as the role of finite incident-beam size and limited device size were addressed. The maximum achievable efficiency of a finite-area device as well as a scaling law that relates the resonance peak width and the minimum device size is derived. In good agreement with simulations, measurements indicate a negligible change in shape of the resonance peak from 1526 nm at a 45 degrees angle of incidence to 1573 nm at a 53 degrees angle with a full width at half-maximum of 0.4 nm. In this range the shift of the peak wavelength is linear with respect to changes in the angle of incidence.

Guided-mode resonance excitation of waveguide grating at oblique incidence in the non-subwavelength region

“…Optical elements based on the GMR effect are of increasing importance owing to their applicability in numerous optical systems and devices including communications, nanoelectronics, and laser technology. Examples of present-day uses include filters [3][4][5][6][7], tunable filters [8][9][10][11], sensors [12][13][14], broadband mirrors [15][16][17][18], focusing elements [19,20], wave plates [21] and much more.…”

High Q polarization independent guided mode resonance filters with doubly periodic etched Ta 2 O 5 bi-dimensional grating

“…Yet, in basic configurations, the peak is as selective angularly as spectrally, and illuminate a component having an angular acceptance smaller than the divergence of the incident beam will reduce the spectral selectivity and efficiency of the filter. 2,3 Typically, at 1550nm, GMRF with a bandwidth smaller than 0.2nm should be illuminated with a Gaussian beam with a divergence of 0.08 • , which corresponds to a diameter greater than 3mm. Such a spot size is unpracticable with collimators for signals exiting from fibers, and prevents the miniaturization of the GMRF for integration of several components within a system.…”

Tunable LYOT-filters

“…Etalon, interferometer, and grating filters [1,2,3,4] are essential elements in instrumentation, communication [5], imaging [6], sensing, spectroscopy, and laser [7] systems. The performance of these systems is greatly enhanced if the filters are tunable within a desired band.…”