Acousto-optic bandpass filter
AssigneeThe United States of America as represented by the National Security Agency
InventorDuane Anthony Satorius
Life of this patent
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Abstract
The acousto-optic bandpass filter is a device whereby one or more bands of optical wavelengths may be selected for further transmission. In this device, all light within the optical bandwidth of operation is first coupled from the core mode of a optical fiber to a specific cladding mode by a long-period photo-induced grating. These cladding mode lightwaves then enter an acousto-optic interaction region where selected RF frequencies of flexure waves, induced by an acoustic wave amplifier, re-couple selected bands of wavelengths back into the core mode. The interaction region is isolated from the broadband coupler by an acoustic absorber to limit acoustic interaction to the interaction region.
Claims12
An acousto-optic bandpass filter, comprising:
- a non-birefringent single-mode optical fiber, with a longitudinal axis, core, concentric cladding over the core, and proximal and distal ends;
- a broadband cladding mode coupler further comprising a longitudinal length of said optical fiber closer to the proximal end tailored to alter the dispersion properties, a quadratic-dispersion long period grating induced into said optical fiber within said longitudinal length;
- an acousto-optic interaction region further comprising a longitudinal length of said optical fiber closer to the distal end having at least one acoustic wave generator coupled to said optical fiber.
Dependencies are inferred from the claim text.