Broadband fiber optic tap
AssigneeEigenlight Corporation
InventorCraig D. Poole
Life of this patent
Estimating the term…
Abstract
A broadband optical fiber tap for transferring optical energy out of an optical fiber having an optical fiber with a primary and secondary microbends for the purpose of coupling optical energy into the higher-order modes of the fiber, and a reflecting surface formed in the cladding of the fiber and positioned at an angle so as to reflect, by total internal reflection, higher-order mode energy away from the optical fiber. In the preferred embodiment, the two microbends are spaced apart by a distance approximately equal to one-half of the intermodal beat length for LP01 and LP11 modes of a single-mode fiber.
Claims8
A broadband fiber optic tap for efficiently transferring optical energy out of an optical fiber over a broad wavelength range, the tap comprising:
- an optical fiber containing a core and a cladding;
- a first structure formed in the fiber that transfers optical energy from a guided mode to a first unguided mode of said optical fiber;
- a second structure, formed in the fiber and situated at a pre-defined distance, Δ, in a direction of optical propagation downstream from said first structure, that transfers optical energy from said first unguided mode back into said guided mode and into a second unguided mode of said optical fiber, said second unguided mode being a higher-order mode than the first unguided mode;
- and
- a reflecting surface formed in the cladding of said optical fiber and situated at a pre-defined distance, d, in a direction of optical propagation downstream from said first structure for reflecting optical energy propagating in said cladding out of the side of said fiber.
A fiber optic tap for transferring optical energy out of an optical fiber, the tap comprising:
- an optical fiber containing a core and a cladding;
- a first structure formed in the fiber that couples optical energy between at least two modes of said optical fiber;
- a second structure formed in the fiber and situated at a pre-defined distance from said first structure that couples optical energy between said two modes of said optical fiber;
- and
- a reflecting surface formed in the cladding of said optical fiber and situated at a pre-defined distance, d, in a direction of optical propagation downstream from said first structure for reflecting optical energy out of the side of said fiber;
- wherein said distance d is given by the following equation:
- n
- clad
-
- D
- NA
- <
- d
- <
- 2
-
- n
- clad
-
- D
- NA
- where:
- nclad is an index of refraction of the cladding material,
- D is a diameter of the fiber, and
- NA is a numerical aperture of the fiber.
A fiber optic tap for transferring optical energy out of an optical fiber, the tap comprising:
- an optical fiber containing a core and a cladding;
- a first structure formed in the fiber that couples optical energy between at least two modes of said optical fiber;
- and
- a reflecting surface formed in the cladding of said optical fiber and situated at a pre-defined distance, d, in a direction of optical propagation downstream from said first structure for reflecting optical energy out of the side of said fiber;
- wherein said distance d is given by the following equation:
- n
- clad
-
- D
- NA
- <
- d
- <
- 2
-
- n
- clad
-
- D
- NA
- where:
- nclad is an index of refraction of the cladding material,
- D is a diameter of the fiber, and
- NA is a numerical aperture of the fiber.
Dependencies are inferred from the claim text.