Variable optical attenuator with polarization maintaining fiber
AssigneeMolecular OptoElectronics Corporation
InventorsKwok Pong Chan, Kim Roger LaBarge
Life of this patent
Estimating the term…
Abstract
An electrically controllable, variable optical attenuator (VOA) is disclosed, in which polarization maintaining fiber is employed. The fiber is modified to expose the evanescent field of optical energy transmitted therein, by removing material therefrom in a direction parallel to either the fast or slow axis of the fiber, while preserving the polarization maintaining property of the fiber. A controllable material is formed over the modified portion, to remove optical energy in response to a changeable stimulus applied, which changes the refractive index of the material. Related packaging, material composition and system aspects of the attenuator are also disclosed.
Claims58
An attenuator for attenuating optical energy, comprising:
- a portion of a polarization maintaining fiber optic through which the optical energy is transmitted, having a side surface through which at least some of said optical energy can be controllably extracted, the portion of the fiber being modified to allow some of said optical energy to be extracted while maintaining the polarization of the transmitted optical energy;
- a controllable material formed over the side surface of the fiber optic for controllably extracting said optical energy;
- wherein the controllable material controllably extracts the optical energy according to a changeable stimulus applied thereto;
- and
- a housing enclosing the portion of the fiber optic and the controllable material, and wherein the portion of the fiber optic is suspended within the housing to be substantially thermally insulated by surrounding air or other effective thermal insulator in the housing.
An attenuator for attenuating optical energy, comprising:
- a portion of a polarization maintaining fiber optic through which the optical energy is transmitted, having a side surface through which at least some of said optical energy can be controllably extracted, the portion of the fiber being modified to allow some of said optical energy to be extracted while maintaining the polarization of the transmitted optical energy;
- a controllable material formed over the side surface of the fiber optic for controllably extracting said optical energy;
- wherein the controllable material has its optical dispersion properties tailored in accordance with those of the fiber across a given wavelength band.
A method for forming an attenuator in relation to a portion of a fiber optic through which optical energy is to be transmitted, comprising:
- providing a portion of a polarization maintaining fiber optic through which the optical energy is transmitted, having a side surface through which at least some of said optical energy can be controllably extracted, the portion of the fiber being modified to allow some of said optical energy to be extracted while maintaining the polarization of the transmitted optical energy;
- suspending the portion of the fiber optic in a housing;
- mounting a stimulus source in the housing;
- forming a controllable material on a control surface of the stimulus source, the controllable material for controllably extracting the optical energy according to a stimulus from the stimulus source;
- and
- bringing the portion of the fiber optic into contact with the controllable material that the side surface of the portion of the fiber optic is substantially covered by the controllable material;
- wherein the stimulus comprises temperature, and the portion of the fiber optic is substantially thermally insulated by surrounding air or other effective thermal insulator in the housing.
A method for forming an attenuator in relation to a portion of a fiber optic through which optical energy is to be transmitted, comprising:
- providing a portion of a polarization maintaining fiber optic through which the optical energy is transmitted, having a side surface through which at least some of said optical energy can be controllably extracted, the portion of the fiber being modified to allow some of said optical energy to be extracted while maintaining the polarization of the transmitted optical energy;
- disposing the portion of the fiber optic in a housing;
- mounting a stimulus source in the housing;
- forming a controllable material on a control surface of the stimulus source, the controllable material for controllably extracting the optical energy according to a stimulus from the stimulus source;
- and
- bringing the portion of the fiber optic into contact with the controllable material such that the side surface of the portion of the fiber optic is substantially covered by the controllable material;
- wherein the controllable material has its optical dispersion properties tailored in accordance with those of the fiber across a given wavelength band.
Dependencies are inferred from the claim text.