Optical control element
AssigneeNokia Corporation
InventorsOlli-Pekka Hiironen, Harri Järvinen
Life of this patent
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Abstract
An optical control modulator comprises an input to receive light from a light source; a polarization divider to divide the light into two orthogonal plane-polarized light components; a Faraday material which, upon being energized, rotates the plane of polarization of the plane-polarized light as it passes through the material; and an output. The light travels through the Faraday material in opposite directions on a common path. In one embodiment, the light passes once through the Faraday material on a loop path. In another embodiment, the light passes twice through the Faraday material by being reflected by a mirror disposed at a back face of the Faraday material.
Claims22
A modulator comprising
- an input to receive light from a light source and modulate data onto it,
- a polarization divider to convert the light into plane-polarized light,
- a material which upon being energized rotates the plane of polarization of the plane-polarized light as it passes through the material such that energizing and de-energizing the material modulates data onto the light, and
- an output wherein the light travels through the material in opposite directions on a common path.
An optical network unit for an optical transmission system comprising a modulator, wherein the modulator comprises
- an input to receive light from a light source and modulate data onto it,
- a polarization divider to convert the light into plane-polarized light,
- a material which upon being energized rotates the plane of polarization of the plane-polarized light as it passes through the material such that de-energizing and energizing the material modulates data onto the light, and
- an output wherein the light travels through the material in opposite directions on a common path.
An optical transmission system comprising at least one modulator, wherein the at least one modulator comprises
- an input to receive light from a light source and modulate data onto it,
- a polarization divider to convert the light into plane-polarized light,
- a material which upon being energized rotates the plane of polarization of the plane-polarized light as it passes through the material such that energizing and de-energizing the material modulates data onto the light, and
- an output wherein the light travels through the material in opposite directions on a common path.
A method of modulating light comprising the steps of:
- receiving light from a light source;
- using a polarization divider to convert the light into plane-polarized light;
- sending the light in opposite directions on a common path through an energizable material;
- and
- energizing the material to rotate the plane of polarization of the plane-polarized light as it travels on the common path such that energizing and de-energizing the material modulates data onto the light.
Dependencies are inferred from the claim text.