Efficient coupling of light into a light guides
AssigneeKoninklijke Philips Electronics N.V.
InventorDuncan J. Anderson
Life of this patent
Estimating the term…
Abstract
Method and apparatus of coupling light into a light guide using error detecting and correcting systems. A rectangular light guide is mated with an X-axis optical fiber and with a Y-axis optical fiber. An X-axis photodetector senses light that couples from the light guide into the X-axis optical fiber, while a Y-axis photodetector senses light that couples from the light guide into the Y-axis optical fiber. An error detector compares the outputs of the X-axis and the Y-axis photodetectors to produces error signals that depend on the X-axis, the Y-axis, and the Z-axis positional errors. The errors signals are applied to an error correcting system that adjusts the relative position of the light guide and the light directed onto the light guide.
Claims23
An optical system, comprising:
- a rectangular light guide having an inner core and an outer cladding layer;
- a first optical fiber that is optically coupled to a first side of the outer cladding layer and is configured to detect light that is propagating within the first side of the outer cladding layer;
- a second optical fiber that is optically coupled to a second side of the outer cladding layer and is configured to detect light that is propagating within the second side of the outer cladding layer;
- a first photodetector for sensing light coupled into the first optical fiber;
- and
- a second photodetector for sensing light coupled into the second optical fiber.
An image projection system, comprising:
- a rectangular light guide having an inner core and an outer cladding layer;
- a light source for projecting a light beam into the light guide;
- a first optical fiber optically coupled to a first side of the outer cladding layer that is configured to detect light that is propagating within the first side of the outer cladding layer;
- a second optical fiber optically coupled to a second side of the outer cladding layer that is configured to detect light that is propagating within the second side of the outer cladding layer;
- a first photodetector for sensing light coupled into the first optical fiber;
- and
- a second photodetector for sensing light coupled into the second optical fiber.
A method of coupling light into a rectangular light guide, comprising:
- directing light into a light guide having a cladding layer;
- removing a first portion of the light that is directed into and propagates within the cladding layer on a first side of the rectangular light guide, wherein the first portion is removed along an X-axis;
- removing a second portion of the light that is directed into and propagates within the cladding layer on a second side of the rectangular light guide that is substantially orthogonal to the first side, wherein the second portion is removed along a Y-axis;
- sensing the first portion of the light to determine an X-axis misalignment of the light;
- and
- sensing the second portion of the light to determine a Y-axis misalignment of the light.
Dependencies are inferred from the claim text.