Optical probe, light intensity detection, imaging method and system

Patent metadata

Field	Value
Publication number	US-9869820-B2
Application number	US-201514963988-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Dec 9, 2015
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

Gradient index lenses, or GRIN lenses, are useful for collimating light from a waveguide and reducing loss when coupling two fibers or coupling the fiber to other optical components. There is provided herein a method to align a GRIN lens to the distal end of an optical fiber with precise lateral alignment. The alignment occurs by: (1) rotating the fiber with respect to the lens so that the fiber is parallel with the lens, such that a light is transmitted through the fiber and then through the lens, and (2) translating the fiber laterally with respect to the lens based on the position of a circle pattern that appears on the screen after the distal end of the lens. The transmitted light is centered in the circle pattern for centered alignment or positioned at calculate distance from the center of the circle pattern for off-axis alignment.

First claim

What is claimed is:

1. A method for alignment of an optical fiber to a lens comprising the steps of:
providing a lens having two polished faces,
providing an optical fiber having a polished distal face,
providing a screen positioned for detection of the light transmitted through the lens,
aligning the fiber to the lens by: (1) tipping and tilting the fiber with respect to the lens so that the fiber is parallel with the lens, such that a light is transmitted through the fiber and then through the lens, and (2) translating the fiber laterally with respect to the lens to center the transmitted light within a circle pattern that appears on the screen after the distal end of the lens.

2. The method of claim 1 , wherein the lens is a gradient index (GRIN) lens.

3. The method of claim 1 , wherein at least one of the lens or the optical fiber is secured to at least one stage configured for moving in a lateral direction and at least one of the lens or the optical fiber is secured to at least one stage configured for moving in the direction of optical axis.

4. The method of claim 1 , further comprising tilting and tipping the fiber with respect to the lens such that the transmitted light moves to a calculated position.

5. The method of claim 1 , wherein the rotating of the fiber with respect to the lens comprises one of:
moving the fiber and/or moving the screen where the lens is fixed,
moving the lens and/or moving the fibers where the screen is fixed, or
moving the lens and/or moving the screen, where the fiber is fixed.

6. The method of claim 1 , wherein the translating of the fiber with respect to the lens comprises one of:
moving the fiber and/or moving the screen where the lens is fixed,
moving the lens and/or moving the fibers where the screen is fixed, or
moving the lens and/or moving the screen, where the fiber is fixed.

7. The method of claim 3 , wherein the stage is moved by an automated adjustment mechanism.

8. The method of claim 1 , wherein the fiber is a single mode fiber.

9. The method of claim 1 , wherein the fiber is a multi-mode fiber.

10. The method of claim 1 , wherein the screen is a charged coupled device (CCD).

11. The method of claim 10 , wherein the method further comprises observing an image of the circle pattern on a monitor in communication with the CCD.

12. The method of claim 1 , further comprising using a control panel to rotate and translate at least one of the fiber, lens, and screen in the X, Y, Z, and theta directions.

13. A method for alignment of an optical fiber to a lens comprising the steps of:
providing a lens having two polished faces,
providing an optical fiber having a polished distal face,
providing a screen for detection of the light transmitted through the lens,
aligning the fiber to the lens by: (1) tipping and tilting the fiber with respect to the lens so that the fiber is parallel with the lens, such that a light is transmitted through the fiber and then through the lens, and (2) translating the fiber laterally with respect to the lens based on the position of a circle pattern that appears on the screen after the distal end of the lens when the transmitted light is
centered in the circle pattern, or
positioned at calculate distance from the center of the circle pattern.

Assignees

• Canon Usa Inc
• Canon Usa Inc

Inventors

• Chen Jeffrey
• Yamazoe Kenji

Classifications

• G02B6/32 Primary

  having lens focusing means {positioned between opposed fibre ends (with lens being an integral part of the single fibre end G02B6/262)} · CPC title

• G02B6/3624 Primary

  Fibre head, e.g. fibre probe termination (optical details of light guide terminations G02B6/241; reshaping of light guides G02B6/2552; optical details of coupling light into or out of fibre end G02B6/262) · CPC title

• G02B6/4225

  by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element · CPC title