IP Library › Granted Patent US 12,449,298
Granted Patent B2
US 12,449,298 · App. 18/138,485 · Granted Oct 21, 2025

Power monitoring in fiber-coupled laser systems

Inventors: Scott R. Karlsen (Battleground, WA); David R Balsley (Portland, OR); Nicolas Trent Meacham (Vancouver, WA); Austin Hagarty (Camas, WA); Dahv A. V. Kliner (Portland, OR)
Assignee: nLIGHT, Inc.
G01J1/4257G01J1/0414G01J1/0437
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Quick Facts
Patent No.
US 12,449,298
App. No.
18/138,485
Granted
Oct 21, 2025
Kind
B2
Abstract

Some embodiments may include a power monitor to measure power of laser light propagating in a core of an optical fiber; the power monitor to generate a sensor signal using an optical sensor having a light sensitive section with no line of sight to part of the optical fiber; wherein the sensor signal is derived from light emerging laterally from the part of the optical fiber. Other embodiments may be disclosed and/or claimed.

Claims (48)

1. An apparatus, comprising:

a power monitor comprising an active optical fiber, an optical sensor having a light sensitive section, one or more light obstructions located on a side of the active optical fiber between the active optical fiber and the optical sensor that block a line of sight from the light sensitive section to the side of the active optical fiber, and a gap provided between a part of the one or more light obstructions and a light-processing surface,

wherein the optical sensor generates electrical signals indicative of one or more characteristics of laser light propagated in a core of the active optical fiber,

wherein the power monitor measures power of laser light propagating in the core of the active optical fiber and generates

a sensor signal using the optical sensor; and

wherein the sensor signal is uses a second light that emerges from the gap derived from a first light emerging laterally from an exterior of a part of the active optical fiber.

2. The apparatus of claim 1 , wherein the power monitor outputs the sensor signal to processing circuitry coupled to the optical sensor.

3. A fiber-coupled laser system employing the power monitor of claim 2 , wherein the active optical fiber is coupled to a laser source that generates the laser light.

4. The apparatus of claim 3 , wherein the processing circuitry generates a control signal to adjust one or more operating characteristics of the fiber-coupled laser system based on the measured power.

5. The apparatus of claim 1 , wherein the optical sensor is positioned so that the light sensitive section faces away from the part of the active optical fiber.

6. A method of measuring power or one or more other characteristic of laser light propagating in a core of an active optical fiber of a fiber-coupled laser system based on a first light emerging laterally from an exterior of a part of the active optical fiber, the method comprising:

receiving second light by an optical sensor having a light sensitive section, wherein the second light emerges from a gap provided between a part of one or more light obstructions and a light-processing surface, the one or more light obstructions located on a side of the active optical fiber between the active optical fiber and the optical sensor that block a line of sight from the light sensitive section to the side of the active optical fiber, the second light derived from the first light;

generating a sensor signal by the optical sensor in response to receipt of the second laser light; and

outputting the sensor signal to processing circuitry coupled to the optical sensor.

7. The method of claim 6 , further comprising:

generating a control signal for the fiber-coupled laser system using the processing circuitry.

8. The method of claim 6 , further comprising:

storing an output of the processing circuitry in a hardware memory.

9. The method of claim 6 , further comprising at least partially partitioning an enclosure into a first section and a second section, wherein the part of the active optical fiber is located in the first section of the enclosure and the optical sensor is located in the second section of the enclosure.

10. The method of claim 6 , further comprising at least partially partitioning an integrating volume into a first section and a second section, wherein the part of the active optical fiber is located in the first section of the integrating volume and the optical sensor is located in the second section of the integrating volume.

11. A power monitor to measure power of laser light propagated in a core of an active optical fiber, the power monitor comprising:

an enclosure through which the active optical fiber is disposed, wherein first light emerges laterally from an enclosed part of the active optical fiber;

an optical sensor comprising a light sensitive section, wherein the optical sensor generates electrical signals indicative of one or more characteristics of laser light propagated in the core of the active optical fiber;

one or more light obstructions located on a side of the active optical fiber between the active optical fiber and the optical sensor that block a line of sight from the light sensitive section to the side of the active optical fiber;

a gap provided between the part of the one or more light obstructions and a light-processing surface;

wherein the optical sensor receives second light derived from the first light, and generates a sensor signal responsive to a second light that emerges from the gap derived from a first light emerging laterally from an exterior of a part of the active optical fiber; and

a processor connected to the optical sensor;

wherein the processor receives the sensor signal,

wherein the processor derives measurement data from the sensor signal, and

wherein the measurement data comprises the measured power of the laser light propagated in the core of the active optical fiber.

12. The power monitor of claim 11 , wherein the one or more comprising:

light obstructions are disposed within the enclosure between the part of the active optical fiber and the optical sensor,

wherein the one or more light obstructions separate the enclosure into a first section containing the active optical fiber and a second section containing the optical sensor, and

wherein the one or more light obstructions receive a portion of the first light thereby preventing establishment of the line of sight from the light sensitive section to the part of the active optical fiber.

13. The power monitor of claim 11 , further comprising:

wherein the enclosure includes a first section containing the part of the active optical fiber and a second section containing the optical sensor, and

wherein the light sensitive section of the optical sensor faces away from the part of the active optical fiber, thereby preventing establishment of the line of sight from the light sensitive section to the part of the active optical fiber.

14. The power monitor of claim 11 ,

wherein the light-processing surface processes the first light and transmits the second light, and wherein the light-processing surface is ground or roughened.

15. The power monitor of claim 11 ,

wherein the light-processing surface processes the first light and transmits the second light, and wherein the light-processing surface comprises a diffuse reflection surface.

16. The power monitor of claim 15 , wherein the light-processing surface comprises part of an interior of the enclosure.

17. The power monitor of claim 16 , wherein the light-processing surface comprises a plurality of light-processing surfaces including the part of the interior of the enclosure and part of a light obstruction disposed within the enclosure between the part of the active optical fiber and the optical sensor.

18. The power monitor of claim 12 , wherein the one or more light obstructions comprise

a translucent wall or other translucent body, or

a non-transparent wall or other non-transparent body;

wherein the light obstruction is formed from a translucent plastic or other non-transparent material or includes a translucent or other non-transparent surface facing the contained part of the optical fiber.

19. The power monitor of claim 15 , wherein the light-processing surface is located on a flat surface of an interior of the enclosure.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 23, 2023
From: KLINER, DAHV A.V.
To: NLIGHT, INC.
Reel/Frame 063733/0727 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 23, 2023
From: KARLSEN, SCOTT R.; BALSLEY, DAVID R.; MEACHAM, NICOLAS T.; HAGARTY, AUSTIN
To: NLIGHT, INC.
Reel/Frame 063734/0020 →
Continuity (2)
Provisional Application 63336950 · Apr 29, 2022
Related Publication 20230349754A1 · Nov 2, 2023
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