LIDAR with increased emitted laser power

• US 20020063858A1
• Filed: 11/29/2000
• Published: 05/30/2002
• Est. Priority Date: 11/29/2000
• Status: Active Grant

• Current Assignee: Kustom Signals Incorporated (MPD Incorporated)
• Original Assignee: PATCO Properties, Inc.
• Inventors: Patterson, Scott W.
• Granted Patent: US 6,441,889 B1
• Time in Patent Office: Days
• US Class Current: 356/28
• CPC Class Codes: G01S 7/4814 of transmitters alone
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/4031 Edge-emitting structures

Abstract

A traffic LIDAR device is presented with an increased laser power output in compliance with the IEC 825 standard for class one-type laser systems. Increased laser emitter power output is accomplished by reshaping the emitter source output using an optical fiber which has an inside diameter greater than the minimum dimension of the emitter source. The resulting increased cross-section of the output pulse overcomes the power output limitation that would otherwise be dictated by the emitter minimum dimension.

Claims

1. In a LIDAR device, a method for increasing the usable emitted laser power comprising the steps of:

emitting a laser pulse from an emitter source having a predetermined minimum emitter dimension,

injecting said emitted laser pulse into a first end of an optical fiber having a transverse dimension greater than said predetermined dimension,

reshaping said injecting laser pulse within said optical fiber, and

emitting said reshaped laser pulse from a second end of said optical fiber to provide an output pulse in which the energy of the laser is spread over an increased area.

2. The method as claimed in claim 1 wherein said reshaped pulse presents a generally circular transmission pattern.

3. The method as claimed in claim 1 wherein said reshaped laser pulse presents a homogeneous output.

4. An increased-power laser emitter for a LIDAR device comprising:

an emitter source for producing a laser pulse, said source having a predetermined minimum emitter dimension,

an optical fiber having an input, an output spaced from said input, and an inside dimension of the fiber between said input and output greater than said predetermined minimum emitter dimension,

means for injecting said laser pulse into said input of said optical fiber, and

means in said fiber responsive to said injected laser pulse for providing a laser output pulse from said output having an increased cross-sectional size, thereby increasing the apparent size of the emitter source.

5. The device as claimed in claim 4 wherein said laser output pulse presents a generally circular transmission pattern.

6. The device as claimed in claim 4 wherein said laser output pulse presents a homogenous output.

7. The device as claimed in claim 4 wherein said emitter source has a predetermined maximum emitter dimension, and said optical fiber inside dimension is greater than said predetermined maximum emitter dimension, whereby substantially all of said laser pulse is injected into said input of said optical fiber.

8. The device as claimed in claim 4 wherein said emitter source has a predetermined maximum emitter dimension, and said optical fiber inside dimension is less than said predetermined maximum emitter dimension, whereby a portion of said laser pulse is injected into said input of said optical fiber.

9. The device as claimed in claim 4 wherein said inside dimension of said optical fiber is approximately 0.2 millimeter to 0.7 millimeter.

10. The device as claimed in claim 4 wherein said emitter source produces said laser pulse with a predetermined transmission pattern, and said optical fiber inside dimension is less than said predetermined transmission pattern, whereby a portion of said laser pulse is injected into said input of said optical fiber.