Crossed dot bar graph display for indication of position of a light beam, and an improved laser system with active laser cavity alignment using same

• US 5,047,609 A
• Filed: 01/05/1990
• Issued: 09/10/1991
• Est. Priority Date: 01/05/1990
• Status: Expired due to Fees

• Current Assignee: Spectra-Physics Lasers, Inc. (Perspecta, Inc.)
• Original Assignee: Spectra-Physics Incorporated (MKS Instruments Incorporated)
• Inventors: Ekstrand, John P.
• Primary Examiner(s): Albritton, C. L.
• Application Number:
  US07/461,359
• Time in Patent Office: 613 Days
• Field of Search: 219/121.78, 219/121.83, 219/121.61, 219/121.62, 219/121.79, 219/121.81, 219/121.74, 356/152, 356/138, 356/153, 356/375, 356/376, 356/400, 356/401
• US Class Current: 219/121.78
• CPC Class Codes: B23K 26/04 Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
• CPC Class Codes: G01B 5/252 for measuring eccentricity, i.e. lateral shift between two parallel axes

Abstract

A system for displaying information concerning position of a light beam comprises a detector generating a first signal indicating position of the beam along a first dimension, and a second signal indicating position of the beam along a second dimension. A crossed dot bar graph display is coupled to receive the first and second signals. The crossed dot bar graph display includes a first linear array of indicators (LEDs) for indicating position along the first dimension, and a second linear array of indicators for indicating position along the second dimension. The first and second linear arrays intersect at a center indicator. One dot is displayed in the first array showing deviation in the first dimension. One dot is displayed in the second display showing deviation in the second dimension. When both dimensions are aligned to the center indicator, only the center indicator is activated. The system can be expanded to any number of dimensions.

Claims

1. An apparatus for displaying information concerning position of a light beam;

comprising;

detector means, having a face with a reference point, for generating a first signal indicating position of a light beam incident on the face in a first dimension relative to the reference point, and a second signal indicating position of the light beam incident on the face in a second dimension relative to the reference point;

display means, connected to the detector means, for displaying information concerning position of the beam in response to the first and second signals, including

a first set of indicating means, mounted in a linear array, each of the indicating means in the first set for indicating a respective position in the first dimension of the beam relative to the reference point, and

a second set of indicating means, mounted in a linear array, each of the indicating means in the second set for indicating a respective position in the second dimension of the beam relative to the reference point, wherein

the first and second sets intersect in one member and the respective position indicated by the one member is the reference point in the first dimension or the second dimension.

2. The apparatus of claim 1, wherein the first dimension is perpendicular to the second dimension.

3. The apparatus of claim 1, wherein the first dimension and second dimension intersect at a prespecified angle, and the first linear array and second linear array intersect at the prespecified angle.

4. The apparatus of claim 1, wherein the first linear array has a center at a center point, and the second linear array has a center at the center point, and the one member is positioned in the first and second linear arrays at the center point.

5. The apparatus of claim 1, wherein the indicating means comprise light emitting diodes.

6. In a laser system generating a light beam, and including a cavity mirror mounted on an adjustable mirror mount with control for adjusting the tilt the mirror around an x-axis and a y-axis;

an improvement for providing mirror position information to an operator, comprising;

detector means, having a face with a reference point and coupled with the laser system so that the light beam is incident on the face, for generating a first signal indicating position of the light beam along the x-axis relative to the reference point, and a second signal indicating position of the light beam along the y-axis relative to the reference point; and

display means, connected to the detector means, for displaying information concerning position of the beam in response to the first and second signals, including

a first set of indicating means, mounted in a linear array, each of the indicating means in the first set for indicating a respective position along the x-axis of the beam relative to the reference point, and

a second set of indicating means, mounted in a linear array, each of the indicating means in the second set for indicating a respective position along the y-axis of the beam relative to the reference point;

wherein

the first and second sets intersect in one member and the respective position indicated by the one member is the reference point along the x- and y-axes.

7. The improvement of claim 6, wherein the first linear array has a center at a center point, and the second linear array has a center at the center point, and the one member is positioned in the first and second linear arrays at the center point.

8. The improvement of claim 6, wherein the indicating means comprise light emitting diodes.

9. The improvement of claim 6, wherein the adjustable mirror mount has a dynamic range, and further including;

means for calibrating the first and second linear arrays so that they indicate position of the beam with respect to the dynamic range of the mirror mount.

10. In a laser system generating a light beam, and including a cavity mirror mounted on an adjustable mirror mount with control for adjusting the tilt the mirror around an x-axis and a y-axis and translation of the mirror along a z-axis;

an improvement for providing mirror position information to an operator, comprising;

detector means, having a face with a reference point and coupled with the laser system so that the light beam is incident on the face, for generating a first signal indicating position of the light beam along the x-axis relative to the reference point, and a second signal indicating position of the light beam along the y-axis relative to the reference point;

means, coupled to the laser system, for supplying a third signal indicating position along the z-axis of the mirror with respect to a reference position;

display means, connected to the detector means and the means for supplying, for displaying information concerning position of the beam in response to the first, second and third signals, including

a first set of indicating means, mounted in a linear array, each of the indicating means in the first set for indicating a respective position along the x-axis of the beam relative to the reference point,

a second set of indicating means, mounted in a linear array, each of the indicating means in the second set for indicating a respective position along the y-axis of the beam relative to the reference point, and

a third set of indicating means, mounted in a linear array, each of the indicating means in the third set for indicating a respective position along the z-axis of the beam relative to the reference position;

wherein

the first, second and third sets intersect in one member and the respective position indicated by the one member is the reference point along the x- and y-axes, and the reference position along the z-axis.

11. The improvement of claim 10, wherein the first linear array has a center at a center point, the second linear array has a center at the center point, and the third linear array has a center at the center point, and wherein the one member is positioned in the first, second and third linear arrays at the center point.

12. The improvement of claim 10, wherein the indicating means comprise light emitting diodes.

13. The improvement of claim 10, wherein the tilt of the adjustable mirror mount has a dynamic range, and further including;

means for calibrating the first and second linear arrays so that they indicate position of the beam with respect to the dynamic range of the mirror mount.