System and method for an interferometer resistant to externally applied forces

Patent metadata

Field	Value
Publication number	US-10670462-B2
Application number	US-201815920999-A
Country	US
Kind code	B2
Filing date	Mar 14, 2018
Priority date	Mar 16, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

An embodiment of a ruggedized interferometer is described that comprises a light source that generates a beam of light; a fixed mirror; a moving mirror that travels along a linear path; a beam splitter that directs a first portion of the beam of light to the fixed mirror and a second portion of the beam of light to the moving mirror, wherein the beam splitter recombines the first portion reflected from the fixed mirror and the second portion reflected from the moving mirror; and a servo control that applies a substantial degree of force to the moving mirror at initiation of a turnaround period, wherein the substantial degree of force is sufficient to redirect the moving mirror traveling at a high velocity to an opposite direction of travel on the linear path.

First claim

What is claimed is:

1. A ruggedized interferometer, comprising:
a light source that generates a beam of light;
a fixed mirror;
a moving mirror that travels along a linear path;
a drive coil;
a beam splitter that directs a first portion of the beam of light to the fixed mirror and a second portion of the beam of light to the moving mirror, wherein the beam splitter recombines the first portion reflected from the fixed mirror and the second portion reflected from the moving mirror; and
a servo control that at initiation of a turnaround period employs the drive coil to apply a substantial degree of force of about 50-300 grams to the moving mirror traveling at a steady state velocity that is greater or equal to 3 cm/s, wherein the substantial degree of force reverses the direction of travel of the moving mirror and the servo control maintains the application of the substantial degree of force until the moving mirror reaches the steady state velocity.

2. The ruggedized interferometer of claim 1 , wherein:
the servo control employs a hybrid control scheme to switch from closed loop control to open loop control at the initiation of the turnaround period and to switch from open loop control to closed loop control upon reversal of the direction of travel of the moving mirror.

3. The ruggedized interferometer of claim 2 , wherein:
the servo control employs the drive coil to apply a force to the moving mirror to maintain the steady state velocity under closed loop control.

4. The ruggedized interferometer of claim 1 , wherein:
the fixed mirror further comprises a dynamic alignment system comprising one or more tuning elements with rigid characteristics.

5. The ruggedized interferometer of claim 4 , wherein:
the one or more tuning elements comprise a piezo actuator.

6. The ruggedized interferometer of claim 4 , wherein:
the one or more tuning elements comprise a mechanical actuator.

7. The ruggedized interferometer of claim 4 , wherein:
the dynamic alignment system further comprises a coarse tuning mechanism with rigid characteristics.

8. The ruggedized interferometer of claim 7 , wherein:
the coarse tuning mechanism comprises a lead screw or a stepper motor.

9. The ruggedized interferometer of claim 7 , wherein:
the tuning elements and coarse tuning mechanism provide an additive range of compensation.

10. The ruggedized interferometer of claim 1 , further comprising:
a motion detector that measures forces enacted on the ruggedized interferometer positioned on a non-moving portion of a body of the ruggedized interferometer and that provides information to the servo control to modify an amount of the substantial degree of force applied to the moving mirror.

11. The ruggedized interferometer of claim 10 , wherein:
the motion detector comprises an accelerometer.

12. The ruggedized interferometer of claim 1 , further comprising:
a motion detector that measures forces enacted on the ruggedized interferometer positioned on an end plate and that provides information to make a positional adjustment to the fixed mirror.

13. The ruggedized interferometer of claim 1 , further comprising:
a detector.

14. The ruggedized interferometer of claim 13 , wherein:
the detector comprises a fast detector.

15. The ruggedized interferometer of claim 14 , wherein:
the fast detector comprises a mercury cadmium telluride (MCT) detector.

16. The ruggedized interferometer of claim 13 , wherein:
the detector comprises a slow detector.

17. The ruggedized interferometer of claim 16 , wherein:
the slow detector comprises a triglycine sulfate (TGS) detector.

18. The ruggedized interferometer of claim 1 , further comprising:
one or more shock absorbing structures.

19. The ruggedized interferometer of claim 18 , wherein:
the one or more shock absorbing structure comprise rubber feet.

20. The ruggedized interferometer of claim 18 , wherein:
the one or more shock absorbing structure comprise wire rope isolators.

21. The ruggedized interferometer of claim 1 , wherein:
the substantial degree of force comprises a maximum allowable force.

22. The ruggedized interferometer of claim 1 , wherein:
the substantial degree of force comprises a force of about 100 grams.

23. The ruggedized interferometer of claim 1 , wherein:
the high velocity comprises a velocity of about 8.2 cm/s.

24. The ruggedized interferometer of claim 12 , wherein:
the motion detector comprises an accelerometer.

Assignees

• Thermo Electron Scient Instruments Llc

Inventors

• Coffin John Magie
• Georgiadis Michael S
• Chou Jei Y

Classifications

• G01J3/4535 Primary

  Devices with moving mirror (G01J3/4532 takes precedence) · CPC title

• G01J2003/4538

  Special processing · CPC title

• G01J3/06

  Scanning arrangements {arrangements for order-selection} · CPC title

• H02P25/034

  Voice coil motors (voice coil motors driven by DC H02P7/025) · CPC title

• G01J3/0297

  Constructional arrangements for removing other types of optical noise or for performing calibration · CPC title