High power acoustic resonator with integrated optical interfacial elements

• US 20080030714A1
• Filed: 08/04/2006
• Published: 02/07/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Jiang, Li, Tustin, Gary J., Hall, Clive E., Jones, Timothy G.J.
• Granted Patent: US 7,804,598 B2
• Time in Patent Office: Days
• US Class Current: 356/72
• CPC Class Codes: B08B 17/02 Preventing deposition of fouling or of dust
• CPC Class Codes: B08B 3/12 by sonic or ultrasonic vibrations washing or rinsing machines for crockery or tableware using sonic or ultrasonic waves A47L15/13; of natural teeth, of prostheses using ultrasonic techniques similar to those used for natural teeth A61C17/20; application of ultrasonic vibrations to chemical, physical or physico-chemical processes in general B01J19/10
• CPC Class Codes: B08B 7/028 Using ultrasounds
• CPC Class Codes: G01N 2021/154 Ultrasonic cleaning
• CPC Class Codes: G01N 21/15 Preventing contamination of the components of the optical system or obstruction of the light path
• CPC Class Codes: G01N 21/25 Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B

Abstract

Embodiments of the present invention provide methods and systems for integrating optical interfacial elements with a high power acoustic resonator. More specifically, but not by way of limitation, in certain embodiments of the present invention, one or more optical interfacial elements may be integrated with a high power acoustic resonator to provide a robust sensing device that may provide for acoustic cleaning of the optical interfacial elements and/or combining optical and acoustic measurements made by the integrated system for analysis purposes. In certain aspects, the high power acoustic resonator may include an acoustic horn for focusing acoustic energy and the optical interfacial elements may be integrated with the acoustic horn.

Claims

1. An optical interfacial element integrated with a high power acoustic resonator to provide for acoustic cleaning of an optical surface or surfaces of the optical interfacial element, comprising:

a high power acoustic resonator, wherein the high power acoustic resonator comprises;

an acoustic body having a first end and a second end, wherein the first end comprises a base of the acoustic body and the second end defines a surface with an opening disposed in the defined surface configured to provide access to an interior of the acoustic body;

a transducer coupled with the first end and configured to vibrate the acoustic body;

an optical interfacial element coupled with the acoustic body, disposed at or proximal to the opening and configured to provide for the transmission of electromagnetic radiation into and out of the optical interfacial elements, wherein;

the optical interfacial element is also configured to seal the interior of the acoustic body from an external environment; and

the acoustic body is configured to provide for transmitting the vibrations of the acoustic body onto the acoustic element to acoustically clean the optical element;

an optical system configured to provide an optical path or paths between the first end of the acoustic body and the optical interfacial element located in the opening in the second end of the acoustic body.

2. The system of claim 1, wherein the optical system passing from the first end to the second end of the acoustic body is disposed entirely within a volume defined by an outer surface of the acoustic body.

3. The system of claim 1, wherein the second end of the acoustic body defines a plane surface.

4. The system of claim 1 wherein the second end of the acoustic body is positioned to experience an antinode during vibration of the high power acoustic resonator.

5. The system of claim 1, wherein the high power acoustic resonator is configured to operate in a longitudinal mode.

6. The system of claim 1, wherein the optical system comprises an optical fiber.

7. The system of claim 1, wherein the optical system comprises a light pipe.

8. The system of claim 1, wherein the optical system comprises at least one optically reflective surface.

9. The system of claim 1, wherein the optical system comprises at least one optically refractive surface.

10. The system of claim 1, wherein the optical system comprises at least one optically diffractive surface.

11. The system of claim 1, wherein the acoustic body comprises an acoustic horn.

12. The system of claim 1, wherein the optical element and optical system are configured to operate in the mid-infrared spectral region.

13. The system of claim 1, wherein the optical interfacial element comprises one of natural diamond, synthetic diamond, sapphire, silica, silicon, germanium, zinc selenide, zinc sulphide, barium fluoride, calcium fluoride and yttrium oxide.

14. The system of claim 1, wherein the acoustic body comprises titanium.

15. The system of claim 1, wherein the acoustic body comprises stainless steel

16. The system of claim 1, wherein the transducer comprises a piezoelectric element.

17. The system of claim 1, further comprising:

an electromagnetic radiation source coupled with the optical system; and

an electromagnetic radiation detector coupled with the optical system.

18. The system of claim 1, wherein the electromagnetic radiation source is configured to emit electromagnetic radiation with a wavelength in a region of between 2 and 25 μ

m.

19. The system of claim 1, wherein the electromagnetic radiation source comprises a laser.

20. The system of claim 1, wherein the optical element is disposed at a distance less than or equal to λ

/5 from the surface defined by the second end of the acoustic body, and wherein λ

is the wavelength of an acoustic wave generated by the high power acoustic resonator in the acoustic horn.

21. The system of claim 1, further comprising:

a processor coupled with the high power acoustic resonator, the electromagnetic radiation source and the electromagnetic radiation detector and configured to control the high power acoustic resonator, the electromagnetic radiation source and the electromagnetic radiation detector.

22. The system of claim 1, wherein the optical system passes through the transducer.

23. The system of claim 1, wherein the optical interfacial element integrated with the high power acoustic resonator is configured to function at temperatures in excess of 200 degrees Centigrade.

24. The system of claim 1, wherein the optical interfacial element integrated with the high power acoustic resonator is configured to function in fluid pressures exceeding 700 bar.

25. An optical interfacial device with combined optical and acoustical elements configured to provide for analyzing a material located at or near an optical interfacial element, comprising:

a high power acoustic resonator, wherein the high power acoustic resonator comprises;

an acoustic body having a first end and a second end, wherein the first end comprises a base and the second end defines a surface with an opening in said defined surface;

a transducer coupled with the first end and configured to vibrate the acoustic body, wherein the acoustic body is configured to transmit acoustic energy produced by the high power acoustic resonator onto the surface defined by the second end;

an optical system disposed within the high power acoustic resonator and configured to provide an optical path or paths from the first end to the opening in the surface defined by the second end; and

the optical interfacial element coupled with the second end of the acoustic body and disposed to provide for transmission of electromagnetic radiation into or out of the optical system through said optical interfacial element, wherein the optical interfacial element is further configured to seal the opening from an external environment, and wherein the optical interfacial element is configured to provide an external interface for optically analyzing the material.

26. The system of claim 25, wherein the optical interfacial element is configured to contact a material to be optically analyzed.

27. The system of claim 25, wherein the optical element is disposed at or proximal to the surface defined by the second end of the acoustic body.

28. The system of claim 25, wherein the second end of the acoustic body is located at a position such that the second end of the acoustic body experiences an antinode during vibration of the high power acoustic resonator.

29. The system of claim 25, wherein the optical system comprises an optical fiber.

30. The system of claim 25, wherein the optical system comprises a light pipe.

31. The system of claim 25, further comprising:

moveable mirrors configured to direct electromagnetic radiation onto and back from the optical interfacial element.

32. The system of claim 25, wherein the optical interfacial element comprises a prism.

33. The system of claim 25, wherein the optical interfacial element comprises a window.

34. The system of claim 25, wherein the optical interfacial element comprises a refractive or diffractive lens.

35. The system of claim 25, wherein the prism is shaped as one of a cone, and a truncated cone.

36. The system of claim 32, wherein the prism has a cross-sectional shape of one of a triangle, a truncated triangle, a semicircle, and a long thin rectangle.

37. The system of claim 25, wherein the optical interfacial element is configured to provide for formation of a totally internally reflecting surface when in contact with the material to be analyzed, wherein the electromagnetic radiation is reflected from the totally internally reflecting surface.

38. The system of claim 25, wherein the acoustic body comprises an acoustic horn.

39. The system of claim 25, wherein a resonant frequency of the high power acoustic resonator is in the range of 10 kHz to 250 kHz.

40. The system of claim 25, wherein the acoustic body is configured to transmit acoustic energy onto the sensing surface to provide for exertion of a physical force onto a substance located or deposited on the external interface.

41. The system of claim 25, wherein the optical interfacial element comprises one of natural diamond, synthetic diamond, sapphire, silica, silicon, germanium, zinc selenide, zinc sulphide, barium fluoride, calcium fluoride and yttrium oxide.

42. The system of claim 25, wherein the acoustic body comprises titanium.

43. The system of claim 25, wherein the acoustic body comprises stainless steel

44. The system of claim 25, wherein the transducer comprises a piezoelectric element.

45. The system of claim 25, further comprising:

an electromagnetic radiation source coupled with the optical system; and

an electromagnetic radiation detector coupled with the optical system.

46. The system of claim 45, wherein the electromagnetic radiation source is configured to emit electromagnetic radiation with a wavelength in a region of between 2 and 25 μ

m.

47. The system of claim 45, wherein the electromagnetic radiation source comprises a laser.

48. The system of claim 45, further comprising:

a processor coupled with the high power acoustic resonator, the electromagnetic radiation source and the electromagnetic radiation detector and configured to control the high power acoustic resonator, the electromagnetic radiation source and the electromagnetic radiation detector and to receive measurements from the high power acoustic resonator, the electromagnetic radiation source and the electromagnetic radiation detector.

49. The system of claim 48, wherein the processor is configured to process a resonant frequency of the high power acoustic resonator and an amount of electromagnetic radiation detected by the electromagnetic radiation detector.

50. The system of claim 38, wherein the optical interfacial element is disposed at a distance less than or equal to λ

/5 from the surface defined by the second end of the acoustic body, and wherein λ

is wavelength of an acoustic wave in the acoustic horn.

51. The system of claim 25, wherein the optical system passes through the transducer.

52. The system of claim 25, wherein the optical interfacial device with combined optical and acoustical elements is configured to function at temperatures in excess of 200 degrees Centigrade.

53. The system of claim 25, wherein the optical interfacial device with combined optical and acoustical elements is configured to function in fluid pressures exceeding 700 bar.

54. The system of claim 25, wherein the optical interfacial device with combined optical and acoustical elements is configured for use in a borehole penetrating an earth formation.

55. A method for acoustically cleaning an optical interfacial element integrated with a high power acoustic resonator, comprising the steps of:

vibrating the high power acoustic resonator, wherein the high power acoustic resonator is coupled with the optical interfacial element; and

transmitting the vibrations of the high power acoustic resonator onto the optical interfacial element to provide for acoustic cleaning of the optical element.

56. The method for acoustically cleaning the optical interfacial element as recited in claim 55, wherein amplification of vibrations from the high power acoustic resonator is achieved by shaping an acoustic horn and integrating an optical conduit to the optical interfacial element within the acoustic horn.

57. A method for acousto-optically determining physical properties of a substance located at a sensing surface of a high power acoustic resonator, the sensing surface comprising a surface of an optical interfacial element that is optically coupled with an optical conduit passing through the high power acoustic resonator, comprising the steps of:

oscillating the high power acoustic resonator in a resonance mode;

monitoring a frequency of the resonance mode of the high power acoustic resonator;

transmitting a beam of electromagnetic radiation down the optical conduit, through the optical element and onto the substance;

reflecting a portion of the beam of electromagnetic radiation from the substance or transmitting the beam through the substance;

measuring one or more spectral properties of the portion of the electromagnetic beam reflected from, or transmitted through, the substance; and

processing the frequency of the resonance mode and the one or more spectral properties to determine the physical properties of the substance

58. The method of claim 57, wherein reflecting a portion of the beam of electromagnetic radiation comprises creating an internal reflection surface from which a portion of the electromagnetic beam is reflected.

59. The method of claim 57, wherein the step of oscillating the high power acoustic resonator in a resonance mode comprises longitudinally oscillating the high power acoustic resonator.