Method and apparatus for MEMS optical sensing using micromirrors

Abstract

An optical sensing device uses a set of source mirrors directing light from a set of light sources to a movable collector mirror. Each of the light sources has a unique wavelength. The collector mirror is coupled to a MEMS actuator that moves the collector mirror in response to a physical phenomena. A light collector gathers light from the collector mirror and the physical phenomena can be measured by determining the relative intensity associated with each of the light sources in the light gathered at the collector.

1. A sensing device arranged to gather light from one or more light sources, each light source having a unique primary wavelength, comprising:
 one or more source mirrors arranged to reflect light from the respective light sources;  
 a collector mirror arranged to reflect light from the source mirrors;  
 a light collector arranged to gather light reflected from the collector mirror; and  
 a MEMS actuation member coupled to the collector mirror, the MEMS actuation member arranged to move the collector mirror in response to a change in a physical phenomena, wherein movement of the collector mirror causes a change in the relative intensities of the primary wavelengths at the light collector.  
 
     
     
       2. The sensing device of  claim 1 , wherein the one or more source mirrors each comprise a MEMS mirror. 
     
     
       3. The sensing device of  claim 1 , wherein the collector mirror comprises a MEMS mirror. 
     
     
       4. The sensing device of  claim 1 , wherein the MEMS actuation member is arranged to rotate the collector mirror in response to a change in a physical phenomena. 
     
     
       5. The sensing device of  claim 1 , wherein the MEMS actuator comprises a spiral spring, the spiral spring moving the collector mirror in response to a temperature change. 
     
     
       6. The sensing device of  claim 1 , further comprising:
 a sensor housing containing the collector mirror, the MEMS actuator, and the source mirrors; and  
 an interface housing containing at least part of the light collector and at least part of each of the light sources, the interface housing removably attachable to the sensor housing.  
 
     
     
       7. The sensing device of  claim 1 , wherein the light collector and light sources comprise optical fibers. 
     
     
       8. The sensing device of  claim 1 , further comprising one or more collimating lenses between each light source and the respective mirror of the one or more source mirrors. 
     
     
       9. The sensing device of  claim 1 , further comprising a collimating lens between the light collector and the collector mirror. 
     
     
       10. A method of measuring a value of a physical phenomena, comprising:
 directing one or more light beams to one or more respective source mirrors, each light beam having a unique primary wavelength;  
 reflecting the light beams by the respective source mirrors to direct the light beams to a collector mirror, the collector mirror coupled to a MEMS actuator arranged to move the collector mirror in response to the physical phenomena;  
 reflecting the light beams from the collector mirror to a light collector;  
 determining relative intensities of the unique primary wavelengths at the light collector to measure the value of the physical phenomena.  
 
     
     
       11. The method of  claim 10 , further comprising collimating the light beams to focus the light beams on the respective source mirrors. 
     
     
       12. The method of  claim 10 , further comprising collimating the light beams to focus the light beams from the collector mirror to the light collector. 
     
     
       13. The method of  claim 10 , wherein the MEMS actuator comprises a spiral spring, the spiral spring moving the collector mirror in response to a temperature change. 
     
     
       14. The method of  claim 10 , wherein the MEMS actuator is arranged to rotate the collector mirror in response to the physical phenomena. 
     
     
       15. A sensor, comprising:
 one or more light source means each having an associated unique primary wavelength;  
 one or more source reflection means to reflect light from the respective light source means;  
 a collector reflection means to reflect light from the one or more source reflection means into a composite light beam;  
 light collector means to collect the composite light beam; and  
 a MEMS actuation means arranged to displace the collector reflection means in response to a physical phenomena, displacement of the collector reflection means modifying an orientation between the collector reflection means and each of the source reflection means so that a relative intensity of the unique primary wavelengths in the composite beams is modified.  
 
     
     
       16. The sensor of  claim 15 , wherein the source reflection means each comprise a MEMS reflection means. 
     
     
       17. The sensor of  claim 15 , wherein the collector reflection means comprises a MEMS reflection means. 
     
     
       18. The sensor of  claim 15 , wherein the MEMS actuation means is arranged to rotate the source reflection mean. 
     
     
       19. The sensor of  claim 15 , wherein the light collector means and the light source means comprise optical fibers. 
     
     
       20. The sensor of  claim 15 , further comprising:
 sensor housing means for containing the collector reflection means, the MEMS actuation means, and the source reflection means; and  
 an interface housing means for containing at least a part of the light collector means and at least a part of each of the light source means, the interface housing, means removably attachable to the sensor housing means.  
 
     
     
       21. The sensor of  claim 15 , further comprising a collimating means to focus each light source means on the respective source reflection means. 
     
     
       22. The sensor of  claim 15 , further comprising a collimating means to focus the collector reflection means on the light collector means. 
     
     
       23. A sensing device arranged to gather light from a light source, comprising:
 a source mirror arranged to reflect light from the light source;  
 one or more collector mirrors arranged to reflect light from the source mirror,  
 one or more light collectors arranged to gather light reflected from the respective collector mirrors; and  
 a MEMS actuation member coupled to the source mirror, the MEMS actuation member arranged to move the source mirror in response to a change in a physical phenomena, wherein movement of the source mirror causes a change in relative intensities of light measured at the light collectors.  
 
     
     
       24. The sensing device of  claim 23 , wherein the collector mirrors each comprise a MEMS mirror. 
     
     
       25. The sensing device of  claim 23 , wherein the source mirror comprises a MEMS mirror. 
     
     
       26. The sensing device of  claim 23 , wherein the MEMS actuation member is arranged to rotate the source mirror in response to a change in a physical phenomena. 
     
     
       27. The sensing device of  claim 23 , wherein the MEMS actuator comprises a spiral spring, the spiral spring moving the source mirror in response to a temperature change. 
     
     
       28. The sensing device of  claim 23 , further comprising:
 a sensor housing containing the collector mirrors, the MEMS actuator, and the source mirror; and  
 an interface housing containing at least part of the light source and at least part of each of the light collectors, the interface housing removably attachable to the sensor housing.  
 
     
     
       29. The sensing device of  claim 23 , wherein the light collectors and light source comprise optical fibers. 
     
     
       30. The sensing device of  claim 23 , further comprising one or more collimating lenses between each light collector and the respective mirror of the one or more collector mirrors. 
     
     
       31. The sensing device of  claim 23 , further comprising a collimating lens between the light source and the source mirror. 
     
     
       32. A method of measuring a value of a physical phenomena, comprising:
 directing a light beam to a source mirror, the source mirror coupled to a MEMS actuator arranged to move the source mirror in response to the physical phenomena;  
 reflecting the light beam by the source mirror to direct the light beams to one or more collector mirrors,  
 reflecting the light beams from the collector mirrors to one or more respective light collectors;  
 determining relative intensities of the light beam at the light collectors to measure the value of the physical phenomena.  
 
     
     
       33. The method of  claim 32 , further comprising collimating the light beam to focus the light beam on the source mirror. 
     
     
       34. The method of  claim 32 , further comprising collimating the light beam to focus the light beam from the collector mirrors to the respective light collectors. 
     
     
       35. The method of  claim 32 , wherein the MEMS actuator comprises a spiral spring, the spiral spring moving the source mirror in response to a temperature change. 
     
     
       36. The method of  claim 32 , wherein the MEMS actuator is arranged to rotate the source mirror in response to the physical phenomena. 
     
     
       37. A sensor, comprising:
 a light source means;  
 a source reflection means to reflect light from the light source means;  
 one or more collector reflection means to reflect light from source reflection means;  
 one or more light collector means to collect the light from the respective collector reflection means; and  
 a MEMS actuation means arranged to displace the source reflection means in response to a physical phenomena, displacement of the source reflection means modifying an orientation between the source reflection means and each of the collector reflection means so that a relative intensity of light at the light collector means is modified.  
 
     
     
       38. The sensor of  claim 37 , wherein the collector reflection means each comprise a MEMS reflection means. 
     
     
       39. The sensor of  claim 37 , wherein the source reflection means comprises a MEMS reflection means. 
     
     
       40. The sensor of  claim 37 , wherein the MEMS actuation means is arranged to rotate the collector reflection mean. 
     
     
       41. The sensor of  claim 37 , wherein the light collector means and the light source means comprise optical fibers. 
     
     
       42. The sensor of  claim 37 , further comprising:
 sensor housing means for containing the collector reflection means, the MEMS actuation means, and the source reflection means; and  
 an interface housing means for containing at least a part of the light source means and at least a part of each of the light collector means, the interface housing means removably attachable to the sensor housing means.  
 
     
     
       43. The sensor of  claim 37 , further comprising a collimating means to focus the light source means on the source reflection means. 
     
     
       44. The sensor of  claim 37 , further comprising a collimating means to focus each of the collector reflection means on the respective light collector means. 
     
     
       45. A sensing device, comprising:
   one or more source mirrors capable of reflecting light from one or more light sources;        a collector mirror capable of reflecting light from the one or more source mirrors;        a light collector capable of gathering light reflected from the collector mirror; and        a MEMS actuator coupled to the collector mirror, the MEMS actuator being capable of moving the collector mirror in response to a change in an actuating phenomenon, wherein movement of the collector mirror is capable of causing a change in relative intensities of the light at the light collector.     
     
     
       46. The sensing device of  claim 45 , wherein one or more of the source mirrors comprises a MEMS type mirror. 
     
     
       47. The sensing device of  claim 45 , wherein the collector mirror comprises a MEMS type mirror. 
     
     
       48. The sensing device of  claim 45 , wherein the MEMS actuator is capable of rotating the collector mirror in response to a change in an actuating phenomenon. 
     
     
       49. The sensing device of  claim 45 , wherein the MEMS actuator is capable of moving the collector mirror in response to a temperature change. 
     
     
       50. The sensing device of  claim 45 , further comprising:
   a sensor housing containing the collector mirror, the MEMS actuator, or the source mirrors, or combinations thereof; and        an interface housing containing at least part of the light collector or at least part of each of the light sources, or combinations thereof, the interface housing being removably attachable to the sensor housing.     
     
     
       51. The sensing device of  claim 45 , wherein the light collector or the light sources, or combinations thereof, comprise optical fibers. 
     
     
       52. The sensing device of  claim 45 , further comprising one or more collimating lenses disposed between one or more of the light source and one or more of the source mirrors. 
     
     
       53. The sensing device of  claim 45 , further comprising a collimating lens between the light collector and the collector mirror. 
     
     
       54. An apparatus, comprising:
   means for directing one or more light beams;        means for collecting the light beams from said directing means;        means for reflecting the light beams to said collecting means to cause the light beams to impinge upon said collecting means;        means for actuating said reflecting means in response to an actuating phenomenon; and        means for determining the intensity of the one or more light beams impinging upon said collecting means, said determining means being capable of measuring the actuating phenomenon.     
     
     
       55. An apparatus as claimed in  claim 54 , further comprising means for collimating the light beams to focus the light beams on said reflecting means. 
     
     
       56. An apparatus as claimed in  claim 54 , further comprising means for collimating the light beams to focus the light beams on said collecting means. 
     
     
       57. An apparatus as claimed in  claim 54 , said actuating means being responsive to a temperature change. 
     
     
       58. An apparatus as claimed in  claim 54 , said actuating means being capable of rotating said reflecting means in response to the actuating phenomenon. 
     
     
       59. An apparatus, comprising:
   a source mirror arranged to reflect light from a light source;        one or more collector mirrors arranged to reflect light from the source mirror;        one or more light collectors being capable gather light reflected from the one or more collector mirrors; and        a MEMS actuator coupled to the source mirror, the MEMS actuator being capable of moving the source mirror in response to an actuating phenomenon, wherein movement of the source mirror by the MEMS actuator is capable of causing a change in the intensity of light gathered by the one or more light collectors.     
     
     
       60. The sensing device of  claim 59 , wherein one or more of the collector mirrors comprises a MEMS mirror. 
     
     
       61. The sensing device of  claim 59 , wherein the source mirror comprises a MEMS mirror. 
     
     
       62. The sensing device of  claim 59 , wherein the MEMS actuator is capable of rotating the source mirror in response to an actuating phenomenon. 
     
     
       63. The sensing device of  claim 59 , wherein the MEMS actuator is capable of moving the source mirror in response to a temperature change. 
     
     
       64. The sensing device of  claim 59 , further comprising:
   a sensor housing containing the collector mirrors, the MEMS actuator, or the source mirror, or combinations thereof; and        an interface housing containing at least part of the light source or at least part of each of the light collectors, or combinations thereof, the interface housing removably attachable to the sensor housing.     
     
     
       65. The sensing device of  claim 59 , wherein the light collectors or the light source, or combinations thereof, comprise optical fibers. 
     
     
       66. The sensing device of  claim 59 , further comprising one or more collimating lenses disposed between one or more light collector and one or more of the collector mirrors. 
     
     
       67. The sensing device of  claim 59 , further comprising a collimating lens disposed between the light source and the source mirror.