Irregularly shaped actuator fingers for a micro-electromechanical system fabry-perot filter

• US 7,796,269 B2
• Filed: 08/10/2006
• Issued: 09/14/2010
• Est. Priority Date: 06/06/2006
• Status: Expired due to Fees

• Current Assignee: Morpho Detection (Safran SA)
• Original Assignee: Morpho Detection (Safran SA)
• Inventors: Chandrasekaran, Shankar, Banerjee, Ayan, Goravar, Shivappa, Claydon, Glenn S., Que, Long, Kennerly, Stacey, Hays, David C., Zribi, Anis
• Primary Examiner(s): Chowdhury; Tarifur
• Assistant Examiner(s): Hansen; Jonathan M
• Application Number:
  US11/502,187
• Publication Number:
  US 20100182608A1
• Time in Patent Office: 1,496 Days
• Field of Search: 356/454, 356/480, 356/519, 356/481, 356/517
• US Class Current: 356/454
• CPC Class Codes: G01J 3/06 Scanning arrangements arrangements for order-selection
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

According to one embodiment, a micro-electrical mechanical system apparatus includes (i) a comb drive actuator having at least one irregularly shaped finger and (ii) a movable Fabry-Perot filter cavity mirror coupled to the comb drive actuator. According to some embodiments, a relationship between a voltage applied to the comb drive actuator and an amount of displacement associated with the movable mirror is substantially linear.

Claims

1. A micro-electrical mechanical system apparatus, comprising:

a comb drive actuator;

wherein said comb drive actuator includes a set of movable fingers and a set of anchored fingers;

said set of movable fingers or said set of anchored fingers having a first finger, wherein a surface of said first finger has at least one of;

(i) a saw-tooth profile and (ii) a reverse saw-tooth profile; and

at least one movable Fabry-Perot filter cavity mirror coupled to said comb drive actuator.

2. The apparatus of claim 1, wherein said set of movable fingers includes said first finger.

3. The apparatus of claim 2, wherein said surface of said first finger faces an anchored finger.

4. The apparatus of claim 1, wherein said set of anchored fingers includes said first finger.

5. The apparatus of claim 4, wherein said surface of said first finger faces a movable finger.

6. The apparatus of claim 1, wherein said comb drive actuator comprises a bi-stable device associated with a first latched position and a second latched position.

7. The apparatus of claim 6, wherein said bi-stable device is within a plane and said at least one movable mirror is oriented substantially normal to the plane.

8. The apparatus of claim 7, wherein the plane is defined by a silicon wafer and further comprising:

a fixed mirror oriented substantially normal to the plane and substantially parallel to said at least one movable mirror.

9. The apparatus of claim 1, wherein said Fabry-Perot filter cavity is associated with a spectrometer.

10. The apparatus of claim 9, further comprising:

a light source to provide broadband light scattered from an analyte sample; and

a sensor to sense photons exiting said Fabry-Perot filter cavity over time as said at least one movable mirror is moved by said comb drive actuator.

11. The apparatus of claim 1, wherein a relationship between a voltage applied to said comb drive actuator and an amount of displacement associated with said at least one movable mirror is substantially linear.

12. The apparatus of claim 1, wherein said apparatus is associated with at least one of:

(i) a telecommunication device, (ii) a meteorology device, and (iii) a pressure sensor.

13. A method, comprising:

routing light from a sample of molecules into a tunable Fabry-Perot cavity;

actuating a movable Fabry-Perot filter cavity mirror using a comb drive actuator;

wherein said comb drive actuator includes a set of movable fingers and a set of anchored fingers;

said set of movable fingers or said set of anchored fingers having a first finger, the first finger having a surface that has at least one of;

(i) a saw-tooth profile and (ii) a reverse saw-tooth profile, wherein actuation distances are associated with a spectral range of light wavelengths; and

detecting interference patterns across the spectral range.

14. The method of claim 13, further comprising:

comparing the detected interference pattern with a signature pattern associated with a particular molecule.

15. The method of claim 14, further comprising:

providing an indication based on said comparing.

16. A spectrometer, comprising:

a laser source;

an analyte sample to reflect light from the laser source;

a Fabry-Perot filter cavity to receive the reflected light;

at least one movable Fabry-Perot filter cavity mirror associated with said Fabry-Perot filter cavity;

a comb drive actuator coupled to said at least one movable mirror, wherein said comb drive actuator includes a set of movable fingers and a set of anchored fingers;

said set of movable fingers or said set of anchored fingers having a first finger, wherein a surface of said first finger has at least one of;

(i) a saw-tooth profile and (ii) a reverse saw-tooth profile;

a detector to detect photons exiting said Fabry-Perot filter cavity over time as said at least one movable mirror is moved by said comb drive actuator; and

a decision unit to determine if the analyte sample is associated with at least one type of molecule based on the sensed photons.

17. The spectrometer of claim 16, wherein said spectrometer comprises at least one of:

(i) a Raman device, (ii) an infra-red absorption device, and (iii) a fluorescence spectroscopy device.

18. The spectrometer of claim 16, wherein said comb drive actuator is associated with a first latched position and a second latched position.

19. A micro-electrical mechanical system apparatus, comprising:

a comb drive actuator driven by a voltage, wherein said comb drive actuator includes a set of movable fingers and a set of anchored fingers;

said set of movable fingers or said set of anchored fingers having a first finger, wherein a first surface of said first finger has at least one of;

(i) a saw-tooth profile and (ii) a reverse saw-tooth profile;

and at least one movable Fabry-Perot filter cavity mirror coupled to said comb drive actuator, wherein a relationship between the voltage and an amount of displacement associated with said at least one movable mirror is substantially linear.

20. The micro-electrical mechanical system apparatus of claim 19, wherein said set of movable fingers or said set of anchored fingers further comprises a second finger, wherein a first surface of said second finger has at least one of:

(i) a saw-tooth profile and (ii) a reverse saw-tooth profile, and a third finger positioned between said first finger and said second finger.