Mirror based micromechanical systems and methods
Unlike most MEMS device configurations which simply switch between two positions in many optical devices the state of a MEMS mirror is important in all transition positions. It may determine the characteristics of an optical delay line system and by that an optical coherence tomography system in one application and in another the number of wavelength channels and the dynamic wavelength switching capabilities in the other. The role of the MEMS is essential and it is responsible for altering the paths of the different wavelengths in either device. It would be beneficial to improve the performance of such MEMS and thereby the performance of the optical components and optical systems they form part of. The inventors have established improvements to the design and implementation of such MEMS mirrors as well as optical waveguide technologies to in-plane optical processing as well as the mid infrared for optical spectroscopy.
1. A device comprising:
a rotatable microelectromechanical system (R-MEMS), the R-MEMS having at least a front surface and a back surface;
a translational microelectromechanical actuator coupled to the R-MEMS;
a planar waveguide supported by the R-MEMS and having a first surface disposed proximate the front surface of the R-MEMS and a second surface disposed proximate the rear surface of the R-MEMS; and
an optical circuit disposed adjacent to the R-MEMS and planar waveguide having a coupling surface having a profile matching the first surface, wherein
the R-MEMS does not form a predetermined portion of the planar waveguide; and
the translational microelectromechanical actuator adjusts the size of a gap between the front surface of the R-MEMS and the coupling surface of the optical circuit.
2. The device according to claim 1 , wherein
an optical signal propagating within the optical circuit propagates from the optical circuit into the planar waveguide via the coupling surface and first surface, reflects from the second surface of the planar waveguide, and is coupled back into the optical circuit via the front surface and the coupling surface.
3. The device according to claim 1 , wherein
the optical circuit comprises a planar waveguide, the first surface, the second surface and coupling surface are predetermined portions of circles;
the first surface and coupling surface have correlated center points for the circles they are predetermined portions of; and
the pivot point or flexible anchor of the R-MEMS is aligned with the common center point.
4. The device according to claim 1 , wherein
the first surface and coupling surface are predetermined portions of circles and are each anti-reflection coated;
the second surface forms part of a mirror having a predetermined profile for optical signals propagating within the planar waveguide; and
the body of the R-MEMS rotates the planar waveguide such that the first surface rotates relative to the coupling surface.
5. The device according to claim 1 , wherein
the first surface and coupling surface are predetermined portions of circles;
the second surface forms part of a reflector having a predetermined profile for optical signals propagating within the planar waveguide; wherein
the reflector is selected from the group comprising a planar mirror, a parabolic mirror, a curved mirror, and a reflective dispersive element.
6. The device according to claim 1 , wherein
the optical circuit comprises a plurality of optical waveguides;
the first surface and coupling surface are predetermined portions of circles;
the second surface forms part of a reflector having a predetermined profile for optical signals propagating within the planar waveguide having a focus distal to the second surface; and
an end of each optical waveguide of the plurality of optical waveguides is disposed at a predetermined position within the optical circuit established in dependence upon the path of the focus as the R-MEMS rotates.
7. The device according to claim 6 , wherein
at least one of:
a predetermined portion of the plurality of optical waveguides comprise a passive waveguide region and an optical filter, each individual optical filter having a predetermined wavelength transfer characteristic; and
that portion of the optical circuit between the first surface and the ends of the plurality of optical waveguides is a planar waveguide.
8. The device according to claim 1 , further comprising
a pivot point or flexible anchor coupled at a predetermined point to the R-MEMS;
a microelectromechanical element comprising a predetermined portion of the R-MEMS distal to the pivot point or flexible anchor and performing rotation around the pivot point or flexible anchor under actuation; and
an anchor spring attached to a predetermined portion of the microelectromechanical element, wherein the anchor spring engages against a predetermined portion of the R-MEMS once the microelectromechanical element has rotated a predetermined angle in order to counter a pull-in effect of the R-MEMS and microelectromechanical element.
9. The device according to claim 8 , wherein
the anchor spring increases the elastic nature of the microelectromechanical element once the predetermined angle has been reached.
10. The device according to claim 1 , wherein
the R-MEMS is coupled via a pivot or flexible anchor to a rotational microelectromechanical actuator for rotating the R-MEMS; and
the rotational microelectromechanical actuator has disposed upon it distal to the side coupled to the rotational microelectromechanical actuator teeth for engaging corresponding teeth upon another portion of the device, wherein the teeth engage the corresponding teeth in order to lock the rotation angle of the R-MEMS.
11. The device according to claim 1 , wherein
the R-MEMS has disposed upon it teeth for engaging corresponding teeth upon another portion of the device, wherein the teeth engage the corresponding teeth in order to lock the rotation angle of the R-MEMS; and
the corresponding teeth are engaged/disengaged with the teeth under the action of another linear translational microelectromechanical actuator.
12. A device comprising:
a rotatable microelectromechanical system (R-MEMS), the R-MEMS having at least a front surface and a back surface;
a translational microelectromechanical actuator coupled to the R-MEMS;
a planar waveguide supported by the R-MEMS and having a first surface disposed proximate the front surface of the R-MEMS and a second surface disposed proximate the rear surface of the R-MEMS; and
an optical circuit disposed adjacent to the R-MEMS and planar waveguide having a coupling surface having a profile matching the first surface, wherein
the R-MEMS does not form a predetermined portion of the planar waveguide;
the R-MEMS is coupled via a pivot or flexible anchor to a non-movable portion of the device;
a rotational microelectromechanical actuator is coupled to the R-MEMS for rotating the R-MEMS; and
the rotational microelectromechanical actuator has disposed upon it distal to the side coupled to the rotational microelectromechanical actuator teeth for engaging corresponding teeth upon another portion of the device, wherein the teeth engage the corresponding teeth in order to lock the rotation angle of the R-MEMS.
13. The device according to claim 12 , wherein
the linear translational microelectromechanical actuator adjusts the size of a gap between the front surface of the R-MEMS and the coupling surface of the optical circuit.
14. The device according to claim 12 , wherein
the corresponding teeth are engaged/disengaged with the rotational microelectromechanical actuator teeth under the action of a second linear translational microelectromechanical actuator.
15. The device according to claim 12 , wherein
the second surface of the planar waveguide is a reflective grating.
16. The device according to claim 12 , further comprising
a pivot point or flexible anchor coupled at a predetermined point to the R-MEMS;
a microelectromechanical element comprising a predetermined portion of the R-MEMS distal to the pivot point or flexible anchor and performing rotation around the pivot point or flexible anchor under actuation; and
an anchor spring attached to a predetermined portion of the microelectromechanical element, wherein the anchor spring engages against a predetermined portion of the R-MEMS once the microelectromechanical element has rotated a predetermined angle in order to counter a pull-in effect of the R-MEMS and microelectromechanical element.
17. The device according to claim 16 , wherein
the anchor spring increases the elastic nature of the microelectromechanical element once the predetermined angle has been reached.
18. A device comprising:
a rotatable microelectromechanical system (R-MEMS), the R-MEMS having at least a front surface and a back surface;
a first translational microelectromechanical actuator coupled to the R-MEMS;
a planar waveguide supported by the R-MEMS and having a first surface disposed proximate the front surface of the R-MEMS and a second surface disposed proximate the rear surface of the R-MEMS;
a flexible anchor coupled to a predetermined point on the R-MEMS; and
an optical circuit disposed adjacent to the R-MEMS and planar waveguide having a coupling surface having a profile matching the first surface, wherein
the R-MEMS does not form a predetermined portion of the planar waveguide; and
first teeth are engaged and disengaged with second teeth under the action of a second translational microelectromechanical actuator to lock and unlock the R-MEMS.
19. The device according to claim 18 , wherein
the first translational microelectromechanical actuator adjusts the size of a gap between the front surface of the R-MEMS and the coupling surface of the optical circuit.
20. The device according to claim 18 , wherein
the R-MEMS further comprises a rotational microelectromechanical actuator coupled to the flexible anchor for rotating the R-MEMS.