MEMS device for interferometric spectroscopy
The present application relates to a system for performing time-resolved interferometric spectroscopy of incoming light. In some embodiments, the system includes one or more optical elements, a photo-detector, a capacitance detector, and one or more processors. Upon application of a varying input signal to the one or more optical elements, a change to an optical characteristic is caused resulting in a changing interference pattern produced by the incoming light incident on the one or more optical elements. During the application of the varying input signal, the photo-detector may detect an intensity of light output from the one or more optical elements and the capacitance detector may detect a capacitance of the one or more optical elements.
1. A micro electro-mechanical (MEMS) apparatus for operating upon electromagnetic radiation incident thereon, to create an altered electromagnetic radiation beam upon transmission therethrough, the apparatus receiving varying electrical input signals and at least one measurement input signal, and comprising:
a Fabry-Perot etalon that includes a pair of multi-layer partially reflective, partially transmissive plates disposed parallel to one another and spaced with a first gap distance that includes an air-gap, wherein the first gap distance has a first predetermined distance in an initial plate position;
a pair of electrodes, each of the pair of electrodes being mechanically coupled to one of the multi-layer partially reflective, partially transmissible plates, wherein the pair of electrodes are disposed parallel to one another and spaced with a second gap distance, wherein the second gap distance has a second predetermined distance in an initial electrode position;
wherein each of the pair of electrodes are ring-shaped electrodes, and the electromagnetic radiation incident on the Fabry-Perot etalon strikes the Fabry-Perot etalon at an area interior to the ring-shaped electrodes;
where each of the pair of ring-shaped electrodes is comprised of three independent components;
wherein the second predetermined distance is greater than the first predetermined distance by an amount that is at least one applied layer of one of the pair of multi-layer partially reflective, partially transmissive plates;
wherein upon application of one of the varying electrical input signals to each of the three independent components of the pair of electrodes of the MEMS apparatus, a varying first gap distance results between the pair of multi-layer partially reflective, partially transmissive plates of the Fabry-Perot etalon that is smaller than a varying second gap distance between the pair of electrodes, thereby causing the electromagnetic radiation incident on the Fabry-Perot etalon to change characteristics upon passing through the pair of multi-layer partially reflective, partially transmissive plates and result in the altered electromagnetic radiation beam; and
wherein a measurement signal is obtained from the MEMS apparatus across the pair of electrodes or across the pair of multi-layer partially reflective, partially transmissive plates or a pair comprising one of the pair of electrodes and one of the pair of multi-layer partially reflective, partially transmissive plates.
2. The apparatus according to claim 1 , wherein the at least one applied layer is non-conductive and that is mechanically coupled to a top one of the pair of electrodes.
3. The apparatus according to claim 2 , wherein the measurement signal is taken across the pair of electrodes.
4. The apparatus according to claim 2 , wherein the at least one applied layer is within a top one of the pair of multi-layer partially reflective, partially transmissive plates, and each of the pair of multi-layer partially reflective, partially transmissive plates has an inner layer that is a conductive transparent material.
5. The apparatus according to claim 4 , wherein the measurement signal is taken across the inner layer of each of the pair of multi-layer partially reflective, partially transmissive plates.
6. The apparatus according to claim 4 , wherein the apparatus is made on a chip, and
a width of the chip is less than or equal to 10 millimeters (mm);
a length of the chip is less than or equal to 10 mm; and
a height of the chip is less than or equal to 5 mm.
7. The apparatus according to claim 4 , wherein the first predetermined distance is in the range of 5,000-10,000 Angstroms.
8. The apparatus according to claim 4 , wherein the MEMS apparatus operates in at least one of the visible spectrum, the infrared spectrum and the ultraviolet spectrum.
9. The apparatus according to claim 4 , wherein the MEMS apparatus operates in the visible spectrum, the infrared spectrum and the ultraviolet spectrum.
10. The apparatus of claim 2 , wherein:
each of the pair of multi-layer partially reflective, partially transmissive plates include:
glass, which glass for one of the pair of multi-layer partially reflective, partially transmissive plates is the at least one applied layer that is nonconductive; and
a conducting film or dielectric film disposed on an inner surface of each of the glass, thereby providing for the partially transmissive and the partially reflective aspects of each of the pair of multi-layer partially reflective, partially transmissive plates.
11. The apparatus of claim 10 , wherein the conducting film is disposed on the inner surface of each of the glass.
12. The apparatus of claim 11 , wherein the pair of multi-layer partially reflective, partially transmissive plates are identified as a first plate and a second plate, wherein the first plate is affixed to a substrate and the second plate is disposed above the first plate at the first predetermined distance;
the varying input signal comprises a first electrical voltage signal applied to the pair of electrodes, wherein application of the first electrical voltage signal causes the second plate to deform from the initial plate position, thereby decreasing the first gap from the first predetermined distance to a second distance; and
wherein measurement signal is obtained as one or more of a capacitance, a voltage, or a current.
13. The apparatus of claim 12 , wherein the first predetermined distance is between 500 Angstroms and 1 micron.
14. The apparatus of claim 11 , wherein upon application of the varying electrical input signal to the pair of electrodes of the MEMS apparatus, the varying first gap distance results between the pair of multi-layer partially reflective, partially transmissive plates of the Fabry-Perot etalon as a result of a deflection of the first plate, deflection of the second plate, or deflection of the first plate and the second plate; and the Fabry-Perot etalon functions as a parallel plate capacitor that provides an instantaneous mutual capacitance.
15. The apparatus of claim 10 , wherein the each of the pair of electrodes are disposed on a surface of each of the glass associated with each of the pair of multi-layer partially reflective, partially transmissive plates, respectively.