Optical microphone and method using the same
View Patent ↗An optical microphone comprises a light source configured to emit a light beam and an acoustic sensor configured to reflect the light beam. The acoustic sensor includes single-wall nanotubes and deflects in response to pressure waves. An optional reflector of the optical microphone is configured to re-reflect the light beam from the acoustic sensor. A detector is configured to detect the light beam from the acoustic sensor or the reflector, and thus measures the pressure waves.
1. An optical microphone, comprising:
a light source configured to emit a light beam, and
an acoustic sensor including single-wall nanotubes, wherein the acoustic sensor deflects in response to pressure waves and is configured to reflect the light beam emitted from the light source and impinged on the single-wall nanotubes.
2. The optical microphone of claim 1 , further comprising a detector configured to detect the light beam reflected by the acoustic sensor.
3. The optical microphone of claim 1 , further comprising a reflector including multi-wall nanotubes and configured to re-reflect the light beam from the acoustic sensor.
4. The optical microphone of claim 3 , further comprising a detector configured to detect the light beam from the reflector.
5. The optical microphone of claim 3 , wherein the reflector is a membrane reflector on which multi-wall nanotubes are randomly disposed.
6. The optical microphone of claim 1 , wherein the light beam from the light source is illuminated onto the sidewalls of the single-wall nanotubes.
7. The optical microphone of claim 1 , wherein the light source is a laser.
8. The optical microphone of claim 1 , further comprising a polarizer configured to polarize the light beam emitted from the light source.
9. The optical microphone of claim 1 , wherein the acoustic sensor further includes a base substrate, the single-wall nanotubes being disposed on the base substrate such that the nanotube axes of the single-wall nanotubes are perpendicular to the substrate surface.
10. The optical microphone of claim 1 , further comprising a housing in which the light source and the acoustic sensor are contained.
11. The optical microphone of claim 10 , wherein the housing includes an inner wall composed of single-wall nanotubes.
12. The optical microphone of claim 10 , wherein the housing includes a protection element disposed in proximity to the acoustic sensor for protecting the acoustic sensor from impurities.
13. The optical microphone of claim 1 , wherein the acoustic sensor includes parallel-aligned single-wall nanotubes.
14. The optical microphone of claim 13 , wherein the acoustic sensor includes an array of parallel-aligned single-wall nanotubes.
15. A method for detecting acoustic pressure waves, comprising:
emitting a light beam, and
using an acoustic sensor including single-wall nanotubes to reflect the emitted light beam impinged on the single-wall nanotubes, wherein the acoustic sensor deflects in response to pressure waves.
16. The method of claim 15 , further comprising:
using a reflector to re-reflect the light beam from the acoustic sensor, and
detecting the re-reflected light beam from the reflector.
17. The method of claim 15 , wherein the acoustic sensor includes parallel-aligned single-wall nanotubes.