Optical pressure-sensing system and method for sensing pressure

• US 20060144150A1
• Filed: 01/03/2005
• Published: 07/06/2006
• Est. Priority Date: 01/03/2005
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Wu, Jeah Sheng
• Granted Patent: US 7,104,135 B2
• Time in Patent Office: Days
• US Class Current: 73/705
• CPC Class Codes: G01L 11/02 by optical means

Abstract

The optical pressure-sensing system essentially comprises a light source, a resonant cavity and a detector, where the light source is used for generating a light with a predetermined wavelength, the resonant cavity includes a stationary wall with a stationary plane and a movable wall with a movable plane, and the detector is used for detecting a resonated light generated in the resonant cavity by resonating the light between the stationary plane and the movable plane. According to the present invention, a first light is generated and resonated in a resonant cavity to amplify the interaction between the first light and gas molecules in the resonated cavity. The interaction is measured, and the pressure in the resonant cavity is calculated based on the interaction. The interaction between the light and gas molecules in the resonant cavity may change the polarization angle or the phase of the light.

Claims

1. An optical pressure-sensing system, comprising:

a light source for generating a light with a predetermined wavelength;

a resonant cavity comprising two planes for generating a resonated light by resonating the light between the two planes; and

a detector for detecting the resonated light.

2. The optical pressure-sensing system of claim 1, further comprising a first polarizer positioned between the light source and the resonant cavity, the detector being a second polarizer for measuring the polarization angle of the resonated light.

3. The optical pressure-sensing system of claim 1, further comprising a first splitter positioned between the light source and the resonant cavity, the detector being a second splitter for measuring the phase retardation of the resonated light.

4. The optical pressure-sensing system of claim 1, further comprising a magnetic field generator for applying a magnetic field to the resonant cavity.

5. The optical pressure-sensing system of claim 1, further comprising an electric field generator for applying an electric field to the resonant cavity.

6. A method for sensing pressure, comprising steps of:

generating a first light;

resonating the first light in a resonant cavity to amplify the interaction between the first light and gas molecules in the resonant cavity to generate a resonated light.

detecting the interaction; and

calculating the pressure in the resonant cavity based on the interaction.

7. The method for sensing pressure of claim 6, wherein the first light is a polarized light with a first polarization angle.

8. The method for sensing pressure of claim 7, wherein the interaction between the first light and gas molecules in the resonant cavity transforms the first light with the first polarization angle into the resonated light with a second polarization angle.

9. The method for sensing pressure of claim 8, wherein the step of detecting the interaction is to measure the difference between the first polarization angle and the second polarization angle.

10. The method for sensing pressure of claim 9 wherein the step of calculating the pressure in the resonant cavity based on the interaction comprises steps of:

calculating the density of gas molecules in the resonant cavity based on the difference; and

calculating the pressure in the resonant cavity based on the density of gas molecules in the resonant cavity.

11. The method for sensing pressure of claim 6, wherein the step of generating a first light comprises steps of:

generating an original light; and

splitting the original light into the first light and a second light, wherein the first light enters the resonant cavity and the second light bypasses the resonant cavity.

12. The method for sensing pressure of claim 6, wherein the interaction between the first light and gas molecules in the resonant cavity transforms the first light with a first phase into the resonated light with a second phase.

13. The method for sensing pressure of claim 12, wherein the step of detecting the interaction is to measure the phase difference between the first phase and the second phase.

14. The method for sensing pressure of claim 13, wherein the step of calculating the pressure in the resonant cavity based on the interaction comprises steps of:

calculating the density of gas molecules in the resonant cavity based on the phase difference; and

calculating the pressure in the resonant cavity based on the density of gas molecules in the resonant cavity.

15. The method for sensing pressure of claim 6, further comprising a step of applying an electric field to the resonant cavity.

16. The method for sensing pressure of claim 6, further comprising a step of applying a magnetic field to the resonant cavity.