Interferometer element, spectrometer and method for operating an interferometer

Patent metadata

Field	Value
Publication number	US-11754445-B2
Application number	US-201917277642-A
Country	US
Kind code	B2
Filing date	Oct 22, 2019
Priority date	Oct 22, 2018
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

The disclosure relates to an interferometer element for use in a spectrometer which includes a micromechanical Fabry-Perot filter element, which has at least a first mirror element, a second mirror element, and a third mirror element. Each of the first mirror element, the second mirror element, and the third mirror element are arranged in series in an optical path of the interferometer element, and at least one of a first distance between the first and second mirror elements, and a second distance between the second and third mirror elements is modifiable.

First claim

The invention claimed is:

1. An interferometer element for use in a spectrometer, comprising:
a micromechanical Fabry-Perot filter element, which has at least a first mirror element, a second mirror element, and a third mirror element, wherein
each of the first mirror element, the second mirror element, and the third mirror element are arranged in series in an optical path of the interferometer element,
at least one of a first distance between the first and second mirror elements, and a second distance between the second and third mirror elements is modifiable,
the first, second, and third mirror elements are supported by respective suspensions, and
each of spring tensions or spring elasticities of the respective suspensions of the first, second, and third mirror element of the micromechanical Fabry-Perot filter element differ from each of the spring tensions or spring elasticities of the other of the respective suspensions of the first, second, and third mirror element.

2. The interferometer element as claimed in claim 1 , in which at least one of a first material of the first mirror element differs from a second material of the second mirror element such that the first mirror element and the second mirror element have different dispersions of a phase jump during a first reflection, and the second material of the second mirror element differs from a third material of the third mirror element, such that the second mirror element and the third mirror element have different dispersions of a phase jump during a second reflection.

3. The interferometer element as claimed in claim 2 , in which at least one of the first, second, and third material is a metallic or metal-containing material, and differs with respect to the refractive index from the other of the first, second, and third material.

4. The interferometer element as claimed in claim 1 , further comprising:
a control unit configured to electrically control modification of the at least one of the first and second distance, wherein the control unit is configured to cyclically repeat the modification of the at least one of the first and second distance.

5. The interferometer element as claimed in claim 4 , in which the control unit is configured to modify the at least one of the first and second distance at least one of electrostatically, piezoelectrically, and magnetically.

6. The interferometer element as claimed in claim 4 , in which the control unit is configured to modify the at least one of the first and second distance in response to a read distance signal, wherein at least one of the read distance signal represents at least one of a current first and a second distance, and the control unit is configured to set a maximum transmission of light through the micromechanical Fabry-Perot filter element by way of the modification.

7. The interferometer element as claimed in claim 1 , in which the micromechanical Fabry-Perot filter element is designed such that an object that is examined using the interferometer element is positioned between at least one of the first and second mirror element, and between the second and third mirror element.

8. The interferometer element as claimed in claim 1 , further comprising:
a spectral filter element configured to at least one of attenuate, and block a transmission of light of a predetermined wavelength range through the interferometer element.

9. The interferometer element as claimed in claim 1 , further comprising:
at least a fourth mirror element, which is arranged in the optical path in series with respect to the first, second, and third mirror elements, and wherein a third distance between the third and fourth mirror elements is modifiable.

10. A spectrometer comprising:
an interferometer element including
a micromechanical Fabry-Perot filter element, which has at least a first mirror element, a second mirror element, and a third mirror element, wherein
each of the first mirror element, the second mirror element, and the third mirror element are arranged in series in an optical path of the interferometer element,
at least one of a first distance between the first and second mirror elements, and a second distance between the second and third mirror elements is modifiable,
the first, second, and third mirror elements are supported by respective suspensions, and
each of spring tensions or spring elasticities of the respective suspensions of the first, second, and third mirror element of the micromechanical Fabry-Perot filter element differ from each of the spring tensions or spring elasticities of the other of the respective suspensions of the first, second, and third mirror element;

a light source configured to provide a light beam through the interferometer element; and
a detector configured to capture output light emerging from the spectrometer.

11. The spectrometer as claimed in claim 10 , in which the detector has a plurality of detector elements are at least one of configured for light of different wavelength ranges, and in which the light source is designed for the non-modulatable output of light.

12. A method for operating an interferometer comprising:
providing an interferometer element including
a micromechanical Fabry-Perot filter element, which has at least a first mirror element, a second mirror element, and a third mirror element, wherein
each of the first mirror element, the second mirror element, and the third mirror element are arranged in series in an optical path of the interferometer element, and
at least one of a first distance between the first and second mirror elements, and a second distance between the second and third mirror elements is modifiable,
the first, second, and third mirror elements are supported by respective suspensions, and
each of spring tensions or spring elasticities of the respective suspensions of the first, second, and third mirror element of the micromechanical Fabry-Perot filter element differ from each of the spring tensions or spring elasticities of the other of the respective suspensions of the first, second, and third mirror element;

modifying at least one of the first distance and the second distance to obtain output light; and
at least one of detecting, and analyzing output light emerging from the interferometer element.

13. The method as claimed in claim 12 , wherein modifying the at least one of the first distance and the second distance and the at least one of detecting and analyzing the output light is controlled by executing a computer program.

14. The method as claimed in claim 13 , wherein the computer program is stored on a machine readable storage medium.

Assignees

• Bosch Gmbh Robert

Inventors

• Noltemeyer Ralf
• Stein Benedikt
• Huber Christian
• Schelling Christoph
• Kraemmer Christoph Daniel
• Roedel Reinhold

Classifications

• G01J3/0208 Primary

  using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction · CPC title

• G01J3/027 Primary

  Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation · CPC title

• G01J3/26

  using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters · CPC title

• G01J3/30

  Measuring the intensity of spectral lines directly on the spectrum itself (G01J3/42, G01J3/44 take precedence) · CPC title

• G01J3/4535

  Devices with moving mirror (G01J3/4532 takes precedence) · CPC title