EP0014848A2
Expired / Lapsed
EP
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Method and apparatus for an optical sensor utilizing semiconductor filters
Assignee: Boeing North American Inc
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Filing: 1980-01-22
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Granted: —
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Expires: 2000-01-22
Abstract
Abstract a method and resulting apparatus for implementing a unique optical sensor that is adapted to be interfaced with a low cost, compact fiber-optic transmission system to provide an accurate indication of a sensed physical parameter (e.g. temperature) of a remote sample. The sensor is fabricated so as to include a semiconductor material that has optical-wavelength-dependent filter characteristics that may be varied as a function of a physical parameter such astemperature. In one embodiment, a graded optical filter fabricated by using thin-film deposition techniques on an amorphous semiconductor material, provides position responsive high-pass filter characteristics. Such filter characteristics are then utilized by moving a light source as a function of a physical parameter and generating an optical signal therefrom having a cutoff frequency dependent upon the position of the light source. In another embodiment, the temperature dependent frequency cutoff characteristics in the absorption edge of amorphous selenium, are utilized more directly in an optical temperature sensor. The optical utilization of amorphous semiconductor material is a particularly advantageous feature of the invention in reducing the cost and complexity of semiconductor optical filters.
Inventors
- 👤 Kenneth Allan James
- 👤 William Henry Quick
- 👤 Virgil Haskell Strahan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 08:14
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/268; G01K; G01K11/00; G01K11/12; G01K11/14; G02; G02B; G02B5/00; G02B5/20; G02B5/207
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
152 words
A method for fabricating a sensor for use in an optical sensor system that utilizes a position variable light beam for sensing the status of a physical parameter and a transmission means for reporting the status to a detector, the method comprising the steps of: 1. selecting a semiconductor material having optical wavelength cutoff characteristics at the edge of the absorption band, which vary with annealing temperature, 2. annealing a region of said semiconductor material at a selected annealing temperature, 3. repeating step 2 hereof for additional regions of semiconductor material and modifying the annealing temperature for each such additional region relative to the annealing temperature of the previous region, and 4. selecting an annealing temperature for each said region to provide a contiguous composite of such regions which, in combination, provide an optical filter having a wavelength cutoff characteristic that varies with position of said light beam relative to said filter.
Claim 2
Independent Claim
152 words
A method for fabricating a sensor for use in an optical sensor system that utilizes a position variable light beam for sensing the status of a physical parameter and a transmission means for reporting the status to a detector, the method comprising the steps of: 1. selecting a semiconductor material having optical wavelength cutoff characteristics at the edge of the absorption band, which vary with annealing temperature, 2. annealing a region of said semiconductor material at a selected annealing temperature, 3. repeating step 2 hereof for additional regions of semiconductor material and modifying the annealing temperature for each such additional region relative to the annealing temperature of the previous region, and 4. selecting an annealing temperature for each said region to provide a contiguous composite of such regions which, in combination, provide an optical filter having a wavelength cutoff characteristic that varies with position of said light beam relative to said filter.
Claim 3
Dependent Claim
17 words
The method of fabricating a sensor as defined in Claim 1, wherein said semiconductor material is germanium.
Claim 4
Dependent Claim
20 words
The method of fabricating a sensor as defined in Claim 2,wherein said germanium semiconductor material is in an amorphous state.
Claim 5
Dependent Claim
28 words
The method of fabricating a sensor as defined in Claim 1, comprising the additional step of depositing each said region as a thin film in an amorphous state.
Claim 6
Independent Claim
36 words
An apparatus for filtering light energy comprising: a plurality of regions of semiconductor material, each such region having wavelength cutoff characteristics that differ from the wavelength cutoff characteristics of the regions to which it is contiguous.
Claim 7
Independent Claim
36 words
An apparatus for filtering light energy comprising: a plurality of regions of semiconductor material, each such region having wavelength cutoff characteristics that differ from the wavelength cutoff characteristics of the regions to which it is contiguous.
Claim 8
Dependent Claim
27 words
The apparatus for filtering light energy as defined in Claim 5, wherein the wavelength cutoff characteristic of said semiconductor material is dependent upon its fabrication annealing temperature.
Claim 9
Dependent Claim
20 words
The apparatus for filtering light energy as defined in Claim 6, wherein said semiconductor material is in an amorphous state.
Claim 10
Dependent Claim
17 words
The apparatus for filtering light energy as defined in Claim 6, wherein said semiconductor material is germanium.
Claim 11
Independent Claim
115 words
An apparatus for sensing the status of a physical parameter and for reporting such status to a detector, the apparatus comprising: a. means for positioning a braodband light source in response to said status, b. a graded optical filter having a light wavelength cutoff characteristic that varies as a function of the position of a light source relative to said filter, c. means for applying said light source to said filter, d. means for collecting light energy from said light source that passes through said filter, and e. means for applying said collected light energy to a detector, the output signal of said detector being responsive to the cutoff wavelength of said collected light energy.
Claim 12
Independent Claim
115 words
An apparatus for sensing the status of a physical parameter and for reporting such status to a detector, the apparatus comprising: a. means for positioning a braodband light source in response to said status, b. a graded optical filter having a light wavelength cutoff characteristic that varies as a function of the position of a light source relative to said filter, c. means for applying said light source to said filter, d. means for collecting light energy from said light source that passes through said filter, and e. means for applying said collected light energy to a detector, the output signal of said detector being responsive to the cutoff wavelength of said collected light energy.
Claim 13
Dependent Claim
55 words
1 0 . The apparatus for sensing the status of a physical parameter as defined in Claim 9, wherein said graded optical filter comprises a plurality of contiguous regions of semiconductor material, each such region having a wavelength cutoff characteristic that differs from the wavelength cutoff characteristic of the regions to which it is contiguous.
Claim 14
Dependent Claim
31 words
The apparatus for sensing the status of a physical parameter as defined in Claim 10, wherein the wavelength cutoff characteristic of said semiconductor material is dependent upon its fabrication annealing temperature.
Claim 15
Dependent Claim
24 words
The apparatus for sensing the status of a physical parameter as defined in Claim 11, wherein said semiconductor material is in an amorphous state.
Claim 16
Dependent Claim
21 words
The apparatus for sensing the status of a physical parameter as defined in Claim 11, wherein said semiconductor material is germanium.
Claim 17
Independent Claim
21 words
An apparatus for filtering light energy comprising a semiconductor material having a wavelength cutoff characteristic that is a function of temperature.
Claim 18
Independent Claim
21 words
An apparatus for filtering light energy comprising a semiconductor material having a wavelength cutoff characteristic that is a function of temperature.
Claim 19
Dependent Claim
20 words
The apparatus for filtering light energy as defined in Claim 14, wherein the semiconductor material is in an amorphous state.
Claim 20
Dependent Claim
17 words
The apparatus for filtering light energy as defined in Claim 14, wherein said semiconductor material is selenium.
Claim 21
Independent Claim
96 words
An apparatus for sensing the temperature of a remote sample and reporting such temperature to a detector, the apparatus comprising: a. a broadband light source, b. an optical filter having a light wavelength cutoff characteristic that varies as a function of temperature, c. means for applying said light source to said filter, d. means for collecting light energy from said light source that passes through said filter, and e. means for applying said collected light energy to a detector, the outpout signal of said detector being responsive to the cutoff wavelength of said collected light energy.
Claim 22
Independent Claim
96 words
An apparatus for sensing the temperature of a remote sample and reporting such temperature to a detector, the apparatus comprising: a. a broadband light source, b. an optical filter having a light wavelength cutoff characteristic that varies as a function of temperature, c. means for applying said light source to said filter, d. means for collecting light energy from said light source that passes through said filter, and e. means for applying said collected light energy to a detector, the outpout signal of said detector being responsive to the cutoff wavelength of said collected light energy.
Claim 23
Dependent Claim
23 words
The apparatus for sensing the temperature of a remote sample as defined in Claim 17, wherein said optical filter comprises a semiconductor material.
Claim 24
Dependent Claim
24 words
The apparatus for sensing the temperature of a remote sample as defined in Claim 18, wherein said semiconductor material is in an amorphous state.
Claim 25
Dependent Claim
21 words
The apparatus for sensing the temperature of a remote sample as defined in Claim 18, wherein said semiconductor material is selenium.
References Cited (Backward Citations)
No citation records indexed.
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