CA2084152A1 - Optical apparatus - Google Patents
Optical apparatusInfo
- Publication number
- CA2084152A1 CA2084152A1 CA002084152A CA2084152A CA2084152A1 CA 2084152 A1 CA2084152 A1 CA 2084152A1 CA 002084152 A CA002084152 A CA 002084152A CA 2084152 A CA2084152 A CA 2084152A CA 2084152 A1 CA2084152 A1 CA 2084152A1
- Authority
- CA
- Canada
- Prior art keywords
- optical
- detector
- fibers
- light
- optical apparatus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
- G01N21/4738—Diffuse reflection, e.g. also for testing fluids, fibrous materials
- G01N21/474—Details of optical heads therefor, e.g. using optical fibres
Abstract
ABSTRACT OF THE DISCLOSURE
Optical apparatus having an optical fiber to receive light incident thereon at one end, and a detector located adjacent the other end of the optical fiber to receive light passing through the optical fiber and emitting from the other end thereof to be incident on the detector for analysis purposes.
Optical apparatus having an optical fiber to receive light incident thereon at one end, and a detector located adjacent the other end of the optical fiber to receive light passing through the optical fiber and emitting from the other end thereof to be incident on the detector for analysis purposes.
Description
- l- 20841~2 This invention relates to optical apparatus and particularly to optical apparatus for receiving scattered light.
Transmissometers and scattering meters need to measure light at very low levels with reliability and reproducibility. Parasitic liqht, produced by scattering off optical surfaces or the dust on them, must be kept to a minimum and must not change with time in order that its effect may be subtracted accurately from the received signal. Unfortunately, the collecting optics for such apparatus are comple~ and generally involve many optical surfaces which are difficult to clean and align. This results in a large parasitic signal.
Standard optics, because of their rigid geometric disposition re~uirements, take up a lot of space which forces the overall device to be larger. This is merely annoying in an instrument designed for the laboratory.
However, for an instrument designed to perform measurements in the field, too large a size may completely preclude or at best severely curtail its use.
In order to improve the situation, apparatus has previously been designed wherein the received beam is separated into several beams by a set of beam~splitters arranged in series. At the focus of each beam an optical mask is inserted. The optical mask for the direct transmission channel has a hole of small diameter at its center. The various scattered channels have rings cut out of them. The outer and inner diameters of the rings define the acceptance angles for the scattered light. The angles ~ are related to the diameters D by the following formula:
= D
where F is the focal length of the primary lens of the receiver. The light transmitted by each mask is then :
. ,. , ........................ ~ ~
"".'1.,.','~..,~ .,, , i~ ,',~"-, ,,.j~"," ,~"~ ",,, ~, ~ .. . ,,~,",..",, ",~ " ~,",,,~
., . ' ' ;' ' ' ' :., ' ~ : ', : ' . '~
'- '. ' ' ' . : ' : ' . .
,:: , ' , , ': .' ` ' ~ . :
collected onto the detectors by short focal length lenses situated behind each mask. The lenses are disposed in such a way as to image the total entrance plane of the primary lens on the detectors.
In another prior art method, a special detector assembly is fabricated. This assembly consists of a set of ring detectors and a central circular detector. In this case, the angles of acceptance are related to the various inner and outer diameters of the detectors by the formula given above. The primary focusing lens and the face of the detector assembly are the only optical surfaces present in this method.
It has become apparent that the disadvantage of the first-mentioned prior art method is the large number of optical elements that have to be aligned precisely and then maintained in position rigidly even when the ? transmissometer-nephelometer is moved or bumped hard, as it will be in field use. The surfaces of these optical elements have to be cleaned carefully before any alignment and elaborate precautions have to be taken to snsure that they remain clean during and after the alignment. This is essential since the scattering of these surfaces will be , seen by the instrument and will considerably reduce its sensitivity and accuracy. For these reasons, maintenance of such a system is a complex undertaking.
In the second prior art method mentioned above, the limitations are principally due to electronic problems.
The optics are simple in this apparatus and involve only the primary focusing lens and the detector assembly. The first problem of an electronic nature is due to cross-talk between the various detectors. This means that some portion of the signal falling on a given detector will be seen by the others. Since the detectors of scattered light receive, in general, signals which are much smaller than the transmitted signal in the central detector of the array, they will be swamped by the induced cross-talk and :
~.
~ 208~152 their readings will be inaccurate. The second problem of an electronic nature is due to the noise inherent in the detectors. In forward-angle scattering the signal gets much weaker as the angle is increased and one would therefore like to collect it over as large an area as possible. However, if one increases the area of the detector the electronic noise increases as the square root of the area. The capacitances of the detector also increases as the area of the detector increases and this further increases the noise of the transimpedance amplifiers connected to them. The accuracy of the device is therefore severely compromised. This complication is avoided in the first prior art apparatus mentioned above but at the expense of using separate lenses to reduce the image of each ring with various magnifications onto detectors of the same size.
It is an object of the present invention to provide optical apparatus in which the above-mentioned disadvantages are reduced or substantially obviated.
According to the present invention there is provided optical apparatus including an optical fiber to receive light incident thereon at one end, and a detector located adjacent the other end of said optical fiber to receive light passing through said optical fiber and emitting from the other end thereof to be incident on said detector for analysis purposes.
According to one embodiment of the invention there is provided optical apparatus including a plurality of fibers, a plurality of detectors, said fibers being arranged in groups, and a respective detector being responsive to each group to provide an indication of the light from the respective group. The groups may comprise rings of optical fibers and each ring of optical fibers may be separated from the next by an absorbing spacer.
An embodiment of the present invention will now be described, by way of example, with reference to the 208~152 accompanying drawings in which:-Figure 1 is a diagrammatic representation ofapparatus according to the embodiment, and Figure 2 is a cross-sectional representation of a bundle of optical fibers in Figure 1.
Referring to Figure 1, scattered light is incident on an input lens 2 which coll~cts the scattered light and focuses it on the rings of optical fibers in a bundle 4.
A central circle 6 collects the light at the focus of the primary input lens 2. This is shown in Figures 1 and 2 as a central disk of fibers. Light absorbing spaces, such as 8, are provided in between the rings and these also serve as a retaining structure for the fiber rings. The numerical aperture of the fibers should be chosen to match the small f-number of the input lens, otherwise some collected light will be lost from the apparatus.
Referring to the cross-sectional view of the bundle in Figure 2, it will be seen that the groups of fibers are arranged in rings. Each ring of fibers forms a group 10, 12 or 14 which is brought out to a respective detector 16, 18 or 20. If the group size is smaller than the respective detector, then the end of the group can be simply fi~ed to the detector front face by any suitable means, as shown for detector 18. Care must also be used in order that the light emitted in the numerical aperture of the fibers does not overspill the detector active area and be lost to the apparatus. If the group size exceeds the detector size, then a short focal-length lens, aspheric in shape if need be, must be used to project the image of the fiber group onto the detector and reduce the image size to the size of the active area of the detector. Such a short focal-length lens is shown at 22 and 24.
To reduce the possibility of spurious scattering from the apparatus, the ends 26 and 28, lens 22 or 24 and adjacent respective detector 16 or 20 are held in place in - 5 _ 20841~2 a respective container 30 or 32. Each container 30 and 32 is sealed against contamination by dust and other aerosols. Assembly of these containers should be done, if possible, in a clean-room environment.
The fiber core to clad diamPter ratio should be as large as possible to ensure maximum light throughput in the fiber. The overall fiber size should be small enough so that the area of the respective scattering ring is filled uniformly. The required uniformity depends on the gradient of the scattering phase function. The phase function should not vary by more than 30% over an angular difference corresponding to the diameter of a single fiber.
For convenience in the above description, the composite assembly of fibers has been referred to as a bundle whereas each ring of fibers is identified as a group. In the art, each ring of fibers is sometimes referred to as a bundle. The composite assembly of rings may then be referred to as a cable.
It will be apparent that in the described embodiment, the use of fiber optic groups allows one to minimize the number of optical services in the received optics of transmissometers and scattering meters.
Furthermore, these optical surfaces can be cleaned once during the assembly of the apparatus and then sealed against any further contamination by dust or aerosols.
The same met~od also allows the use of physically separate detectors for each scattering or transmission channel.
This substantially prevents what is known in the art as eiectrical cross-talk from occurring. The susceptibility to parasitic scattering is reduced whilst the groups facilitate a greater flexibility in packaging the apparatus and ease considerably the optical alignment problem. The apparatus is also inherently more rugged and reliable.
Furthermore, the fiber groups permit the use of separate detectors for the transmitted channel and each of the scattering channels. Each detector can thus be optimized separately in terms of signal to noise or speed of response. The detectors are not subject to the problem of cross-talk. A signal from one channel cannot influence the other channels to a great extent.
The optical apparatus has been described as being for transmissometers and scattering meters. It will be understood that the invention is not limited thereto but could be used in any optical apparatus that requires rings of detectors. One such apparatus is the multiple field-of-view lidar system.
It will be readily apparent to a person skilled in the art that a number of variations and modifications can be made without departing from the true spirit of the invention which will now be pointed out in the appended claims.
::
Transmissometers and scattering meters need to measure light at very low levels with reliability and reproducibility. Parasitic liqht, produced by scattering off optical surfaces or the dust on them, must be kept to a minimum and must not change with time in order that its effect may be subtracted accurately from the received signal. Unfortunately, the collecting optics for such apparatus are comple~ and generally involve many optical surfaces which are difficult to clean and align. This results in a large parasitic signal.
Standard optics, because of their rigid geometric disposition re~uirements, take up a lot of space which forces the overall device to be larger. This is merely annoying in an instrument designed for the laboratory.
However, for an instrument designed to perform measurements in the field, too large a size may completely preclude or at best severely curtail its use.
In order to improve the situation, apparatus has previously been designed wherein the received beam is separated into several beams by a set of beam~splitters arranged in series. At the focus of each beam an optical mask is inserted. The optical mask for the direct transmission channel has a hole of small diameter at its center. The various scattered channels have rings cut out of them. The outer and inner diameters of the rings define the acceptance angles for the scattered light. The angles ~ are related to the diameters D by the following formula:
= D
where F is the focal length of the primary lens of the receiver. The light transmitted by each mask is then :
. ,. , ........................ ~ ~
"".'1.,.','~..,~ .,, , i~ ,',~"-, ,,.j~"," ,~"~ ",,, ~, ~ .. . ,,~,",..",, ",~ " ~,",,,~
., . ' ' ;' ' ' ' :., ' ~ : ', : ' . '~
'- '. ' ' ' . : ' : ' . .
,:: , ' , , ': .' ` ' ~ . :
collected onto the detectors by short focal length lenses situated behind each mask. The lenses are disposed in such a way as to image the total entrance plane of the primary lens on the detectors.
In another prior art method, a special detector assembly is fabricated. This assembly consists of a set of ring detectors and a central circular detector. In this case, the angles of acceptance are related to the various inner and outer diameters of the detectors by the formula given above. The primary focusing lens and the face of the detector assembly are the only optical surfaces present in this method.
It has become apparent that the disadvantage of the first-mentioned prior art method is the large number of optical elements that have to be aligned precisely and then maintained in position rigidly even when the ? transmissometer-nephelometer is moved or bumped hard, as it will be in field use. The surfaces of these optical elements have to be cleaned carefully before any alignment and elaborate precautions have to be taken to snsure that they remain clean during and after the alignment. This is essential since the scattering of these surfaces will be , seen by the instrument and will considerably reduce its sensitivity and accuracy. For these reasons, maintenance of such a system is a complex undertaking.
In the second prior art method mentioned above, the limitations are principally due to electronic problems.
The optics are simple in this apparatus and involve only the primary focusing lens and the detector assembly. The first problem of an electronic nature is due to cross-talk between the various detectors. This means that some portion of the signal falling on a given detector will be seen by the others. Since the detectors of scattered light receive, in general, signals which are much smaller than the transmitted signal in the central detector of the array, they will be swamped by the induced cross-talk and :
~.
~ 208~152 their readings will be inaccurate. The second problem of an electronic nature is due to the noise inherent in the detectors. In forward-angle scattering the signal gets much weaker as the angle is increased and one would therefore like to collect it over as large an area as possible. However, if one increases the area of the detector the electronic noise increases as the square root of the area. The capacitances of the detector also increases as the area of the detector increases and this further increases the noise of the transimpedance amplifiers connected to them. The accuracy of the device is therefore severely compromised. This complication is avoided in the first prior art apparatus mentioned above but at the expense of using separate lenses to reduce the image of each ring with various magnifications onto detectors of the same size.
It is an object of the present invention to provide optical apparatus in which the above-mentioned disadvantages are reduced or substantially obviated.
According to the present invention there is provided optical apparatus including an optical fiber to receive light incident thereon at one end, and a detector located adjacent the other end of said optical fiber to receive light passing through said optical fiber and emitting from the other end thereof to be incident on said detector for analysis purposes.
According to one embodiment of the invention there is provided optical apparatus including a plurality of fibers, a plurality of detectors, said fibers being arranged in groups, and a respective detector being responsive to each group to provide an indication of the light from the respective group. The groups may comprise rings of optical fibers and each ring of optical fibers may be separated from the next by an absorbing spacer.
An embodiment of the present invention will now be described, by way of example, with reference to the 208~152 accompanying drawings in which:-Figure 1 is a diagrammatic representation ofapparatus according to the embodiment, and Figure 2 is a cross-sectional representation of a bundle of optical fibers in Figure 1.
Referring to Figure 1, scattered light is incident on an input lens 2 which coll~cts the scattered light and focuses it on the rings of optical fibers in a bundle 4.
A central circle 6 collects the light at the focus of the primary input lens 2. This is shown in Figures 1 and 2 as a central disk of fibers. Light absorbing spaces, such as 8, are provided in between the rings and these also serve as a retaining structure for the fiber rings. The numerical aperture of the fibers should be chosen to match the small f-number of the input lens, otherwise some collected light will be lost from the apparatus.
Referring to the cross-sectional view of the bundle in Figure 2, it will be seen that the groups of fibers are arranged in rings. Each ring of fibers forms a group 10, 12 or 14 which is brought out to a respective detector 16, 18 or 20. If the group size is smaller than the respective detector, then the end of the group can be simply fi~ed to the detector front face by any suitable means, as shown for detector 18. Care must also be used in order that the light emitted in the numerical aperture of the fibers does not overspill the detector active area and be lost to the apparatus. If the group size exceeds the detector size, then a short focal-length lens, aspheric in shape if need be, must be used to project the image of the fiber group onto the detector and reduce the image size to the size of the active area of the detector. Such a short focal-length lens is shown at 22 and 24.
To reduce the possibility of spurious scattering from the apparatus, the ends 26 and 28, lens 22 or 24 and adjacent respective detector 16 or 20 are held in place in - 5 _ 20841~2 a respective container 30 or 32. Each container 30 and 32 is sealed against contamination by dust and other aerosols. Assembly of these containers should be done, if possible, in a clean-room environment.
The fiber core to clad diamPter ratio should be as large as possible to ensure maximum light throughput in the fiber. The overall fiber size should be small enough so that the area of the respective scattering ring is filled uniformly. The required uniformity depends on the gradient of the scattering phase function. The phase function should not vary by more than 30% over an angular difference corresponding to the diameter of a single fiber.
For convenience in the above description, the composite assembly of fibers has been referred to as a bundle whereas each ring of fibers is identified as a group. In the art, each ring of fibers is sometimes referred to as a bundle. The composite assembly of rings may then be referred to as a cable.
It will be apparent that in the described embodiment, the use of fiber optic groups allows one to minimize the number of optical services in the received optics of transmissometers and scattering meters.
Furthermore, these optical surfaces can be cleaned once during the assembly of the apparatus and then sealed against any further contamination by dust or aerosols.
The same met~od also allows the use of physically separate detectors for each scattering or transmission channel.
This substantially prevents what is known in the art as eiectrical cross-talk from occurring. The susceptibility to parasitic scattering is reduced whilst the groups facilitate a greater flexibility in packaging the apparatus and ease considerably the optical alignment problem. The apparatus is also inherently more rugged and reliable.
Furthermore, the fiber groups permit the use of separate detectors for the transmitted channel and each of the scattering channels. Each detector can thus be optimized separately in terms of signal to noise or speed of response. The detectors are not subject to the problem of cross-talk. A signal from one channel cannot influence the other channels to a great extent.
The optical apparatus has been described as being for transmissometers and scattering meters. It will be understood that the invention is not limited thereto but could be used in any optical apparatus that requires rings of detectors. One such apparatus is the multiple field-of-view lidar system.
It will be readily apparent to a person skilled in the art that a number of variations and modifications can be made without departing from the true spirit of the invention which will now be pointed out in the appended claims.
::
Claims (9)
1. Optical apparatus including (a) an optical fiber to receive light incident thereon at one end, and (b) a detector located adjacent the other end of said optical fiber to receive light passing through said optical fiber and emitting from the other end thereof to be incident on said detector for analysis purposes.
2. Optical apparatus according to claim including (a) a plurality of fibers, (b) a plurality of detectors, (c) said fibers being arranged in groups, and (d) a respective detector being responsive to each group to provide an indication of the light from the respective group.
3. Optical apparatus according to claim 1 including a plurality of rings of optical fibers.
4. Optical apparatus according to claim 2 wherein each ring of optical fibers is separated from the next by an absorbing spacer.
5. Optical apparatus according to claim 1, 2 or 3 including a primary lens and a central circle of optical fibers to collect light at the focus of said primary lens.
6. Optical apparatus according to claim 4 including a primary lens and a central circle of optical fibers to collect light at the focus of said primary lens.
7. Optical apparatus including (a) a lens to receive scattered light, (b) an optical fiber bundle comprising a central arrangement of optical fibers and at least one ring of optical fibers therearound, (c) one end of each optical fiber being positioned to receive light passing through said lens, (d) a plurality of light detectors, and (e) each light detector being positioned so as to receive light from the other end of a different respective central arrangement or ring of said optical fibers.
8. Optical apparatus according to claim 7 wherein the end of those groups of optical fibers which is smaller than the respective detector is fixed to the detector front face by a suitable method and for those groups having a size exceeding the respective detector size, then a short focal-length lens is provided between the end of each group and its respective detector.
9. Optical apparatus according to claim 8 wherein each short focal-length lens, its associated optical fiber end and respective detector is held in a respective container which is sealed against contamination by dust.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002084152A CA2084152A1 (en) | 1992-11-30 | 1992-11-30 | Optical apparatus |
| US08/349,464 US5461476A (en) | 1992-11-30 | 1994-12-05 | Optical apparatus for receiving scattered light |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002084152A CA2084152A1 (en) | 1992-11-30 | 1992-11-30 | Optical apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2084152A1 true CA2084152A1 (en) | 1994-05-31 |
Family
ID=4150764
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002084152A Abandoned CA2084152A1 (en) | 1992-11-30 | 1992-11-30 | Optical apparatus |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US5461476A (en) |
| CA (1) | CA2084152A1 (en) |
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| US6373573B1 (en) | 2000-03-13 | 2002-04-16 | Lj Laboratories L.L.C. | Apparatus for measuring optical characteristics of a substrate and pigments applied thereto |
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| US7671988B2 (en) * | 2004-02-18 | 2010-03-02 | American Ecotech Llc | Detection of particles |
| US20050180134A1 (en) * | 2004-02-18 | 2005-08-18 | Robert Dal Sasso | Means of Achieving a Lambertian Distribution Light Source via a Light Emitting Diode Array |
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| JP6312602B2 (en) * | 2011-12-29 | 2018-04-18 | アボット・ラボラトリーズＡｂｂｏｔｔ Ｌａｂｏｒａｔｏｒｉｅｓ | Flow cytometry system and method for blocking diffraction patterns |
| CA2953026A1 (en) * | 2014-09-19 | 2016-03-24 | Hach Company | Nephelometric turbidimeter with axial illumination and circumferential photodetector |
| WO2017054070A1 (en) | 2015-10-02 | 2017-04-06 | Institut National D'optique | System and method for individual particle sizing using light scattering techniques |
| US20180217044A1 (en) * | 2017-02-02 | 2018-08-02 | Honeywell International Inc. | Forward scatter in particulate matter sensor |
| DE102018222416B4 (en) * | 2018-12-20 | 2023-01-26 | Robert Bosch Gmbh | Assembly for a LiDAR sensor and LiDAR sensor |
| WO2021099081A1 (en) * | 2019-11-22 | 2021-05-27 | Ams Ag | Optical based particulate matter sensing |
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Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3310680A (en) * | 1964-03-06 | 1967-03-21 | Hasegawa Toshitsune | Photosensitive concentration measuring apparatus for colloidal solutions |
| US3835315A (en) * | 1972-12-06 | 1974-09-10 | Us Commerce | System for determining parameters of a particle by radiant energy scattering techniques |
| US4188121A (en) * | 1977-02-01 | 1980-02-12 | Hirleman Edwin D Jr | Multiple ratio single particle counter |
| JPS59160741A (en) * | 1983-03-03 | 1984-09-11 | Toshiba Corp | Measuring device of grain size |
| JPH0658314B2 (en) * | 1985-10-28 | 1994-08-03 | 株式会社島津製作所 | Particle size distribution measuring device using laser light diffraction |
| JPS62222144A (en) * | 1986-03-25 | 1987-09-30 | Toshiba Corp | Apparatus for measuring particle size |
| JPS63215942A (en) * | 1987-03-04 | 1988-09-08 | Natl Aerospace Lab | Photoelectric conversion sensor for measuring particle size distribution |
| SE465337B (en) * | 1988-02-22 | 1991-08-26 | Btg Inc | PROCEDURE AND DEVICE FOR CONCENTRATION Saturation of Particles in a Fluid Suspended |
| JPH0676883B2 (en) * | 1988-05-18 | 1994-09-28 | 本田技研工業株式会社 | Optical sensor device |
-
1992
- 1992-11-30 CA CA002084152A patent/CA2084152A1/en not_active Abandoned
-
1994
- 1994-12-05 US US08/349,464 patent/US5461476A/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11713572B2 (en) | 2017-05-19 | 2023-08-01 | Hilti Aktiengesellschaft | Process for assembling a unitized panel for use within an exterior dynamic curtain wall assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| US5461476A (en) | 1995-10-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |