OPTOELECTRONIC MEASURING DEVICE FOR MEASURING THE INTENSITY OF ELECTROMAGNETIC RADIATION IN A FREQUENCY-RESOLVED MANNER
20220283027 · 2022-09-08
Inventors
Cpc classification
G01J3/0229
PHYSICS
G01J3/0208
PHYSICS
G01J3/36
PHYSICS
G01J3/0291
PHYSICS
International classification
Abstract
An optoelectronic measuring device may be used for the frequency-resolved measurement of an intensity of electromagnetic radiation. The device may include a plurality of measurement channels. A first of the measurement channels may have a first spectral sensitivity, and a further of the measurement channels may have a further spectral sensitivity different from the first spectral sensitivity. The device may further include a plurality of collimators for collimating the electromagnetic radiation. A separate optical path may extend through each of the collimators to one or more of the measurement channels. Each of the measurement channels may be arranged to measure an intensity of the electromagnetic radiation collimated by means of one or more of the collimators. The optoelectronic measuring device may have more collimators as compared to measurement channels.
Claims
1. An optoelectronic measuring device for the frequency-resolved measurement of an intensity of electromagnetic radiation, wherein the device comprises: a plurality of measurement channels, a first measurement channel of the plurality of measurement channels having a first spectral sensitivity and a further measurement channel of the plurality of measurement channels having a further spectral sensitivity different from the first spectral sensitivity; and a plurality of collimators configured to collimate the electromagnetic radiations; wherein: a separate optical path extends through each collimator of the plurality of collimators to one or more of the measurement channels, and each of the measurement channels is arranged to measure an intensity of the electromagnetic radiation collimated by one or more collimators of the plurality of collimators; the optoelectronic measuring device comprises more collimators as compared to measurement channels.
2. The optoelectronic measuring device as claimed in claim 1, wherein each collimator of the plurality of collimators has precisely one collimation lens and precisely one aperture diaphragm.
3. The optoelectronic measuring device as claimed in claim 2, wherein a diaphragm membrane of the aperture diaphragm is monolithically connected to the collimation lens.
4. The optoelectronic measuring device as claimed in claim 1, wherein each collimator of the plurality of collimators includes a collimation lens and an aperture diaphragm, the aperture diaphragms having a common diaphragm membrane.
5. The optoelectronic measuring device as claimed in claim 1, wherein each collimator of the plurality of collimators comprise a collimation lens and an aperture diaphragm, the collimation lenses being monolithically connected.
6. The optoelectronic measuring device as claimed in claim 5, wherein the aperture diaphragms have a common diaphragm membrane, which comprises a layer on the monolithically connected collimation lenses.
7. The optoelectronic measuring device as claimed in claim 1, further comprising at least one radiation absorption element arranged between two collimators of the plurality of collimators.
8. The optoelectronic measuring device as claimed in claim 1, wherein each measurement channel of the plurality of measurement channels have precisely one continuously configured radiation detection element and one spectral filter.
9. The optoelectronic measuring device as claimed in claim 8, wherein each radiation detection element is a continuously configured photodiode.
10. The optoelectronic measuring device as claimed in claim 1, wherein each measurement channel of the plurality of the measurement channels are respectively assigned precisely n collimators, where n is a natural number greater than or equal to two, in such a way that these measurement channels are arranged to register the electromagnetic radiation collimated by the respectively assigned collimators.
11. The optoelectronic measuring device as claimed in claim 1, wherein the plurality of measurement channels comprises at least 5 measurement channels, wherein the plurality of collimators comprises at least 5 collimators, or combinations thereof.
12. The optoelectronic measuring device as claimed in claim 1, further comprising a radiation distribution means configured to distribute the electromagnetic radiation among the plurality of collimators.
13. A method for the frequency-resolved measurement of an intensity of electromagnetic radiation, wherein the method comprises: Collimating the electromagnetic radiation by means of a plurality of collimators; and measuring the intensity of the electromagnetic radiation by means of a plurality of measurement channels, a first measurement channel of the plurality of measurement channels having a first spectral sensitivity and a further measurement channel of the plurality of measurement channels having a further spectral sensitivity different from the first spectral sensitivity; wherein: a separate optical path extends through each collimator of the plurality of collimators to one or more measurement channels of the plurality of measurement channels, and each measurement channel of the plurality of measurement channels measures the intensity of the electromagnetic radiation collimated by means of one or more collimators of the plurality of collimators; wherein more collimators are used for collimating the electromagnetic radiation than measurement channels are used for measuring the intensity.
14. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Various embodiments of the solution will be explained in more detail below with the aid of the drawings, in which schematically:
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[0040] Identical, similar or similar-acting elements are given the same reference signs in the Figures. The Figures and the proportions of the elements shown in the Figures are not to be regarded as true to scale. Rather, individual elements can be shown exaggeratedly large for better representability and/or for better comprehensibility.
DETAILED DESCRIPTION
[0041] An optoelectronic measuring device 1 according to a first example is schematically represented in
[0042] A housing section 2a, which serves as a holder for the diaphragm membranes B.sub.1, B.sub.2 and the collimation lenses L.sub.1, L.sub.2, is respectively arranged between the diaphragm membranes B.sub.1, B.sub.2 and between the collimation lenses L.sub.1, L.sub.2.
[0043] The first measurement channel M.sub.1 comprises a first spectral filter F.sub.1 and a first radiation detection element D.sub.1. In a similar way, the second measurement channel M.sub.2 comprises a second spectral filter F.sub.2 and a second radiation detection element D.sub.2.
[0044] Detectors have a sensitive spectral range. This is the wavelength range in which electromagnetic radiation is detected. A detector may have a wavelength-dependent sensitivity, also referred to as spectral sensitivity, so that different wavelengths with the same intensity generate differently strong detector signals, for example voltages or currents.
[0045] The two spectral filters F.sub.1 and F.sub.2 have different filter characteristics, so that the measurement channels M.sub.1 and M.sub.2 have different spectral sensitivities. Accordingly, the intensity of the electromagnetic radiation 10 may be measured in frequency-resolved fashion with the optoelectronic measuring device 1.
[0046] By the collimation of the electromagnetic radiation 10, it is possible to ensure that the measurement channels M.sub.1 and M.sub.2 have spectral sensitivities substantially independent of an angle of incidence of the electromagnetic radiation 10, even if the filter characteristics of the spectral filters F.sub.1, F.sub.2 have a strong angle dependency.
[0047] The spectral filters F.sub.1, F.sub.2 may, in particular, be bandpass filters. The filter characteristics of bandpass filters may have a strong angle dependency, particularly when multilayer interference filters are used as bandpass filters.
[0048] The radiation detection elements D.sub.1 and D.sub.2 are a component of a detector array 4. A scattering element 3 for scattering the electromagnetic radiation 10 is arranged before the collimators K.sub.1, K.sub.2. The radiation detection elements D.sub.1, D.sub.2 may be identically designed silicon photodiodes.
[0049] The optoelectronic measuring device 1 has a plurality of collimators K.sub.1 and K.sub.2. It has precisely one collimator K.sub.1, K.sub.2 per measurement channel M.sub.1, M.sub.2. The collimators K.sub.1 and K.sub.2 are not “optically connected in series”, i.e. the electromagnetic radiation 10 does not pass first through one of the collimators K.sub.1, K.sub.2 and then through the other of the collimators K.sub.2, K.sub.2. Rather, the collimators K.sub.1, K.sub.2 are “optically connected in parallel”. This does not mean that the collimators K.sub.1, K.sub.2 must be aligned parallel, but that a separate optical path extends through each of the collimators K.sub.1, K.sub.2 to one or more of the measurement channels M.sub.1, M.sub.2. Accordingly, both the electromagnetic radiation 10 allowed through by the first collimator K.sub.1 and the electromagnetic radiation 10 allowed through by the second collimator K.sub.2 are available for the measurement.
[0050] In comparison with an optoelectronic measuring device having one collimator, collimators K.sub.1, K.sub.2 with a smaller height may therefore be used. The height of the optoelectronic measuring device 1 is given by the sum of the focal length f of the collimation lenses L.sub.1, L.sub.2, the thickness t of the lenses and the working distance a, which is equal to the separation between the collimation lenses L.sub.1, L.sub.2 and the spectral filters F.sub.1, F.sub.2 and may be equal to zero. Accordingly, the height of the optoelectronic measuring device 1 is limited by the focal length f of the lenses and the thickness t of the lenses L.sub.1, L.sub.2.
[0051] When using only one collimator, in order to register the same intensity of electromagnetic radiation with the optoelectronic measuring device as in the first example here, the aperture diaphragm would have to be selected to be greater than in the present example. In order to obtain the same beam divergence after the collimators as in the present example in such a case, it would be necessary to increase the focal length of the lens and also make the lens larger, so that it also becomes thicker. Accordingly, the height (focal length f and thickness t) of the optoelectronic measuring device 1 is reduced through the use of a plurality of collimators K.sub.1, K.sub.2 in comparison with the use of only one collimator according to the prior art. Likewise, a sensitivity of the optoelectronic measuring device 1 may be increased through the use of a plurality of collimators K.sub.1, K.sub.2, by more electromagnetic radiation 10 being brought to the measurement channels M.sub.1, M.sub.2.
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[0053] Instead of two collimators K.sub.1, K.sub.2, it furthermore has k collimators K.sub.1, K.sub.2, . . . , K.sub.k, where k is equal to m, i.e. the optoelectronic device has precisely as many collimators as measurement channels. Here, nine collimators K.sub.1, K.sub.2, . . . , K.sub.k are represented.
[0054] All the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m have different spectral sensitivities. In other words, the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m respectively have a spectral sensitivity which differs from the spectral sensitivity of all other measurement channels M.sub.1, M.sub.2, . . . , M.sub.m.
[0055] Consequently, with the optoelectronic measuring device 1 according to the second example, with the use of more than 2 measurement channels, a frequency-resolved measurement of the intensity of the electromagnetic radiation 10 may be carried out with a more accurate spectral resolution than with the optoelectronic measuring device 1 according to the first example. When using more than 2 collimators K.sub.1, K.sub.2, . . . , K.sub.k, this may be done without increasing the height (in particular focal length f and thickness t) of the optoelectronic measuring device 1.
[0056] As mentioned, as an alternative to the nine measurement channels and collimators represented, the optoelectronic measuring device 1 may also have a number m of measurement channels M different thereto and a number k of collimators K different thereto. For example, it may have at least 5 or at least 10 or at least 50 measurement channels M and collimators K.
[0057] In contrast to the first example, in which there are two diaphragm membranes B.sub.1, B.sub.2 between which a housing section 2a that serves as a holder for the diaphragm membranes B.sub.1, B.sub.2 is arranged, the collimators K.sub.1, K.sub.2, . . . , K.sub.9 have a common diaphragm membrane B and the housing section 2a in between is omitted.
[0058] The collimation lenses L.sub.1, L.sub.2, . . . , L.sub.k are formed monolithically, i.e. formed consisting of one piece. For example, they may be produced together in an injection molding method. A lens array formed from such monolithic collimation lenses L.sub.1, L.sub.2, . . . , , L.sub.k may be positioned and handled easily.
[0059] In contrast to the optoelectronic measuring device 1 according to the first example, no housing section 2a is accordingly arranged between the collimation lenses L.sub.1, L.sub.2.
[0060] As represented in
[0061] In order to prevent such a crosstalk between the collimators K.sub.1, K.sub.2, . . . , K.sub.k, at least one radiation absorption element 5 may additionally be arranged between the collimators K.sub.1, K.sub.2, . . . , K.sub.k. The optoelectronic measuring device 1 according to a third example, which is represented in
[0062] The optoelectronic measuring device 1 according to a fourth example, which is represented in
[0063] In contrast to the optoelectronic measuring device 1 according to the third example, the optoelectronic measuring device 1 according to the fourth example, which is represented in
[0064] The optoelectronic measuring devices 1 according to examples one to four, which have been discussed above, comprise precisely one assigned collimator K.sub.1, K.sub.2, . . . , K.sub.k per measurement channel M.sub.1, M.sub.2, . . . , M.sub.m. In this case, the measurement channel M.sub.1, M.sub.2, . . . M.sub.m is arranged to register predominantly the electromagnetic radiation 10 collimated by means of the respectively assigned collimator K.sub.1, K.sub.2, . . . , K.sub.k, i.e. at least 50% of the electromagnetic radiation 10 registered by the respective measurement channel M.sub.1, M.sub.2, . . . , M.sub.m comes from the assigned collimator K.sub.1, K.sub.2, . . . , K.sub.k. Accordingly, the optoelectronic measuring device 1 according to the exemplary embodiments one to four comprises precisely as many measurement channels M.sub.1, M.sub.2, . . . , M.sub.m as collimators K.sub.2, K.sub.2, . . . , K.sub.k.
[0065] The optoelectronic measuring device 1 according to a first exemplary embodiment, which is represented in
[0066] The optoelectronic measuring device 1 according to a second exemplary embodiment, which is represented in
[0067] As an alternative thereto, the at least two measurement channels M.sub.1, M.sub.2, . . . , M.sub.m may respectively be assigned precisely n collimators K.sub.1, K.sub.2, . . . , K.sub.k, where n is a natural number greater than two.
[0068] By the use of a plurality of collimators K.sub.1, K.sub.2, . . . , K.sub.k per measurement channel M.sub.1, M.sub.2, . . . , M.sub.m according to the first and second exemplary embodiments, the height of the collimators K.sub.1, K.sub.2, . . . , K.sub.k (focal length f and lens thickness t) may be further reduced. Furthermore, the sensitivity of the optoelectronic measuring device 1 may thereby be increased since more electromagnetic radiation 10 can be guided to the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m. Owing to the assignment of a fixed number of collimators K.sub.1, K.sub.2, . . . , K.sub.k to each measurement channel M.sub.1, M.sub.2, . . . , M.sub.m according to the second exemplary embodiment, the collimators K.sub.1, K.sub.2, . . . , K.sub.k may be aligned identically relative to the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m for all the measurement channels M.sub.1, M.sub.2, M.sub.m, in order straightforwardly to ensure that the same intensity of electromagnetic radiation 10 is present at all the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m.
[0069] The optoelectronic measuring device 1 according to a fifth example, which is represented in
[0070] The optoelectronic measuring device 1 according to a sixth example, which is represented in
[0071] As an alternative thereto, the at least two collimators K.sub.1, K.sub.2, . . . , K.sub.k may respectively be assigned precisely n measurement channels M.sub.1, M.sub.2, . . . , M.sub.m, where n is a natural number greater than two.
[0072] By the use of a plurality of measurement channels M.sub.1, M.sub.2, . . . , M.sub.m per collimator K.sub.1, K.sub.2, . . . , K.sub.k according to the fifth and sixth examples, in comparison with the optoelectronic measuring device 1 according to the second example, it is possible to save on collimators K.sub.1, K.sub.2, . . . , K.sub.k and thereby reduce production costs. By the assignment of a fixed number of measurement channels M.sub.11, M.sub.2, . . . , M.sub.m to each collimator K.sub.1, K.sub.2, . . . , K.sub.k according to the sixth example, the collimators K.sub.1, K.sub.2, . . . , K.sub.k may be aligned relative to the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m in such a way that there is the same intensity of electromagnetic radiation 10 at all the measurement channels M.sub.1, M.sub.2, . . . , M.sub.m.
[0073] The above-described optoelectronic measuring devices 1 according to the first and second exemplary embodiments and fifth and sixth examples may, in particular, also be modified in such a way that, as described in connection with the third example, absorption elements 5 are arranged between the collimators K.sub.1, K.sub.2, . . . , K.sub.k. Furthermore, the diaphragm membrane B of the collimators K.sub.1, K.sub.2, . . . , K.sub.k may, as described in connection with the fourth example, comprise or consist of a layer on the collimation lenses L.sub.1, L.sub.2, . . . , L.sub.k.
[0074] The above-described optoelectronic measuring devices 1 according to the first and second exemplary embodiments and fifth and sixth examples may, in a similar way to the second to fourth examples, have at least 5 or at least 10 or at least 50 measurement channels M. Likewise, they may have at least 5 or at least 10 or at least 50 collimators K.
[0075] The above-described optoelectronic measuring devices 1 according to the second to sixth examples and the first and second exemplary embodiments may, in particular, also be modified in such a way that, as described in connection with the first example, the collimation lenses L.sub.1, L.sub.2, . . . , L.sub.k are not monolithically connected to one another. Furthermore, they may also be modified in such a way that the collimators K.sub.1, K.sub.2, . . . , K.sub.k do not have a common diaphragm membrane B, but rather each collimator K.sub.1, K.sub.2, . . . , K.sub.k has its own diaphragm membrane B.
[0076] In all exemplary embodiments and examples, the collimation lenses L.sub.1, L.sub.2, . . . , L.sub.k used in the respective exemplary embodiment or example may have different optical properties. In a non-limiting embodiment, they have identical optical properties. Likewise, the collimators K.sub.1, K.sub.2, . . . , K.sub.k of a respective exemplary embodiment or example may have identical optical properties. The collimation lenses L.sub.1, L.sub.2, . . . , L.sub.k may, in all exemplary embodiments and examples, comprise glass and/or plastic or consist of glass or consist of plastic. In all exemplary embodiments and examples, the collimation lenses L.sub.1, L.sub.2, . . . , L.sub.k are transparent for the electromagnetic radiation 10 to be measured.
[0077]
[0078] It comprises:
[0079] S0: “Start”,
[0080] S1: “Collimation of the electromagnetic radiation (10) by means of at least two collimators (K.sub.1, K.sub.2, . . . , K.sub.k)”,
[0081] S2: “Measurement of the intensity of the electromagnetic radiation (10) by means of at least two measurement channels”,
[0082] SE: “End”.
[0083] Step S2 is carried out after Step S1. In Step S2, a first of the measurement channels (M.sub.1) has a first spectral sensitivity and a further of the measurement channels (M.sub.2, . . . , M.sub.m) has a further spectral sensitivity, which differs from the first spectral sensitivity.
[0084] Steps S1 and S2 are carried out in such a way that a separate optical path extends through each of the collimators (K.sub.2, K.sub.2, . . . , K.sub.k) to one or more of the measurement channels (M.sub.1, M.sub.2, . . . , M.sub.m), and each of the measurement channels (M.sub.2, M.sub.2, . . . , M.sub.m) measures the intensity of the electromagnetic radiation (10) collimated by means of one or more of the collimators (K.sub.1, K.sub.2, . . . , K.sub.k).
[0085] In the method, more collimators (K.sub.2, K.sub.2, . . . , K.sub.k) will be used for collimating the electromagnetic radiation (10) than measurement channels (M.sub.2, M.sub.2, . . . , M.sub.m) will be used for measuring the intensity.
[0086] In the method, an optoelectronic measuring device (1) according to one of the exemplary embodiments described above may be used.
LIST OF REFERENCES
[0087] 1 optoelectronic measuring device [0088] 2 housing [0089] 2a housing section [0090] 3 scattering element [0091] 4 detector array [0092] 5 radiation absorption elements [0093] 10 electromagnetic radiation [0094] K.sub.1, K.sub.2, . . . , K.sub.k collimator 1, collimator 2, . . . , collimator k [0095] A.sub.1, A.sub.2, . . . , A.sub.k aperture diaphragm 1, aperture diaphragm 2, . . . , aperture diaphragm k [0096] B.sub.1, B.sub.2 diaphragm membrane 1, diaphragm membrane 2 [0097] B common diaphragm membrane [0098] L.sub.1, L.sub.2, . . . , L.sub.k collimation lens 1, collimation lens 2, collimation lens k [0099] M.sub.1, M.sub.2, . . . , M.sub.m measurement channel 1, measurement channel 2, . . . , measurement channel m [0100] D.sub.1, D.sub.2, . . . , D.sub.m radiation detection element 1, radiation detection element 2, radiation detection element m [0101] F.sub.1, F.sub.2, . . . , F.sub.m spectral filter 1, spectral filter 2, . . . , spectral filter m [0102] f focal length [0103] t thickness [0104] a working distance