Wavelength division multiplexer and detection device

Abstract

The invention discloses a wavelength division multiplexer and a detection device, and the wavelength division multiplexer comprises a first optical filter group which comprises a first optical filter used for transmitting scattered light in an optical signal and reflecting fluorescence, and a second optical filter group which comprises a second optical filter used for transmitting the scattered light in the optical signal and reflecting the fluorescence, which are sequentially arranged along an optical path; the middle optical filter is used for reflecting scattered light in the light reflected by the first optical filter group and transmitting fluorescent light; the second optical filter group comprises second optical filters which are sequentially arranged along the light path, in the light transmission direction, the previous second optical filter transmits the fluorescent light with the first wavelength and reflects the fluorescent light with the wavelength larger than or equal to the second wavelength, and the latter second optical filter transmits the fluorescent light with the second wavelength and reflects the fluorescent light with the wavelength larger than or equal to the third wavelength; the first wavelength is smaller than the second wavelength, and the second wavelength is smaller than the third wavelength. According to the embodiment of the invention, the probability that scattered light enters a fluorescent channel is reduced, the structure is simplified, the cost is reduced, and the reliability is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a wavelength division multiplexer and a detection device. Background Art

[0002] Flow cytometers, as instruments for counting and classifying different cells, have been widely used in the medical and biological fields. The optical system of a flow cytometer is usually composed of a beam shaping module, an excitation and scattered light / fluorescence collection module, a wavelength division multiplexer module, etc.

[0003] Among them, the beam shaping module and the excitation and scattered light / fluorescence collection module are used to apply light energy to the particles to be tested, so that the particles to be tested produce scattered light and multiple fluorescences with longer wavelengths than the scattered light and collect them into the wavelength division multiplexer. The wavelength division multiplexer is used to separate the scattered light and fluorescence according to different wavelengths, and send each wavelength of light to different detectors, so as to detect the respective light energy of the scattered light and fluorescence, and finally characterize the properties of the particles.

[0004] However, the performance of wavelength division multiplexers still needs to be improved. Summary of the invention

[0005] The problem solved by the embodiments of the present invention is to provide a wavelength division multiplexer and a detection device, which reduce the probability of scattered light entering the fluorescent channel, simplify the structure, reduce the cost and improve the reliability.

[0006] To solve the above problems, an embodiment of the present invention provides a wavelength division multiplexer, which is used to separate scattered light in an optical signal and fluorescence of multiple different wavelength bands. The wavelength division multiplexer includes: the wavelength division multiplexer includes: a first filter group arranged in sequence along the optical path, including a first filter, the first filter is used to transmit the scattered light in the optical signal and reflect the fluorescence; a mid-pass filter is used to reflect the scattered light in the light reflected by the first filter group and transmit the fluorescence; a second filter group includes second filters arranged in sequence along the optical path, and along the light transmission direction, the first second filter transmits the fluorescence of the first wavelength and reflects the fluorescence of greater than or equal to the second wavelength, and the second filter transmits the fluorescence of the second wavelength and reflects the fluorescence of greater than or equal to the third wavelength, the first wavelength is smaller than the second wavelength, and the second wavelength is smaller than the third wavelength.

[0007] Optionally, the number of the first filters is one or more.

[0008] Optionally, the first filter and the plurality of second filters are arranged in two rows and in a staggered manner.

[0009] Optionally, the first optical filter and the second optical filter are arranged in a row; the wavelength division multiplexer further includes: a reflector, which is arranged opposite to and parallel to the first optical filter and the second optical filter.

[0010] Optionally, the reflectivity of the mid-pass filter to scattered light is greater than 90%.

[0011] Optionally, the transmittance of the middle filter to fluorescence is greater than 90%.

[0012] Optionally, when the light enters the middle filter, the angle between the light and the normal line of the middle filter is 0° to 70°.

[0013] Optionally, the wavelength division multiplexer further includes: a condensing lens for condensing the light transmitted by the first filter or the second filter; and a photodetector for detecting the light condensed by the condensing lens.

[0014] Optionally, the wavelength division multiplexer further includes: a collimating optical element, which is used to collimate the optical signal and inject the optical signal into the first filter group and the second filter group.

[0015] Optionally, the collimating optical element is an achromatic collimating lens.

[0016] Correspondingly, an embodiment of the present invention further provides a detection device, including: a light source providing module, used to provide an optical signal, wherein the optical signal includes scattered light and fluorescence; and a wavelength division multiplexer provided by an embodiment of the present invention.

[0017] Optionally, the light source providing module includes: a light source for emitting incident light; a beam shaping module for shaping the incident light to form a light spot at the position where the object to be measured flows, and the light spot is used to illuminate the object to be measured to generate the light signal; and a light energy collection module for collecting the light signal.

[0018] Optionally, the detection device is a flow cytometer.

[0019] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0020] The wavelength division multiplexer provided by the embodiment of the present invention further provides the mid-pass filter on the optical path between the first filter group and the second filter group. The mid-pass filter is used to reflect scattered light in the light reflected by the first filter group and transmit fluorescence, so as to further reflect the scattered light reflected by the first filter group, thereby reducing the probability of scattered light entering the subsequent fluorescence channel (i.e., the fluorescence channel formed in the second filter group) and causing crosstalk, and there is no need to additionally provide a filter in each fluorescence channel, thereby reducing the use of filters, which is beneficial to improving the performance of the wavelength division multiplexer while simplifying the structure, reducing the equipment cost and increasing the reliability of the wavelength division multiplexer.

[0021] The detection device provided by the embodiment of the present invention includes the wavelength division multiplexer provided by the embodiment of the present invention, and the scattered light and fluorescence in the optical signal are separated according to different wavelengths through the wavelength division multiplexer. The wavelength division multiplexer of the embodiment of the present invention has good separation effect and high efficiency for optical signals of different wavelengths, and has a simple structure, low cost and high reliability, which correspondingly improves the detection accuracy and reliability of the detection device, while simplifying the structure of the detection device and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of a wavelength division multiplexer in a flow cytometer;

[0023] Figure 2 It is a schematic structural diagram of an embodiment of a wavelength division multiplexer of the present invention;

[0024] Figure 3 It is a structural schematic diagram of another embodiment of the wavelength division multiplexer of the present invention;

[0025] Figure 4 It is a structural schematic diagram of another embodiment of the wavelength division multiplexer of the present invention;

[0026] Figure 5 It is a schematic structural diagram of an embodiment of a detection device of the present invention. DETAILED DESCRIPTION

[0027] As can be seen from the background technology, the performance of the current wavelength division multiplexer needs to be improved. Taking a flow cytometer as an example, the reasons why the performance of the wavelength division multiplexer needs to be improved are analyzed in combination with a wavelength division multiplexer in a flow cytometer. Figure 1 It is a schematic diagram of the structure of a wavelength division multiplexer in a flow cytometer.

[0028] Figure 1In the wavelength division multiplexer shown, a zigzag optical pattern is formed among the collimating optical element 902, the dichroic filters 903, 909, 914, 915, 916 and 917, the reference block (not shown), the concave mirrors 907, 910, 911, 912 and 913, and the focusing lenses 905, 908, 918, 919, 920 and 921; the collimating optical element 902 can capture the light from the light source 901 and project a magnified image of the object near the focusing lens 905, focusing the light to the focal position 906, and then projecting the magnified image of the object near the focusing lens 905. An angularly oriented dichroic filter 903 can be inserted into the optical path between the collimating optical element 902 and the focusing lens 905. The dichroic filter 903 allows the color band of interest to pass through and reflects the remaining colors in the light beam for further processing in the wavelength division multiplexer; between the dichroic filter 903 and the focusing lens 905, and in each optical channel formed by the concave mirror, the dichroic filter and the focusing lens, a bandpass filter 904 can be inserted after the dichroic filter to further improve the color separation capability of the wavelength division multiplexer.

[0029] Figure 1 In the flow cytometer shown, two dichroic filters are arranged between the collimating optical element 902 and the focusing lens 905, and between each concave mirror and the focusing lens, to prevent the scattered light from being reflected by the filter and entering the subsequent fluorescent channel to generate crosstalk as much as possible, or to improve the purity of the subsequent fluorescent signal. However, this is likely to increase the number of filters used, and the arrangement of two dichroic filters between the collimating optical element 902 and the focusing lens 905, and between each concave mirror and the focusing lens 905, is likely to cause an increase in cost, a complicated structure, and a decrease in reliability.

[0030] In order to solve the technical problem, an embodiment of the present invention provides a wavelength division multiplexer, in which the middle filter is further arranged on the optical path between the first filter group and the second filter group. The middle filter is used to reflect the scattered light in the light reflected by the first filter group and transmit the fluorescence, so as to further reflect the scattered light reflected by the first filter group, thereby reducing the probability of the scattered light entering the subsequent fluorescence channel (i.e., the fluorescence channel formed in the second filter group) and causing crosstalk, and there is no need to additionally arrange a filter in each fluorescence channel, thereby reducing the use of filters, which is beneficial to improving the performance of the wavelength division multiplexer while simplifying the structure, reducing the equipment cost and increasing the reliability of the wavelength division multiplexer.

[0031] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Figure 2 , showing a schematic structural diagram of an embodiment of a wavelength division multiplexer of the present invention.

[0032] In this embodiment, the wavelength division multiplexer is used to separate the scattered light and fluorescence of multiple different wavelengths in the optical signal, thereby separating the scattered light and fluorescence according to different wavelengths, and sending each wavelength of light to different detectors, so as to detect the respective light energy sizes of the scattered light and fluorescence, and finally characterize the properties of the particles to be tested.

[0033] Combined with reference Figure 2 In this embodiment, the collected optical signal includes wavelengths ranging from λ1, λ2, ... λ N of light, and λ1<λ2<……<λ N , where λ1 is the scattered light and the rest of the light is the fluorescence excited by λ1.

[0034] like Figure 2 As shown, in this embodiment, the wavelength division multiplexer includes: a first filter group 110, including a first filter 10, the first filter 10 is used to transmit scattered light in the optical signal and reflect fluorescence; a mid-pass filter 15, used to reflect scattered light in the light reflected by the first filter group 110 and transmit fluorescence; a second filter group 120, including second filters 12 arranged in sequence along the optical path, and along the light transmission direction, the first second filter 12 transmits fluorescence of the first wavelength and reflects fluorescence greater than the second wavelength, and the second second filter 12 transmits fluorescence of the second wavelength and reflects fluorescence greater than the third wavelength, the first wavelength is smaller than the second wavelength, and the second wavelength is smaller than the third wavelength.

[0035] The first filter set 110 is used to filter out the scattered light from the optical signal, so as to reduce the probability of the scattered light entering the subsequent fluorescent channel, thereby reducing the probability of crosstalk.

[0036] Specifically, in this embodiment, the first filter group 110 includes a first filter 10, which is used to transmit scattered light in the optical signal and reflect fluorescence, thereby filtering scattered light from the optical signal and reflecting the fluorescence into a subsequent optical path.

[0037] In this embodiment, the number of the first filter 10 is one or more.

[0038] As an example, the number of the first optical filter 10 is one. In other embodiments, the number of the first optical filter may be more than one.

[0039] In this embodiment, the first filter 10 is a dichroic filter.

[0040] It should be noted that, in this embodiment, the wavelength division multiplexer further includes: a collimating optical element 11 for collimating the optical signal and injecting the optical signal into the first filter group 110 and the second filter group 120 .

[0041] The optical signal is collimated by the collimating optical element 11, thereby converting the optical signal into collimated light, improving the collimation and concentration of the optical signal, thereby facilitating the transmission of subsequent optical signals in the first filter group, the mid-pass filter and the second filter group, and improving the utilization rate and detection efficiency of the optical signal.

[0042] As an example, the collimating optical element is an achromatic collimating lens, so that it can not only play a role in collimation, but also play a role in eliminating chromatic aberration.

[0043] The mid-pass filter 15 is used to reflect scattered light in the light reflected by the first filter group 110 and transmit fluorescence, so as to further reflect and filter the scattered light reflected by the first filter group 10, thereby reducing the probability of scattered light entering the subsequent fluorescence channel (i.e., the fluorescence channel formed in the second filter group 120) and causing crosstalk, and there is no need to set an additional filter in each fluorescence channel, thereby reducing the use of filters, which is beneficial to improving the performance of the wavelength division multiplexer while reducing equipment costs and increasing the reliability of the wavelength division multiplexer.

[0044] In particular, the actual filter cannot completely transmit short-wavelength scattered light, and the scattered light is much stronger than the fluorescence energy. Therefore, by also arranging the middle filter 15 in the optical path between the first filter group 110 and the second filter group 120, the filtering effect on the scattered light can be significantly improved, and the probability of the scattered light entering the second filter group 120 and causing crosstalk can be significantly reduced.

[0045] Specifically, in this embodiment, the surface of the middle filter 15 facing the first filter 10 has a film layer that reflects wavelength λ1 and transmits light of other wavelengths, so that the middle filter 15 can further filter the scattered light in the light reflected by the first filter group 110 and transmit fluorescence so that the fluorescence can be transmitted to the second filter group 120.

[0046] In this embodiment, the middle filter 15 is a dichroic filter.

[0047] The reflectivity of the middle filter 15 to the scattered light should not be too small, otherwise it will easily lead to an insignificant filtering effect of the middle filter 15 on the scattered light. Therefore, in this embodiment, the reflectivity of the middle filter 15 to the scattered light is greater than 90%.

[0048] The transmittance of the middle filter 15 to fluorescence should not be too small, otherwise it is easy to reduce the proportion and energy of the fluorescence transmitted through the middle filter 15. Therefore, in this embodiment, the transmittance of the middle filter 15 to fluorescence is greater than 90%.

[0049] It should be noted that, in a specific implementation, the mid-pass filter 15 is produced using a general economic process, which can achieve a reflectivity of about 90% to 99% for scattered light and a transmittance of about 90% or more for other wavelengths, thereby reducing the probability of scattered light entering the fluorescent channel while also reducing costs and facilitating production.

[0050] In this embodiment, in the specific implementation, compared with the solution in which the middle filter is not set in the wavelength division multiplexer, after the middle filter 15 is set in this embodiment, the scattered light entering the fluorescent channel is only 5% of the original, thereby significantly reducing the probability of scattered light entering the fluorescent channel.

[0051] It should also be noted that when the light enters the middle filter 15, the angle α between the light and the normal line of the middle filter 15 should not be too large, otherwise it is easy to reduce the proportion of scattered light reflection and the proportion of fluorescence transmission of the middle filter 15. For this reason, in this embodiment, when the light enters the middle filter 15, the angle α between the light and the normal line of the middle filter 15 is 0° to 70°.

[0052] As an example, when the light enters the middle optical filter 15 , the angle α between the light and the normal line of the middle optical filter 15 is 14°.

[0053] The second filter set 120 is used to separate the fluorescence in the optical signal according to different wavelengths.

[0054] In this embodiment, the second filter group 120 includes second filters 12 arranged in sequence along the optical path, and along the light transmission direction, the wavelength of the fluorescence transmitted by the multiple second filters 12 gradually increases, and the wavelength of the reflected fluorescence also gradually increases, and the wavelength of the fluorescence transmitted by the current second filter 12 is smaller than the wavelength of the reflected fluorescence, so that multiple fluorescences of different wavelengths can be separated by multiple second filters 12 arranged in sequence.

[0055] Specifically, in this embodiment, along the direction of light transmission, the first second filter 12 transmits fluorescence of the first wavelength and reflects fluorescence of a wavelength greater than or equal to the second wavelength, and the second filter 12 transmits fluorescence of the second wavelength and reflects fluorescence of a wavelength greater than or equal to the third wavelength, the first wavelength is smaller than the second wavelength, and the second wavelength is smaller than the third wavelength.

[0056] For example: Figure 2As shown, in the second filter group 120, the first second filter 12 along the light transmission direction transmits fluorescence with a wavelength of λ2 and reflects fluorescence with a wavelength greater than or equal to λ3; the second second filter 12 along the light transmission direction transmits fluorescence with a wavelength of λ3 and reflects fluorescence with a wavelength greater than or equal to λ4; and so on.

[0057] In this embodiment, the second filter 12 is a dichroic filter.

[0058] As an example, the first optical filter 10 and the plurality of second optical filters 12 are arranged in two rows and staggered. Specifically, the first optical filter 10 and the plurality of second optical filters 12 are arranged in two rows facing each other and staggered, so that the light reflected on the first optical filter 10 and the plurality of second optical filters 12 can be propagated in a zigzag shape between the two rows of first optical filters 10 and the plurality of second optical filters 12 facing each other and staggered, thereby increasing the compactness of the wavelength division multiplexer, which is correspondingly conducive to the miniaturization of the wavelength division multiplexer.

[0059] In this embodiment, the wavelength division multiplexer further includes: a condenser lens 13 for condensing the light transmitted by the first filter 10 or the second filter 12 ; and a photodetector 14 for detecting the light condensed by the condenser lens 13 .

[0060] The condensing lens 13 converges the light transmitted by the first filter 10 or the second filter 12 to form a focused light spot at the photodetector 14 , thereby facilitating improving the detection efficiency of the photodetector 14 .

[0061] In a specific embodiment, the condensing lens 13 corresponds to the first filter 10 or the second filter 12 one by one, so as to converge the light transmitted by each first filter 10 and the second filter 12 for detection by the photodetector.

[0062] The photoelectric detector 14 is used to detect the light focused by the focusing lens 13, so as to characterize the properties of the particles to be detected according to the detected scattered light and the fluorescence energy of different wavelengths.

[0063] In a specific implementation, the photodetector 14 may include a photomultiplier tube, a photoconductive device (photoresistor), a photovoltaic effect device, a photocell, a photovoltaic detector (such as a photodiode LED), a charge coupled device (CCD), a thermoelectric detector-thermistor, a thermopile, a pyroelectric (such as an infrared detector), etc.

[0064] Figure 3 1 is a schematic diagram of the structure of another embodiment of the wavelength division multiplexer of the present invention. The similarities between the embodiment of the present invention and the above embodiment are not repeated here. The difference between the embodiment of the present invention and the above embodiment is that:

[0065] In the first filter set (not shown), there are multiple first filters 20 .

[0066] In the present embodiment, in a scenario where there is a huge difference between the scattered light energy and the fluorescent energy, the energy of the remaining scattered light that is reflected multiple times by the multiple first filters 20 set in the first filter group is still considerable. Therefore, by adding the middle filter 25, the remaining scattered light is filtered again by the middle filter 25, and the proportion of the scattered light with a wavelength of λ1 in the fluorescent signal can be significantly reduced, thereby effectively reducing the risk of scattered light crosstalk in the fluorescent signal without adding more filters to each fluorescent channel (i.e., the channel through which light is transmitted between the multiple second filters 22 in the second filter group), thereby reducing the use of filters, reducing equipment costs and increasing system reliability.

[0067] As an example, the number of the first filters 20 in the first filter group is two. In other embodiments, based on actual needs, the number of the first filters can be greater than two.

[0068] As an example, when the light enters the middle optical filter 25 , the angle α between the light and the normal line of the middle optical filter 25 is 30°.

[0069] Figure 4 1 is a schematic diagram of the structure of another embodiment of the wavelength division multiplexer of the present invention. The similarities between the embodiment of the present invention and the above embodiment are not repeated here. The difference between the embodiment of the present invention and the above embodiment is that:

[0070] The first optical filter 30 and the second optical filter 32 are arranged in a row; the wavelength division multiplexer further includes a reflector 36 , which is arranged opposite to and parallel to the first optical filter 30 and the second optical filter 32 .

[0071] Specifically, according to the actual application scenario of the wavelength division multiplexer, the first filter 30 and the second filter 32 are arranged in a row, and the light reflected by the first filter 30 and the second filter 32 is reflected by the reflector 36 so that the light can propagate in a Z shape between the reflector 36 and the first filter 30 and the second filter 32.

[0072] In this embodiment, the number of the first optical filter 30 in the first optical filter group is one as an example for description. In other embodiments, the number of the first optical filter in the first optical filter group may also be multiple.

[0073] As an example, when the light enters the middle optical filter 35 , the angle α between the light and the normal line of the middle optical filter 35 is 64°.

[0074] Correspondingly, the present invention also provides a detection device. Figure 5 The following is a structural diagram of an embodiment of the detection device of the present invention. The detection device of this embodiment is described in detail in conjunction with the accompanying drawings.

[0075] refer to Figure 5 In this embodiment, the detection device includes: a light source providing module 200, used to provide an optical signal, wherein the optical signal includes scattered light and fluorescence; and the wavelength division multiplexer 100 described in the above embodiment.

[0076] The detection device provided in this embodiment includes the wavelength division multiplexer provided in the aforementioned embodiment, and the scattered light and fluorescence in the optical signal are separated according to different wavelengths through the wavelength division multiplexer. The wavelength division multiplexer of the aforementioned embodiment has good separation effect and high efficiency for optical signals of different wavelengths, and has a simple structure, low cost and high reliability, which correspondingly improves the detection accuracy and reliability of the detection device, while simplifying the structure of the detection device and reducing the cost.

[0077] More specifically, in this embodiment, the detection device is a flow cytometer, so that this embodiment improves the detection effect and detection reliability of the flow cytometer, simplifies the structure of the flow cytometer, and reduces the cost. In other embodiments, the detection device can also be other types of detection equipment.

[0078] The light source providing module 200 is used to provide an optical signal so that the scattered light and fluorescence in the optical signal can be separated according to different wavelengths through the wavelength division multiplexer 100 .

[0079] In this embodiment, the light source providing module includes: a light source (not shown), used to emit incident light; a beam shaping module 201, used to shape the incident light to form a light spot at the position where the object to be measured flows, and the light spot is used to illuminate the object to be measured to generate the light signal; a light energy collection module 202, used to collect the light signal.

[0080] The beam shaping module 201 performs shaping processing on the incident light, thereby changing the intensity distribution of the incident light beam, and correspondingly improving the intensity and excitation efficiency of the scattered light and fluorescence generated on the object to be measured.

[0081] As an example, the light source is a laser, and the beam shaping module 201 is correspondingly a laser shaping module.

[0082] The optical energy collection module 202 is used to collect optical signals so as to transmit the optical signals to a wavelength division multiplexer for separation of optical signals of different wavelengths for further detection.

[0083] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A wavelength division multiplexer, characterized in that: The wavelength division multiplexer is used to separate scattered light and fluorescence of multiple different wavelength bands in the optical signal, and the wavelength division multiplexer includes: A first filter group, comprising a first filter, wherein the first filter is used to transmit scattered light in the optical signal and reflect fluorescence; A middle filter, used for reflecting scattered light in the light reflected by the first filter group and transmitting fluorescence; The second filter group includes second filters arranged in sequence along the optical path, and along the light transmission direction, the first second filter transmits fluorescence of a first wavelength and reflects fluorescence of a second wavelength or greater, and the second filter transmits fluorescence of a second wavelength or greater and reflects fluorescence of a third wavelength or greater, the first wavelength is smaller than the second wavelength, and the second wavelength is smaller than the third wavelength.

2. The wavelength division multiplexer according to claim 1, characterized in that: The number of the first filters is one or more.

3. The wavelength division multiplexer according to claim 1 or 2, characterized in that: The first filter and the plurality of second filters are arranged in two rows and staggered.

4. The wavelength division multiplexer according to claim 1 or 2, characterized in that: The first optical filter and the second optical filter are arranged in a row; The wavelength division multiplexer further includes a reflector, which is arranged opposite to and in parallel with the first filter and the second filter.

5. The wavelength division multiplexer according to claim 1, characterized in that: The reflectivity of the middle filter to scattered light is greater than 90%.

6. The wavelength division multiplexer according to claim 5, characterized in that: The transmittance of the middle filter to fluorescence is greater than 90%.

7. The wavelength division multiplexer according to claim 1, characterized in that: When the light enters the middle filter, the angle between the light and the normal line of the middle filter is 0° to 70°.

8. The wavelength division multiplexer according to claim 1, characterized in that: The wavelength division multiplexer also includes: a condenser lens for converging the light transmitted by the first filter or the second filter; VDO-PA230001-CN The photoelectric detector is used to detect the light focused by the focusing lens.

9. The wavelength division multiplexer according to claim 1, characterized in that: The wavelength division multiplexer further includes a collimating optical element, which is used to collimate the optical signal and inject the optical signal into the first filter group and the second filter group.

10. The wavelength division multiplexer according to claim 9, characterized in that: The collimating optical element is an achromatic collimating lens.

11. A detection device, characterized in that: include: A light source providing module, used for providing a light signal, wherein the light signal includes scattered light and fluorescence; A wavelength division multiplexer as claimed in any one of claims 1 to 10.

12. The detection device according to claim 11, characterized in that: The light source providing module includes: a light source for emitting incident light; a beam shaping module for shaping the incident light to form a light spot at the position where the object to be measured flows, and the light spot is used to illuminate the object to be measured to generate the light signal; and a light energy collection module for collecting the light signal.

13. The detection device according to claim 11, characterized in that: The detection device is a flow cytometer.

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