Optical sensor and photosynthetic organism growth monitoring method

Abstract

The invention provides an optical sensor which is used for monitoring growth information of photosynthetic organisms. The optical sensor comprises a main body which is provided with a transmitting window and a receiving window which are oppositely arranged at an interval; the light source is positioned in the main body and is used for emitting first reference light and second reference light with different wavelengths through the emission window; the receiver is positioned in the main body and is used for receiving first detection light generated after the first reference light passes through the photosynthetic organism through the receiving window and receiving second detection light generated after the second reference light passes through the photosynthetic organism through the receiving window; an electric signal is generated according to the first detection light and the second detection light; and the control circuit is electrically connected with the light source and the receiver and is used for receiving the electric signal and acquiring the growth information of the photosynthetic organisms based on the electric signal. The invention further provides a photosynthetic organism growth monitoring method.

Description

Technical Field

[0001] The present application relates to the technical field of photosynthetic organism monitoring and cultivation, and in particular to an optical sensor and a photosynthetic organism growth monitoring method applied to the optical sensor. Background Art

[0002] The pigment content and composition in the cells of photosynthetic organisms vary greatly at different growth stages, and it is difficult to calculate the dry weight by measuring the absorbance using ordinary optical sensors. Summary of the invention

[0003] In a first aspect, the present application provides an optical sensor for monitoring growth information of photosynthetic organisms; the optical sensor comprises: a main body, formed with an emitting window and a receiving window that are relatively and spaced apart; a light source, located in the main body, for emitting a first reference light and a second reference light with different wavelengths through the emitting window; a receiver, located in the main body, for receiving a first detection light generated after the first reference light passes through the photosynthetic organism through the receiving window, and for receiving a second detection light generated after the second reference light passes through the photosynthetic organism through the receiving window, and generating an electrical signal according to the first detection light and the second detection light; and a control circuit, electrically connecting the light source and the receiver, for receiving the electrical signal, and acquiring the growth information of the photosynthetic organism based on the electrical signal.

[0004] A second aspect of the present application provides a photosynthetic organism growth monitoring method, which is applied to the above-mentioned optical sensor; the photosynthetic organism growth monitoring method includes: controlling a light source to emit a first reference light and a second reference light; controlling a receiver to receive a first detection light and a second detection light through the receiving window, and receiving an electrical signal from the receiver, wherein the electrical signal is generated based on the first detection light and the second detection light; and obtaining growth information of the photosynthetic organism based on the electrical signal based on a preset absorption spectrum curve.

[0005] The above optical sensor and photosynthetic organism growth monitoring method emit a first reference light and a second reference light of different wavelengths through a light source to detect the growth information of photosynthetic organisms based on the reference lights of different wavelengths. Since reference lights of different wavelengths have different optical properties, the different growth information of photosynthetic organisms (such as microalgae, duckweed, etc.) detected by the reference lights of different wavelengths are integrated to make the detection data more accurate. The optical sensor can be used in a photosynthetic organism culture system to continuously monitor the growth of photosynthetic organisms for a long time, which is of great significance for a photosynthetic organism culture system with constant turbidity and continuous culture. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 FIG. 4 is a three-dimensional structural diagram of an optical sensor according to an embodiment of the present application.

[0007] Figure 2 Another three-dimensional structural diagram of the optical sensor according to an embodiment of the present application.

[0008] Figure 3 This is an exploded structural diagram of an optical sensor according to an embodiment of the present application.

[0009] Figure 4 It is a three-dimensional structural diagram of the optical sensor of the embodiment of the present application in the detection state.

[0010] Figure 5 This is a flow chart of the steps of the photosynthetic organism growth monitoring method according to an embodiment of the present application.

[0011] Main component symbols Optical sensor: 1; Body: 10; First installation part: 11; First surface: 111; Launch window: 112; Second mounting part: 12; Second surface: 121; Receive window: 122; Connecting columns: 13; Containment space: 14; Light source: 20; Receiver: 30; Rotor assembly: 40; Active rotor: 41; Shade: 411; Light-transmitting part: 412; Passive rotor: 42; Bearings: 43; Motor: 50; Signal line: 60; Axis of rotation: L.

[0012] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0013] The present application provides an optical sensor, which is applied to a photosynthetic organism culture system to monitor the growth status of photosynthetic organisms (such as microalgae, duckweed, etc.) in real time, and continuously transmit back photosynthetic organism growth information (including cell dry weight, pigment content, cell wall component content, cell membrane and other component content of photosynthetic organisms, etc.). In this embodiment, the structure and function of the optical sensor are illustrated by taking the optical sensor used to detect the growth information of microalgae cells as an example.

[0014] See also Figure 1The optical sensor 1 of the embodiment of the present application includes a main body 10, a light source 20 and a receiver 30 located in the main body 10. The light source 20 is used to emit reference light, and the reference light passes through the culture algae liquid and is received by the receiver 30 as detection light. The receiver 30 is used to generate an electrical signal based on the detection light. The electrical signal can be used to obtain the growth information of the microalgae cells in the culture matrix.

[0015] In this embodiment, the main body 10 has a first mounting portion 11, a second mounting portion 12 and four connecting columns 13. The first mounting portion 11 and the second mounting portion 12 are both generally hollow rectangular parallelepiped structures. The connecting columns 13 are spaced and parallel to each other. Each connecting column 13 extends from a vertex of the first mounting portion 11 to a vertex of the second mounting portion 12. In this embodiment, the first mounting portion 11, the second mounting portion 12 and the connecting columns 13 are integrally formed.

[0016] Please also read Figure 1 and Figure 2 The first mounting portion 11 has a first surface 111 facing the second mounting portion 12, and an emission window 112 is formed on the first surface 111. The light source 20 is located in the first mounting portion 11 and at the emission window 112, and is used to emit reference light through the emission window 112.

[0017] The second mounting portion 12 has a second surface 121 facing the first mounting portion 11, and a receiving window 122 is formed on the second surface 121. The first surface 111 and the second surface 121 are spaced apart and parallel to each other. The receiver 30 is located in the second mounting portion 12 and at the receiving window 122, and is used to receive the detection light incident from the receiving window 122.

[0018] The area of ​​the main body 10 where the transmitting window 112 and the receiving window 122 are formed is made of a light-transmitting material, and the remaining area is made of a light-shielding material. Since the optical sensor 1 is always immersed in the cultured algae liquid during use, the main body 10 is made of PC plastic, which can resist corrosion, dirt and other forms of damage caused by exposure to salt water or other substances in the water.

[0019] In this embodiment, the transmitting window 112 and the receiving window 122 are circular windows respectively. The transmitting window 112 and the receiving window 122 have the same area, or the receiving window 122 has an area slightly larger than that of the transmitting window 112, so as to more effectively receive the detection light. The positive projection of the receiving window 122 on the first surface 111 completely covers the transmitting window 112, which is conducive to more effectively receiving the detection light on the one hand, and on the other hand, the reference light emitted from the transmitting window 112 can be used as the detection light to enter the receiving window 122 horizontally, which is conducive to minimizing the light attenuation and distortion caused by reflection, refraction, and scattering during the light propagation process.

[0020] In this embodiment, the four connecting pillars 13 form a receiving space 14 between the first mounting portion 11 and the second mounting portion 12. When the optical sensor 1 is immersed in the microalgae culture solution, the cultured algae solution can enter the receiving space 14 from the area between the connecting pillars 13. At this time, the reference light is emitted from the emission window 112 and passes through the cultured algae solution, so that the optical properties of the reference light are changed, and enters the receiving window 122 as the detection light.

[0021] The light source 20 is used to simultaneously or time-sharingly emit a first reference light and a second reference light of different wavelengths. In this embodiment, the first reference light is an infrared light of a wavelength of 940 nm, and the second reference light is a light of a wavelength of 450 nm. The optical sensor 1 uses the light source 20 of the above-mentioned specific wavelength and utilizes the absorption characteristics of microalgae cells to light of different wavelengths to accurately measure the concentration of microalgae cells.

[0022] The first reference light with a wavelength of 940nm (infrared light) has the following characteristics: 1. Water absorption characteristics: Light with a wavelength of 940nm is less absorbed in water, so it can penetrate the water layer without losing too much energy. This is especially important for measuring the concentration of microalgae in water because it reduces the interference of water on the light signal.

[0023] 2. Cell structure penetration: Infrared light can penetrate cell walls and cell membranes to reach the interior of the cell. This makes it possible to measure the properties of the entire cell, not just the cell surface.

[0024] 3. Chlorophyll absorbs less: Compared with other wavelengths of light, chlorophyll absorbs less light at 940nm wavelength, thus reducing the interference of chlorophyll on the measurement signal and making the measurement results more accurate.

[0025] The second reference light with a wavelength of 450nm has the following characteristics: 1. Chlorophyll absorption peak: Light with a wavelength of 450nm is located in a peak area of ​​the chlorophyll absorption spectrum. Chlorophyll is an important pigment for photosynthesis of microalgae. It strongly absorbs light in the blue light region, especially light around 450nm.

[0026] 2. Measuring photosynthetic activity: By measuring the absorption of 450nm light by microalgae, its photosynthetic activity and biomass can be indirectly assessed. This is because the amount of light absorbed by chlorophyll (chlorophyll content) is directly related to the growth state of the cell (under appropriate light intensity, cells in good growth condition usually have higher chlorophyll content. Under appropriate lighting conditions, the growth rate of cells usually increases, which means that cells need more energy and reducing power (such as ATP and NADPH) to support the biosynthesis process. Therefore, cells will increase the chlorophyll content to enhance photosynthesis to meet these needs. As cells age, the chlorophyll content usually decreases because the degradation rate of chlorophyll molecules exceeds the synthesis rate. The reduction in chlorophyll content will lead to reduced photosynthesis efficiency, weakened cell growth and metabolic activity, and may eventually lead to cell death).

[0027] Thus, in this embodiment, the first reference light of 940nm and the second reference light of 450nm are selected so that the optical sensor 1 can combine the measurement data of the two, and more accurately calculate the concentration of microalgae and evaluate its growth status by comparing and analyzing the light absorption at different wavelengths, which is beneficial to improve the measurement accuracy, reduce errors, and provide important information about the growth status of microalgae.

[0028] In this embodiment, the light source 20 includes two light emitting diodes that can emit the first reference light and the second reference light respectively. In other embodiments of the present application, the wavelength of the second reference light can be changed according to different information to be detected.

[0029] The receiver 30 is used to receive the first detection light generated by the first reference light passing through the cultured algae liquid through the receiving window 122, and is used to receive the second detection light generated by the second reference light passing through the cultured algae liquid through the receiving window 122. In this embodiment, the receiver 30 includes a photodiode, which is used to convert the first detection light and the second detection light into electrical signals for output through photoelectric conversion.

[0030] In this embodiment, the optical sensor 1 further includes a rotor assembly 40 movably connected between the first mounting portion 11 and the second mounting portion 12 . That is, the rotor assembly 40 is movably connected between the first surface 111 and the second surface 121 , and is located in the receiving space 14 .

[0031] See also Figure 3The rotor assembly 40 includes an active rotor 41, a passive rotor 42 and a bearing 43. The active rotor 41 and the passive rotor 42 are separate structures and are arranged around the bearing 43. The optical sensor 1 also includes a motor 50. The motor 50 is fixedly arranged on a side of the first mounting portion 11 away from the first surface 111, and is connected to the active rotor 41, and is used to drive the active rotor 41 to rotate around the rotation axis L (that is, around the axis of the bearing 43). The motor 50 can drive the active rotor 41 to rotate forward (clockwise around the rotation axis L) and reverse (counterclockwise around the rotation axis L). The rotation axis L is perpendicular to the first surface 111 and the second surface 121, respectively.

[0032] The passive rotor 42 is not connected to the motor 50. When the passive rotor 42 is located in the rotation direction of the active rotor 41, the active rotor 41 contacts the passive rotor 42 and pushes the passive rotor 42 to rotate synchronously.

[0033] In this embodiment, the active rotor 41 and the passive rotor 42 are both solid columnar structures. The two ends of the active rotor 41 and the passive rotor 42 are in contact with the first surface 111 and the second surface 121 respectively. In the process of rotating around the rotation axis L, the two ends of the active rotor 41 and the passive rotor 42 always keep in contact with the first surface 111 and the second surface 121 respectively.

[0034] In this embodiment, the ends of the active rotor 41 and the passive rotor 42 that contact the first surface 111 jointly cover a portion of the first surface 111, so that the emission window 112 can be exposed relative to the rotor assembly 40, and the active rotor 41 and / or the passive rotor 42 are prevented from covering the emission window 112 and affecting the emission of the reference light. Similarly, the ends of the active rotor 41 and the passive rotor 42 that contact the second surface 121 jointly cover a portion of the second surface 121, so that the receiving window 122 can be exposed relative to the rotor assembly 40, and the active rotor 41 and / or the passive rotor 42 are prevented from covering the receiving window 122 and affecting the reception of the detection light.

[0035] The active rotor 41 includes a light shielding portion 411 and a light transmitting portion 412. The light transmitting portion 412 is embedded in the light shielding portion 411. The two ends of the light shielding portion 411 contact the first surface 111 and the second surface 121 respectively. The light shielding portion 411 is provided with a through hole penetrating the two ends. The light transmitting portion 412 is filled in the through hole and is exposed relative to the two ends of the light shielding portion 411. The two ends of the light transmitting portion 412 also contact the first surface 111 and the second surface 121 respectively. The end of the light transmitting portion 412 contacting the first surface 111 has the same shape and area as the transmitting window 112, and the end of the light transmitting portion 412 contacting the second surface 121 has the same shape and area as the receiving window 122.

[0036] In this embodiment, the light shielding portion 411 and the passive rotor 42 are made of PC plastic, which can resist corrosion, dirt and other forms of damage caused by exposure to salt water or other substances in water, and the light-transmitting portion 412 is a cylindrical glass component.

[0037] In this embodiment, in addition to realizing the function of monitoring the growth state of microalgae, the optical sensor 1 also realizes the light shielding, self-calibration and self-cleaning functions of the optical sensor 1 through the rotor assembly 40. In the process of realizing the above functions, the active rotor 41 and the passive rotor 42 may need to rotate to shield part or all of the transmitting window 112 and the receiving window 122. In order to ensure that the active rotor 41 and the passive rotor 42 can shield part or all of the transmitting window 112 and the receiving window 122, in this embodiment, the transmitting window 112 and the receiving window 122 are located within the rotation path range of the active rotor 41 and the passive rotor 42. In this embodiment, the rotation path range of the active rotor 41 and the passive rotor 42 is defined as the range passed by the first surface 111 and the second surface 121 during the 360-degree rotation of the active rotor 41 and the passive rotor 42 around the rotation axis L.

[0038] In this embodiment, the optical sensor 1 further includes a signal line 60 fixedly connected to the main body 10 and a control circuit (not shown) located in the main body 10. The control circuit is electrically connected to the light source 20, the receiver 30, the motor 50 and the signal line 60 respectively (for example, by setting a wire in the main body 10 to realize the electrical connection between the components), and is used to control the light source 20 to emit the first reference light and the second reference light, control the motor 50 to drive the active rotor 41 to rotate, receive the electrical signal from the receiver 30, and generate microalgae growth information according to the electrical signal. The signal line 60 is also connected to the device outside the optical sensor 1, and is used to transmit the growth information obtained by the control circuit to the external device for display, recording or further analysis.

[0039] The working mode of the optical sensor 1 is described as follows. It should be noted that the optical sensor 1 is kept immersed in the microalgae culture solution during operation.

[0040] 1. Self-calibration: Since there may be differences in the readings of different optical sensors 1 , the present application calibrates the optical sensor 1 before the optical sensor 1 is put into formal use.

[0041] The control circuit controls the motor 50 to work, and drives the active rotor 41 to rotate through the motor 50 until the light-transmitting portion 412 in the active rotor 41 rotates to the optical window and completely covers the optical window (that is, the end of the light-transmitting portion 412 contacting the first surface 111 completely covers the transmitting window 112, and the end of the light-transmitting portion 412 contacting the second surface 121 completely covers the receiving window 122). Since the light-transmitting portion 412 has a high light transmittance, its transmittance is 1%-100%. At this time, the reference light emitted from the transmitting window 112 can be directly transmitted along the light-transmitting portion 412 to the receiving window 122. At this time, the intensity of the detection light received by the receiver 30 is the largest, and the amplitude of the electrical signal generated at this time is recorded.

[0042] When the shading portion 411 completely covers the optical window, the reference light emitted from the transmitting window 112 is completely blocked by the shading portion 411, and the receiver 30 can hardly receive the detection light. That is, the intensity of the detection light received by the receiver 30 is the smallest at this time, and the amplitude of the electrical signal generated at this time is recorded.

[0043] According to the above-mentioned recorded electrical signal amplitudes when the light intensity is maximum and minimum, the corresponding relationship of "detection light intensity-electrical signal amplitude" of the currently used optical sensor 1 can be obtained, that is, the calibration of the optical sensor 1 is completed, which is conducive to improving the detection accuracy.

[0044] 2. Shading The optical sensor 1 works in the open state (eg Figure 1-2 ) and detection status (as shown Figure 4 as shown).

[0045] When the optical sensor 1 is working in the open state, the growth state of the microalgae is not detected, and the light source 20 does not emit reference light. At this time, the active rotor 41 and the passive rotor 42 are close together, and a large open space is formed between the transmitting window 112 and the receiving window 122, so that the culture algae solution (including microalgae cells, water, culture medium, etc.) can be easily placed in the open space.

[0046] At a certain moment, the optical sensor 1 needs to switch from the open state to the detection state. At this time, the control circuit controls the motor 50 to drive the active rotor 41 to rotate toward the side where the passive rotor 42 is located, so that the active rotor 41 pushes the passive rotor 42 to rotate synchronously until the passive rotor 42 is pushed to a preset position (will not cover any position of the optical window) and stops, and then the motor 50 drives the active rotor 41 to rotate a certain angle in the opposite direction, and is spaced from the passive rotor 42. In this way, the open space between the transmitting window 112 and the receiving window 122 is reduced. At this time, the cultured algae liquid in the open space is not easy to circulate with the external cultured algae liquid compared to the open state. And at this time, the passive rotor 42 can also block external light (light other than the reference light emitted by the light source 20) to a certain extent to reduce noise interference.

[0047] 3. Detection of growth status: During the detection of microalgae cell growth information, the active rotor 41 and the passive rotor 42 remain stationary, and at this time, the transmitting window 112 and the receiving window 122 are completely exposed relative to the active rotor 41 and the passive rotor 42. The control circuit transmits a control signal to the light source 20, driving the light source 20 to simultaneously or time-sharingly emit the first reference light and / or the second reference light. After the first reference light and / or the second reference light pass through the culture algae solution (including microalgae cells, water, culture medium, etc.), they are horizontally directed to the receiving window 122 as the first detection light and / or the second detection light. The receiver 30 receives the first detection light and / or the second detection light from the receiving window 122, performs photoelectric conversion, and outputs a corresponding electrical signal. The control circuit calculates the corresponding growth data (including the cell dry weight, pigment content, cell wall component content, cell membrane and other component content of the microalgae cells, etc.) according to the electrical signal, and transmits it to an external device through a signal line 60.

[0048] 4. Optical window (transmitting window 112 and receiving window 122) self-cleaning: Since the optical sensor 1 is continuously immersed in the microalgae culture solution during operation, as the microalgae cells grow, the microalgae cells, biofilms, sediments and other particles may adhere to and accumulate on the first surface 111, the second surface 121 and the receiving space 14, so that the transmitting window 112 and the receiving window 122 are blocked, or the light propagation path is distorted, thereby affecting the detection accuracy. Therefore, in this embodiment, the motor 50 drives the active rotor 41 to rotate around the rotation axis L at a fixed time. Since the two ends of the active rotor 41 contact the first surface 111 and the second surface 121 respectively, when the active rotor 41 rotates around the rotation axis, the active rotor 41 rubs against the first surface 111 and the second surface 121, and the microalgae cells, biofilms, sediments and other particles attached to the first surface 111 and the second surface 121 can be wiped off, and the microalgae cells, biofilms, sediments and other particles in the receiving space 14 can also be cleaned, so as to clean the optical window and the receiving space 14, which is conducive to ensuring that the optical sensor 1 can provide accurate and reliable data for a long time even in a harsh underwater environment.

[0049] As in the optical sensor 1 described above in the present application, the light source 20 emits a first reference light and a second reference light of different wavelengths to detect the growth information of photosynthetic organisms based on the reference lights of different wavelengths. Since reference lights of different wavelengths have different optical properties, the different growth information of photosynthetic organisms detected by the reference lights of different wavelengths are integrated to make the detection data more accurate. In this embodiment, the first reference light is an infrared light of a wavelength of 940nm, and the second reference light is a light of a wavelength of 450nm. The reference lights of the above two wavelengths can enable the optical sensor to detect the content of pigments, cell walls or cell membranes, and other components. The growth state (chlorophyll content) and cell concentration of the cells can be inferred based on the pigments, and the cell density can be inferred based on the cell structure components.

[0050] Moreover, in this embodiment, the positive projection of the receiving window 122 on the first surface 111 completely covers the transmitting window 112, that is, the transmitting window 112 is arranged directly opposite to the receiving window 122. The first reference light and the second reference light emitted from the transmitting window 112 can be horizontally emitted to the receiving window as the first detection light and the second detection light after passing through the light and the biological, which is beneficial to simplify the optical path and reduce light loss.

[0051] Furthermore, in this embodiment, the optical sensor 1 also includes a rotor assembly 40, and the rotor assembly 51 includes an active rotor 41 and a passive rotor 42 that are separately arranged. By driving the active rotor 41 and the passive rotor 42 to rotate, and setting the movement process of the active rotor 41 and the passive rotor 42, the optical sensor 1 can also achieve self-calibration, light shielding and self-cleaning functions when immersed in the culture algae liquid. In this way, the optical sensor 1 can be used in the photosynthetic organism culture system to continuously monitor the growth of photosynthetic organisms for a long time, which is particularly important for the photosynthetic organism culture system with constant turbidity and continuous culture. And by connecting external devices through signal lines, it is also possible to remotely control the operation of the optical sensor 1 and remotely obtain the growth information of photosynthetic organisms.

[0052] The present application also provides a method for monitoring the growth of photosynthetic organisms, which is applied to the control circuit of the optical sensor 1. Figure 5 , the photosynthetic organism growth monitoring method comprises: Step S1, determining an absorption spectrum curve according to the type of photosynthetic organism; Step S2, controlling the motor to drive the active rotor to rotate so that the light-transmitting portion of the active rotor completely covers the transmitting window and the receiving window, so as to calibrate the optical sensor; Step S3, controlling the motor to drive the active rotor to drive the passive rotor to rotate synchronously, and then controlling the motor to drive the active rotor to rotate in the opposite direction, so as to switch the optical sensor to a detection state; Step S4, controlling the light source to emit the first reference light and the second reference light; Step S5, controlling the receiver to receive the first detection light and the second detection light through the receiving window, and receiving an electrical signal from the receiver, wherein the electrical signal is generated according to the first detection light and the second detection light; Step S6, removing noise from the electrical signal; Step S7, based on the absorption spectrum curve, obtaining the growth information of the photosynthetic organism according to the electrical signal.

[0053] In this embodiment, after step S6, the following steps are further included: Step S8, determining whether the cleaning time has arrived.

[0054] If the judgment in step S8 is yes, then step S9 is executed: the motor is controlled to drive the active rotor to rotate in two directions to perform self-cleaning.

[0055] If the result of step S8 is no, step S10 is executed: the motor is controlled to drive the active rotor to drive the passive rotor to rotate until the optical sensor is switched to the open state.

[0056] After the optical sensor is switched to the open state, it may be switched to the detection state again for detection after a preset time interval, that is, step S3 is executed again.

[0057] It should be understood that the above step numbers are not used to limit the order in which the steps are executed.

[0058] The photosynthetic organism growth monitoring method based on the optical sensor 1 described above in the present application can achieve all the beneficial effects of the optical sensor 1 described above. On this basis, the photosynthetic organism growth monitoring method is particularly suitable for a photosynthetic organism cultivation system with constant turbidity and continuous cultivation, and continuously monitors and outputs the growth data of photosynthetic organisms during the photosynthetic organism cultivation process.

[0059] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. An optical sensor, characterized in that: Used to monitor the growth information of photosynthetic organisms; The optical sensor comprises: A main body is formed with a transmitting window and a receiving window which are arranged oppositely and at intervals; a light source, located in the main body, for emitting a first reference light and a second reference light having different wavelengths through the emission window; a receiver, located in the main body, for receiving, through the receiving window, a first detection light generated by the first reference light passing through the photosynthetic organism, and for receiving, through the receiving window, a second detection light generated by the second reference light passing through the photosynthetic organism, and generating an electrical signal according to the first detection light and the second detection light; and The control circuit is electrically connected to the light source and the receiver, and is used to receive the electrical signal and obtain the growth information of the photosynthetic organism based on the electrical signal.

2. The optical sensor according to claim 1, wherein: The first reference light is infrared light, and the wavelength of the second reference light is 450 nm.

3. The optical sensor according to claim 2, characterized in that The wavelength of the first reference light is 940 nm.

4. The optical sensor according to claim 1, wherein: Also included is a rotor assembly, which is movably connected to the main body and is located between the transmitting window and the receiving window; The rotor assembly is rotatable around a rotation axis, and the rotation axis is perpendicular to the transmitting window and the receiving window.

5. The optical sensor according to claim 4, characterized in that The optical sensor further comprises a motor fixedly disposed on the main body, the motor being electrically connected to the control circuit, and the rotor assembly comprising a separate active rotor and a passive rotor; The active rotor is connected to the motor, and the motor is used to drive the active rotor to rotate around the rotation axis. The passive rotor can rotate synchronously with the active rotor under the push of the active rotor.

6. The optical sensor according to claim 5, characterized in that The main body has a first surface and a second surface spaced apart in parallel, the emission window is formed on the first surface, the receiving window is formed on the second surface, and the rotation axis is perpendicular to the first surface and the second surface; Both ends of the driving rotor and the driven rotor are in contact with the first surface and the second surface, respectively.

7. The optical sensor according to claim 6, characterized in that The active rotor includes a light-shielding portion and a light-transmitting portion, wherein the light-transmitting portion is embedded in the light-shielding portion, and both ends of the light-transmitting portion contacting the first surface and the second surface are exposed relative to the light-shielding portion, and both ends of the light-transmitting portion contact the first surface and the second surface respectively.

8. The optical sensor according to claim 6, wherein: The orthographic projection of the receiving window on the first surface completely covers the transmitting window.

9. The optical sensor according to claim 6, wherein: The passive rotor is made of light-shielding material.

10. The optical sensor according to any one of claims 1 to 9, characterized in that: The growth information includes one or any combination of the cell dry weight, pigment content, cell wall component content, and cell membrane component content of the photosynthetic organism.

11. The optical sensor according to any one of claims 1 to 9, characterized in that: It also includes a signal line which is fixedly arranged on the main body and electrically connected to the control circuit.

12. A method for monitoring the growth of photosynthetic organisms, characterized in that: Applicable to the optical sensor as claimed in claim 1; The photosynthetic organism growth monitoring method comprises: Controlling the light source to emit a first reference light and a second reference light; controlling a receiver to receive the first detection light and the second detection light through the receiving window, and receiving an electrical signal from the receiver, wherein the electrical signal is generated according to the first detection light and the second detection light; Based on a preset absorption spectrum curve, the growth information of the photosynthetic organism is obtained according to the electrical signal.

13. The method for monitoring the growth of photosynthetic organisms according to claim 12, wherein: The optical sensor further comprises a motor fixedly disposed on the main body and a rotor assembly located between the transmitting window and the receiving window; After the step of receiving the electrical signal from the receiver, the photosynthetic organism growth monitoring method further comprises: The motor is controlled to drive the rotor assembly to rotate to perform self-cleaning, and / or the motor is controlled to drive the rotor assembly to rotate to switch the optical sensor to an open state.

14. The method for monitoring the growth of photosynthetic organisms according to claim 13, wherein: The rotor assembly includes an active rotor, and the active rotor includes a light-transmitting portion; The photosynthetic organism growth monitoring method further includes, before the step of controlling the light source to emit the first reference light and the second reference light: The motor is controlled to drive the active rotor to rotate so that the light-transmitting portion completely covers the transmitting window and the receiving window, so as to calibrate the optical sensor.

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