Balanced detector and data measurement method and system

Abstract

The invention provides a balance detector and a data measurement method and system. The balance detector provided by the invention comprises a photoelectric module, a gating integral amplification module and an analog-to-digital conversion module. The photoelectric module comprises a first photoelectric detection chip and a second photoelectric detection chip and is used for generating a first current and a second current and generating a current difference; the gating integral amplification module is used for acquiring integral time and integrating the current difference according to the integral time to obtain first voltage data; and the analog-to-digital conversion module is used for converting the first voltage data into light intensity data in a digital form. Therefore, the balance detector performs integration on the current difference according to the integration time, the difference value between the integration time and the pulse width of the optical pulse signal is smaller than the preset threshold value, integration in the time range of the pulse width can be ensured as much as possible, integration on noise beyond the time of the pulse width is effectively reduced, and therefore the measurement error is reduced.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technology, and in particular to a balanced detector, a data measurement method and a system. Background Art

[0002] Balanced detectors are mainly used to detect various weak signals. For example, in photoelectric detection, the two light sources to be compared are illuminated on two photodiodes connected in series, so as to compare and measure the difference in light intensity of the two light sources and achieve high-precision light intensity measurement.

[0003] In existing solutions, balanced detectors often have noise when measuring data, resulting in large measurement errors. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a balanced detector, a data measurement method and a system to effectively reduce the measurement error of the balanced detector.

[0005] To achieve the above objectives, the present application discloses the following technical solutions:

[0006] In a first aspect, the present application provides a balanced detector, comprising: a photoelectric module, a gated integral amplifier module, and an analog-to-digital conversion module;

[0007] The optoelectronic module comprises a first optoelectronic detection chip and a second optoelectronic detection chip;

[0008] The first photodetection chip is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal;

[0009] The second photodetection chip is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal;

[0010] The photovoltaic module is further configured to generate a current difference according to the first current and the second current;

[0011] The gated integral amplifier module is used to obtain an integral time, and integrate the current difference according to the integral time to obtain first voltage data; wherein a first difference between the integral time and a pulse width of the first optical pulse signal, and a second difference between the integral time and a pulse width of the second optical pulse signal are both less than a preset threshold;

[0012] The analog-to-digital conversion module is used to convert the first voltage data into light intensity data in digital form.

[0013] Optionally, the balanced detector further includes: a transimpedance amplification module;

[0014] The transimpedance amplification module is used to receive the first voltage data sent by the gated integral amplification module, convert the first voltage data into the second voltage data, and send the second voltage data to the analog-to-digital conversion module;

[0015] The analog-to-digital conversion module is specifically used to convert the second voltage data into light intensity data in digital form.

[0016] Optionally, the balanced detector further comprises: a delay module;

[0017] The delay module is used to obtain the delay time;

[0018] The gated integral amplifier module is further used to integrate the current difference according to the delay time and the integration time to obtain the first voltage data.

[0019] Optionally, the analog-to-digital conversion module is further used to obtain a light source identifier, where the light source identifier corresponds to the light intensity data;

[0020] The analog-to-digital conversion module is further used to send the light intensity data and the light source identification corresponding to the light intensity data to the terminal device, so that the terminal device can distinguish the light sources corresponding to different light intensity data.

[0021] Optionally, the analog-to-digital conversion module is further used to store the light intensity data in a memory and count the amount of the light intensity data;

[0022] The analog-to-digital conversion module is also used to obtain a preset collection number;

[0023] The analog-to-digital conversion module is further used to package the light intensity data in the memory to obtain first packaged data when determining that the number of the light intensity data reaches the preset collection number;

[0024] The analog-to-digital conversion module is also used to send the first packaged data to the terminal device.

[0025] Optionally, the first photodetection chip and the second photodetection chip both include photodiodes.

[0026] In a second aspect, the present application further provides a data measurement method, which is applied to the balanced detector according to any one of the first aspects, and the method includes:

[0027] receiving a first optical pulse signal, and generating a first current based on the first optical pulse signal;

[0028] receiving a second optical pulse signal, and generating a second current based on the second optical pulse signal;

[0029] generating a current difference according to the first current and the second current;

[0030] Acquire an integration time, integrate the current difference according to the integration time, and obtain first voltage data; wherein a first difference between the integration time and the pulse width of the first optical pulse signal, and a second difference between the integration time and the pulse width of the second optical pulse signal are both less than a preset threshold;

[0031] The first voltage data is converted into light intensity data in digital form.

[0032] Optionally, after obtaining the first voltage data, the method further includes:

[0033] converting the first voltage data into second voltage data;

[0034] The first voltage data is converted into light intensity data in digital form, including: converting the second voltage data into light intensity data in digital form.

[0035] Optionally, the method further includes: obtaining a delay time;

[0036] The step of integrating the current difference according to the integration time to obtain the first voltage data includes: integrating the current difference according to the delay time and the integration time to obtain the first voltage data.

[0037] In a third aspect, the present application further provides a data measurement system, the system comprising: a pulse transmitter, a balanced detector and a terminal device;

[0038] The pulse transmitter is used to generate a first optical pulse signal and a second optical pulse signal, and send the first optical pulse signal and the second optical pulse signal to the balanced detector;

[0039] The balanced detector is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal;

[0040] The balanced detector is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal;

[0041] The balance detector is used to generate a current difference according to the first current and the second current;

[0042] The balance detector is used to obtain an integration time, and integrate the current difference according to the integration time to obtain first voltage data;

[0043] The balanced detector is used to convert the first voltage data into light intensity data in digital form, and send the light intensity data to the terminal device;

[0044] The terminal device is used to receive the light intensity data.

[0045] A balanced detector provided by the present application includes a photoelectric module, a gated integral amplifier module and an analog-to-digital conversion module. The photoelectric module includes a first photoelectric detection chip and a second photoelectric detection chip; the first photoelectric detection chip is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal; the second photoelectric detection chip is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal; the photoelectric module is also used to generate a current difference according to the first current and the second current; the gated integral amplifier module is used to obtain an integration time, integrate the current difference according to the integration time, and obtain a first voltage data; wherein the first difference between the integration time and the pulse width of the first optical pulse signal, and the second difference between the integration time and the pulse width of the second optical pulse signal are both less than a preset threshold; the analog-to-digital conversion module is used to convert the first voltage data into light intensity data in digital form. The above-mentioned balanced detector integrates the current difference according to the integration time, and the difference between the integration time and the pulse width of the optical pulse signal is less than the preset threshold, which can ensure that the integration is performed within the time range of the pulse width as much as possible, effectively reducing the integration of noise outside the time of the pulse width, thereby reducing the measurement error. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and a person skilled in the art can also obtain other drawings based on these drawings.

[0047] Figure 1 It is a schematic diagram of the integration time of a balanced detector in the prior art;

[0048] Figure 2 A structural schematic diagram of a balanced detector provided in an embodiment of the present application;

[0049] Figure 3 A schematic diagram of an integration time provided in an embodiment of the present application;

[0050] Figure 4 A schematic diagram of the structure of another balanced detector provided in an embodiment of the present application;

[0051] Figure 5 A schematic diagram of a balanced detector circuit provided in an embodiment of the present application;

[0052] Figure 6A schematic diagram of a use framework of a balanced detector provided in an embodiment of the present application;

[0053] Figure 7 A schematic diagram of a total delay time provided in an embodiment of the present application;

[0054] Figure 8 A flow chart of a data measurement method provided in an embodiment of the present application;

[0055] Fig. 9 A schematic diagram of the structure of a data measurement system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] To facilitate understanding of the technical solution provided by this application, the background technology involved in this application will be described below.

[0058] At present, balanced detectors often have noise in the process of measuring data, and the measurement error is large. It is understandable that the light pulse signal appears at a certain frequency, and the photodetection chip in the balanced detector will also output dark current when there is no light irradiation. The pulse width of the light pulse signal is very short, and the time interval between pulses is very long. At present, the balanced detector will integrate for a long time and output all the dark current, which results in dark noise accumulated most of the time in this case, causing the noise to increase. Figure 1 As shown, Figure 1 The diagram is a schematic diagram of the integration time of a balanced detector in the prior art, where the horizontal axis t represents time and the vertical axis E represents the electric field intensity. The range of the integration time T is much larger than the pulse width of the optical pulse signal. In the prior art, the balanced detector will continuously integrate multiple optical pulse signals.

[0059] Based on this, the present application provides a balanced detector, including a photoelectric module, a gated integral amplifier module and an analog-to-digital conversion module. The photoelectric module includes a first photoelectric detection chip and a second photoelectric detection chip; the first photoelectric detection chip is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal; the second photoelectric detection chip is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal; the photoelectric module is also used to generate a current difference according to the first current and the second current; the gated integral amplifier module is used to obtain the integration time, integrate the current difference according to the integration time, and obtain the first voltage data; wherein the first difference between the integration time and the pulse width of the first optical pulse signal, and the second difference between the integration time and the pulse width of the second optical pulse signal are both less than a preset threshold; the analog-to-digital conversion module is used to convert the first voltage data into light intensity data in digital form. The above-mentioned balanced detector integrates the current difference according to the integration time, and the difference between the integration time and the pulse width of the optical pulse signal is less than the preset threshold, which can ensure that the integration is performed within the time range of the pulse width as much as possible, effectively reducing the integration of noise outside the time of the pulse width, thereby reducing the measurement error.

[0060] To facilitate understanding of the technical solution provided by the present application, a balanced detector provided by the present application will be described below in conjunction with the accompanying drawings. Figure 2 , which is a schematic diagram of the structure of a balanced detector provided in an embodiment of the present application, such as Figure 2 As shown, the balanced detector includes a photoelectric module 201 , a gated integral amplifier module 202 and an analog-to-digital conversion module 203 .

[0061] The optoelectronic module 201 includes a first optoelectronic detection chip and a second optoelectronic detection chip.

[0062] The first photodetection chip is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal. The second photodetection chip is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal.

[0063] In the embodiment of the present application, the optoelectronic module includes two optoelectronic detection chips, namely a first optoelectronic detection chip and a second optoelectronic detection chip. In the present application, the optoelectronic detection chip can receive the optical pulse signal, thereby converting the optical pulse signal into a current signal.

[0064] The present application does not limit the specific content of the photodetection chip. As an example, the first photodetection chip and the second photodetection chip both include a photodiode. It is understandable that the present application can better realize the conversion of the optical pulse signal into current through the photodiode.

[0065] The photovoltaic module 201 is further configured to generate a current difference according to the first current and the second current.

[0066] In the embodiment of the present application, after the first current and the second current are obtained, the difference between the first current and the second current is calculated to obtain the current difference.

[0067] The gated integral amplifier module 202 is used to obtain the integration time, integrate the current difference according to the integration time, and obtain the first voltage data; wherein the first difference between the integration time and the pulse width of the first optical pulse signal, and the second difference between the integration time and the pulse width of the second optical pulse signal are both less than a preset threshold.

[0068] In the present application, the current difference can be converted into a voltage for output through a gated integral amplifier module. It can be understood that the pulse width refers to the duration of a single optical pulse signal, and the pulse width of the first optical pulse signal and the pulse width of the second optical pulse signal determine the pulse width of the current difference. In the embodiment of the present application, the pulse widths of the first optical pulse signal and the second optical pulse signal are the same, that is, the pulse width of the current difference to be integrated is also the same as the pulse widths of the first optical pulse signal and the second optical pulse signal.

[0069] In the present application, the difference between the integration time and the pulse width of the optical pulse signal is less than the preset threshold value, so that the integration can be performed within the time range of the pulse width as much as possible. Figure 3 As shown, Figure 3 A schematic diagram of an integration time provided in an embodiment of the present application, where the difference between the integration time T and the pulse width is less than a preset threshold, can effectively reduce the integration of noise outside the pulse width, thereby reducing the measurement error. As a possible implementation, the integration time in the present application will be greater than the pulse width to ensure that the data of a single optical pulse signal can be fully acquired.

[0070] The analog-to-digital conversion module 103 is used to convert the first voltage data into light intensity data in digital form.

[0071] In the embodiment of the present application, an analog-to-digital conversion (ADC) module is also integrated in the balanced detector, which can convert the first voltage into light intensity data in digital form.

[0072] In the embodiment of the present application, the difference between the integration time and the pulse width of the optical pulse signal is less than a preset threshold value, which can ensure that the integration is performed within the time range of the pulse width as much as possible, effectively reducing the integration of noise outside the time of the pulse width, thereby reducing the measurement error. In addition, by integrating an analog-to-digital conversion module inside the balanced detector, the present application also avoids the need for an external analog-to-digital converter to obtain the required value, thereby reducing the cost of data measurement.

[0073] As a possible implementation, Figure 4 As shown, Figure 4This is a schematic diagram of the structure of another balanced detector provided in an embodiment of the present application. The balanced detector provided in the present application further includes a transimpedance amplification module 204 .

[0074] The transimpedance amplification module 204 is used to receive the first voltage data sent by the gated integral amplification module, convert the first voltage data into second voltage data, and send the second voltage data to the analog-to-digital conversion module.

[0075] In the embodiment of the present application, the balanced detector is also integrated with an analog-to-digital conversion module. After the gated integral amplifier module generates the first voltage data, the gated integral amplifier module sends the first voltage data to the transimpedance amplifier module. The transimpedance amplifier module can convert the first voltage data into second voltage data, and send the second voltage data to the analog-to-digital conversion module.

[0076] Thus, the analog-to-digital conversion module 203 is specifically used to convert the second voltage data into light intensity data in digital form.

[0077] It can be understood that in the embodiment of the present application, the second voltage data is obtained by converting the first voltage data obtained by the gated integrating amplifier to better match the working range of the analog-to-digital conversion module, thereby improving the accuracy of the acquired light intensity data.

[0078] As a possible implementation manner, the balanced detector further includes: a delay module.

[0079] Delay module, used to obtain delay time.

[0080] The gated integral amplifier module 202 is further used to integrate the current difference according to the delay time and the integration time to obtain the first voltage data.

[0081] In the embodiment of the present application, the delay module also obtains the delay time and sends the delay time to the gated integral amplifier module, so that the gated integral amplifier module can integrate the current difference according to the delay time and the integration time to obtain the first voltage data.

[0082] It is understandable that the delay time is used to control when the gated integral amplifier module starts working. The present application does not limit the specific method of integrating the current difference according to the delay time and the integration time to obtain the first voltage data. As an example, the gated integral amplifier module can determine the execution time according to the current time and the delay time of the balance detector. When the system time of the balance detector reaches the execution time, the current difference starts to be integrated. The current time indicates the time when the gated integral amplifier module receives the delay time. The gated integral amplifier module determines the time point when the delay time is received as the current time, and starts integration at the time point after the current time plus the delay time, and ends the integration of the current difference after the integration time.

[0083] The present application does not limit the specific value of the delay time, and the size of the specific value can be determined according to actual needs.

[0084] As a possible implementation method, the present application takes into account that the propagation of the optical pulse signal requires a certain amount of time. The present application can determine the delay time based on the propagation time of the optical pulse signal. By setting the delay time, the pulse width of the optical pulse signal can be better within the integration time window of the balanced detector, thereby better reducing the impact of dark current and better reducing noise.

[0085] As a possible implementation manner, the analog-to-digital conversion module 203 is also used to obtain a light source identifier, which corresponds to the light intensity data.

[0086] The analog-to-digital conversion module 203 is further used to send the light intensity data and the light source identification corresponding to the light intensity data to the terminal device, so that the terminal device can distinguish the light sources corresponding to different light intensity data.

[0087] In an embodiment of the present application, the analog-to-digital conversion module can also obtain a light source identification, which corresponds to the light intensity data. It can be understood that the light source identification is used to indicate whether the light intensity data is generated after being irradiated by a certain light source. The present application can effectively use the light source identification to compare different light intensity data under the irradiation of a certain light source.

[0088] The present application does not limit the specific method of obtaining the light source identification. As an example, the present application can generate the light source identification through a chopper, so that the chopper can send the light source identification to the analog-to-digital conversion module. It can be understood that the first light pulse signal and the second light pulse signal in the embodiment of the present application can be detection light. The present application can use different light sources to illuminate the sample in order to detect the properties of different samples. The detection light is generated after the light source has passed through a certain sample. In the present application, some light sources used to illuminate the sample several times can be shielded by a chopper to determine whether the light intensity data has been illuminated by a certain light source.

[0089] It can be understood that the chopper is similar to a fan. When light passes through this rotating fan, there are two situations: being blocked and passing. By giving the chopper a frequency and letting the chopper rotate at this frequency, the chopper determines whether to perform light shielding processing this time according to the frequency of rotation, so that a light source identification can be generated and sent to the analog-to-digital conversion module. For example, the present application can use a chopper to shield the even-numbered light pulses in the light source used to irradiate the sample, so that the chopper can generate a light source identification when the light pulses of the light source are even numbers, indicating that the light intensity data generated this time does not involve the participation of the light source, and generates a light source identification when the light pulses of the light source are odd numbers, indicating that the light intensity data generated this time involves the participation of the light source.

[0090] For easier understanding, the following will use the terahertz (THZ) experiment as an example for detailed explanation.

[0091] As a possible implementation manner, the analog-to-digital conversion module 203 is further configured to store the light intensity data in a memory and count the amount of the light intensity data.

[0092] The analog-to-digital conversion module 203 is also used to obtain a preset number of acquisitions.

[0093] The analog-to-digital conversion module 203 is further used to package the light intensity data in the memory to obtain first packaged data when the number of light intensity data reaches a preset collection number.

[0094] The analog-to-digital conversion module 203 is further configured to send the first packaged data to the terminal device.

[0095] In an embodiment of the present application, a preset number of light intensity data to be collected can also be set, so that the analog-to-digital conversion module can store multiple light intensity data in the memory, and then package them together and send them to the terminal device.

[0096] The present application does not limit the specific content of the memory. As an example, the memory may include a double data rate synchronous dynamic random access memory (Double Data Rate, DDR). The present application can store multiple light intensity data at one time and then send them uniformly, reducing the burden on the network and improving the efficiency of data acquisition.

[0097] As a possible implementation, the present application can modify the integration time and the delay time. By flexibly controlling the size of the integration time, the present application can adapt to different signals with different pulse widths, and can effectively collect different signals with different pulse widths. It is understandable that the time intervals between pulses of pulse signals with different frequencies are different. The present application can adapt to pulse signals with different frequencies by controlling the delay time.

[0098] The present application is further described below in conjunction with specific application scenarios. The present application embodiment uses a balanced detector to perform a THz experiment as an example to illustrate the solution of the present application. Figure 5 , Figure 6 shown.

[0099] in Figure 5A schematic diagram of a balanced detector circuit is provided for an embodiment of the present application, wherein the front end of the balanced detector is two photodiodes of exactly the same model, and two different beams of light are respectively irradiated on the upper and lower photodiodes, and the photodiodes will generate current after being illuminated. The output from the two photodiodes is the current difference I1-I2 of the two photodiodes, and the current difference I1-I2 is converted into a voltage output through a gated integral amplifier. The present application can set the integration time and delay time of the gated integral amplifier through the system chip SOC, field programmable gate array FPGA, etc. Figure 5 As shown, when S1 is turned on, it means the integration starts; when S1 is turned off, it means the charge is released and the integration stops. This application only needs to turn on S1 when the light pulse signal arrives and generates current on the photodiode, and turn it off when there is no light pulse signal to achieve integration of only the light pulse signal. The gated integrating amplifier will output the first voltage data V1 for integration, and the transimpedance amplifier will perform voltage operation on the first voltage data V1 output by the gated integrating amplifier to convert it into the second voltage data V2 to match the working range of the analog-to-digital converter. The signal of the transimpedance amplifier is output to the analog-to-digital converter. Under the instruction control of the fully programmable system on chip ZYNQ, the calculated second voltage data can be converted into light intensity data in digital form through the analog-to-digital converter and cached in DDR.

[0100] In addition, the present application can also set a corresponding number of collections. When the present application determines that the light intensity data cached in the DDR reaches the number of collections, the light intensity data in the DDR can be packaged into a UDP (User Datagram Protocol) datagram format and sent to the terminal device PC. The sent data is then processed by the terminal device PC and displayed as individual light intensity data.

[0101] as follows Figure 6 As shown, Figure 6 A schematic diagram of the use framework of a balanced detector provided in an embodiment of the present application, wherein the pulsed laser emitted by the pulsed laser 610 is divided into two beams after passing through the beam splitter 601: a pulsed laser 611 and a pulsed laser 612. The pulsed laser 611 generates a detection light 613 after passing through the detection light generating module 602, and the detection light 613 hits the electro-optical crystal 607. The pulsed laser 612 generates a THz light 614 after passing through the THz light generating module 603. The THz light 614 generates chopped THz light 615 after passing through the chopping device 604. The chopped THz light 615 hits the electro-optical crystal 607 after passing through the parabolic mirror 605 and the parabolic mirror 606; the THz light 615 will hit the electro-optical crystal 607 slightly earlier than the detection light 613.

[0102] If the chopper 604 shields the THz light, resulting in the absence of THz light 615, the electro-optic crystal (EOcrystal) 607 will not be modulated, and the output linear polarized light 616 will generate circular polarized light 617 after passing through the quarter wave plate (QWP) 608. The circular polarized light 617 will generate two linear polarized lights 618 and 619 with perpendicular polarization directions and equal intensities after passing through the polarization beam splitter (PBS) 609. The linear polarized lights 618 and 619 are respectively irradiated on two series photodiodes of a balanced detector (balanced detector) 620. The linear polarized light 618 and the linear polarized light 619 can be understood as the first optical pulse signal and the second optical pulse signal mentioned above.

[0103] If there is THz light 615, the electro-optical crystal 607 is modulated, and the linear polarized light 616 after the detection light 613 passes through the electro-optical crystal 607 generates elliptically polarized light 617 after passing through the quarter wave plate 608. At this time, the intensities of the two linear polarized lights 618 and 619 with polarizations perpendicular to each other generated after passing through the polarization beam splitter 609 are no longer equal. The balanced detector 620 will measure the intensity difference between the two light beams, process it to obtain light intensity data in digital form, and then transmit it to the terminal device 621 through the network 650.

[0104] In this application, when the laser 610 is about to emit a laser pulse, the laser will first generate an electric pulse trigger and transmit it to the balanced detector through the BNC line 640. As a possible implementation method, in this application, the electric pulse trigger will detect the light pulse t1 time in advance, and inform the balanced detector to work. The reason for the advance is that this application also takes into account the propagation of the optical pulse signal, the propagation of the electric pulse trigger, and the response time of the balanced detector to the processing of the electric pulse signal. Figure 7 As shown, Figure 7 A schematic diagram of a total delay time provided in an embodiment of the present application. Figure 7 The t2 in the figure represents the total delay time, which is the delay time + the propagation time of the trigger circuit + the response time of the balanced detector - the propagation time of the optical pulse signal. It is understandable that the required delay time can be flexibly set in the present application, so that the final total delay time t2 = the advance emission time t1. After the balanced detector receives the laser trigger, it will wait for the corresponding delay time before starting to work. The ultimate goal is to make Figure 7The start time of integration in the balanced detector is aligned with the time node of the detection light pulse, so that the duration of the detection light pulse can fall exactly within the integration time window of the balanced detector, that is, the delay trigger is aligned with the detection light pulse, so that the influence of dark current is minimized to achieve the lowest noise. When the balanced detector receives the trigger, the integration start time is obtained through the delay module, and then the delay trigger containing the integration start time is passed to the gated integration amplifier module. The balanced detector will Figure 5 When S1 in the diode is opened, the gated integrating amplifier integrates the current from the diode.

[0105] The application uses an integrating amplifier, so the magnitude of its output voltage is proportional to time, that is, when the photodiode has current output, the longer S1 is open, the higher its output voltage. The length of time S1 is open is consistent with the length of time a detection light pulse is added to the response time of the detection chip (here, the photodiode). The length of time S1 is open is called the integration time. The application converts a light pulse with a peak value into a voltage that gradually rises to a flat state through an integrating amplifier. The advantage of doing so is that it is conducive to the subsequent ADC (analog-to-digital converter) to collect it. The application only needs to sample it when the voltage data rises to a point close to the flat state to complete the data collection. After the time S1 is open reaches the integration time, it will be closed until the next trigger arrives, and S1 will be opened again, and the above process will be repeated in this way. Trigger is an electrical signal transmitted from the pulse laser 610 to the balanced detector 620 through the BNC line 640, and its function is to inform the balanced detector that the light pulse signal is coming and prepare to start integration.

[0106] In addition, if Figure 6As shown, the chopper device 604 is also connected to the balanced detector 620 via a BNC line 630. The balanced detector 620 can be connected to the chopper device 604 in turn through an optical coupler isolation chip and a snap-fit ​​connector (Bayonet Nut Connector, BNC). The use of the optical coupler chip can effectively reduce the interference of the signal of the external circuit on the light intensity detection of the internal circuit. The photocurrent from the photodiode is integrated each time the trigger signal of the pulsed laser is received. In the embodiment of the present application, the chopper device 604 will send a judgment signal, which is the light source identification discussed above. The present application is explained by distinguishing the light intensity data of the sample 607 with terahertz light (THz light) excitation and the light intensity data of the sample 607 without terahertz light excitation. The function of the chopper device 604 is to block light / release light, which can inform the balanced detector 620 whether there is a terahertz light excitation sample 607 at this time. It can be understood that the presence of terahertz light excitation sample 607 means that terahertz light irradiates the sample 607. As an example, when there is terahertz light exciting sample 607, chopping device 604 transmits a high level 1 to balanced detector 620 through BNC line 630 to mark that there is terahertz light in the light intensity data collected this time; when there is no terahertz light exciting sample 607, chopping device 604 transmits a low level 0 to balanced detector 620 through BNC line 630 to mark that there is no terahertz light exciting sample 607 in the light intensity data collected this time. Therefore, the present application can compare the changes in the detected light when there is or is not terahertz light exciting sample (electro-optic crystal) 607 according to whether the light source identification bit corresponding to the light intensity data is high or low.

[0107] See also Figure 8 , Figure 8 A flow chart of a data measurement method provided in an embodiment of the present invention is provided. The method is applied to realize the balanced detector provided in the above embodiment. The method includes:

[0108] S801: Receive a first optical pulse signal, and generate a first current based on the first optical pulse signal; receive a second optical pulse signal, and generate a second current based on the second optical pulse signal;

[0109] S802: generating a current difference according to the first current and the second current;

[0110] S803: Acquire an integration time, and integrate the current difference according to the integration time to obtain first voltage data; wherein a first difference between the integration time and the pulse width of the first optical pulse signal, and a second difference between the integration time and the pulse width of the second optical pulse signal are both less than a preset threshold;

[0111] S804: Convert the first voltage data into light intensity data in digital form.

[0112] As a possible implementation manner, after obtaining the first voltage data, the method further includes:

[0113] converting the first voltage data into second voltage data;

[0114] Then S804 converting the first voltage data into light intensity data in digital form includes: converting the second voltage data into light intensity data in digital form.

[0115] As a possible implementation manner, the method further includes: obtaining a delay time;

[0116] In S803, the current difference is integrated according to the integration time to obtain the first voltage data, including: integrating the current difference according to the delay time and the integration time to obtain the first voltage data.

[0117] As a possible implementation, the method further includes the following steps:

[0118] A light source identification is obtained, where the light source identification corresponds to the light intensity data.

[0119] The light intensity data and the light source identification corresponding to the light intensity data are sent to a terminal device, so that the terminal device can distinguish the light sources corresponding to different light intensity data.

[0120] As a possible implementation manner, the method further includes storing the light intensity data in a memory, and counting the amount of the light intensity data;

[0121] Get the preset number of collections;

[0122] When it is determined that the number of the light intensity data reaches the preset collection number, the light intensity data in the memory is packaged to obtain first packaged data;

[0123] The first packaged data is sent to the terminal device.

[0124] It should be noted that a data measurement method provided in an embodiment of the present application has the technical effects of any of the above embodiments, and the embodiments of the present application are not described in detail here.

[0125] See also Fig. 9 , Fig. 9 This is a structural diagram of a data measurement system provided in an embodiment of the present application. The data measurement system 900 includes a pulse transmitter 901, a balanced detector 902 and a terminal device 903.

[0126] A pulse transmitter 901, configured to generate a first optical pulse signal and a second optical pulse signal, and send the first optical pulse signal and the second optical pulse signal to the balanced detector;

[0127] The balanced detector is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal;

[0128] The balanced detector is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal;

[0129] The balance detector is used to generate a current difference according to the first current and the second current;

[0130] The balance detector is used to obtain an integration time, and integrate the current difference according to the integration time to obtain first voltage data;

[0131] The balanced detector is used to convert the first voltage data into light intensity data in digital form, and send the light intensity data to the terminal device;

[0132] The terminal device is used to receive the light intensity data.

[0133] As a possible implementation manner, the balanced detector is further used to receive the first voltage data sent by the gated integral amplifier module, convert the first voltage data into the second voltage data, and send the second voltage data to the analog-to-digital conversion module;

[0134] The balanced detector is specifically used to convert the second voltage data into light intensity data in digital form.

[0135] As a possible implementation, the balanced detector is also used to obtain the delay time;

[0136] The balanced detector is further used to integrate the current difference according to the delay time and the integration time to obtain the first voltage data.

[0137] As a possible implementation, the balanced detector is further used to obtain a light source identification, where the light source identification corresponds to the light intensity data;

[0138] The balanced detector is further used to send the light intensity data and the light source identification corresponding to the light intensity data to the terminal device, so that the terminal device can distinguish the light sources corresponding to different light intensity data.

[0139] As a possible implementation, the balanced detector is further used to store the light intensity data in a memory and count the amount of the light intensity data;

[0140] The balanced detector is also used to obtain a preset number of acquisitions;

[0141] The balanced detector is further used to package the light intensity data in the memory to obtain first packaged data when the number of the light intensity data reaches the preset collection number;

[0142] The balance detector is further configured to send the first packaged data to a terminal device.

[0143] It should be noted that a data measurement system provided in an embodiment of the present application has the technical effects of any of the above embodiments, and the embodiments of the present application are not described in detail here.

[0144] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0145] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0146] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A balanced detector, It is characterized in that include: Photoelectric module, gated integral amplifier module and analog-to-digital conversion module; The optoelectronic module comprises a first optoelectronic detection chip and a second optoelectronic detection chip; The first photodetection chip is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal; The second photodetection chip is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal; The photovoltaic module is further configured to generate a current difference according to the first current and the second current; The gated integral amplifier module is used to obtain an integral time, and integrate the current difference according to the integral time to obtain first voltage data; wherein a first difference between the integral time and a pulse width of the first optical pulse signal, and a second difference between the integral time and a pulse width of the second optical pulse signal are both less than a preset threshold; The analog-to-digital conversion module is used to convert the first voltage data into light intensity data in digital form.

2. The balanced detector according to claim 1, It is characterized in that The balanced detector further comprises: a transimpedance amplification module; The transimpedance amplification module is used to receive the first voltage data sent by the gated integral amplification module, convert the first voltage data into second voltage data, and send the second voltage data to the analog-to-digital conversion module; The analog-to-digital conversion module is specifically used to convert the second voltage data into light intensity data in digital form.

3. The balanced detector according to claim 1, It is characterized in that The balanced detector further comprises: a delay module; The delay module is used to obtain the delay time; The gated integral amplifier module is further used to integrate the current difference according to the delay time and the integration time to obtain the first voltage data.

4. The balanced detector according to claim 1, It is characterized in that The analog-to-digital conversion module is further used to obtain a light source identifier, where the light source identifier corresponds to the light intensity data; The analog-to-digital conversion module is further used to send the light intensity data and the light source identification corresponding to the light intensity data to the terminal device, so that the terminal device can distinguish the light sources corresponding to different light intensity data.

5. The balanced detector according to claim 1, It is characterized in that The analog-to-digital conversion module is further used to store the light intensity data in a memory and count the amount of the light intensity data; The analog-to-digital conversion module is also used to obtain a preset collection number; The analog-to-digital conversion module is further used to package the light intensity data in the memory to obtain first packaged data when determining that the number of the light intensity data reaches the preset collection number; The analog-to-digital conversion module is also used to send the first packaged data to the terminal device.

6. The balanced detector according to claim 1, It is characterized in that The first photodetection chip and the second photodetection chip both include photodiodes.

7. A data measurement method, It is characterized in that The method is applied to the balanced detector according to any one of claims 1 to 6, and the method comprises: receiving a first optical pulse signal and generating a first current based on the first optical pulse signal; receiving a second optical pulse signal and generating a second current based on the second optical pulse signal; generating a current difference according to the first current and the second current; Acquire an integration time, integrate the current difference according to the integration time, and obtain first voltage data; wherein a first difference between the integration time and the pulse width of the first optical pulse signal, and a second difference between the integration time and the pulse width of the second optical pulse signal are both less than a preset threshold; The first voltage data is converted into light intensity data in digital form.

8. The method according to claim 7, It is characterized in that After obtaining the first voltage data, the method further includes: converting the first voltage data into second voltage data; The first voltage data is converted into light intensity data in digital form, including: converting the second voltage data into light intensity data in digital form.

9. The method according to claim 7, It is characterized in that The method further comprises: obtaining a delay time; The step of integrating the current difference according to the integration time to obtain the first voltage data includes: integrating the current difference according to the delay time and the integration time to obtain the first voltage data.

10. A data measurement system, It is characterized in that The system comprises: a pulse transmitter, a balanced detector and a terminal device; The pulse transmitter is used to generate a first optical pulse signal and a second optical pulse signal, and send the first optical pulse signal and the second optical pulse signal to the balanced detector; The balanced detector is used to receive a first optical pulse signal and generate a first current based on the first optical pulse signal; The balanced detector is used to receive a second optical pulse signal and generate a second current based on the second optical pulse signal; The balance detector is used to generate a current difference according to the first current and the second current; The balance detector is used to obtain an integration time, and integrate the current difference according to the integration time to obtain first voltage data; The balanced detector is used to convert the first voltage data into light intensity data in digital form, and send the light intensity data to the terminal device; The terminal device is used to receive the light intensity data.

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