Apparatus and method for controlling transport of carriers induced by pulsed laser irradiation

Abstract

The application discloses a kind of pulse laser irradiation induced carrier transport control device and method.The device includes: laser (1), attenuating piece group (2), beam splitter (3), focusing lens (4), line-by-line transfer type area array CCD (5), computer (6), delay controller (7);Line-by-line transfer type area array CCD is connected with delay controller and computer, delay controller is also connected with laser, attenuating piece group, beam splitter, focusing lens are distributed in the light path between laser 1 and line-by-line transfer type area array CCD in common optical axis in sequence;Delay controller, by controlling the delay time between laser output and CCD of laser, adjusts image output result;Laser is as the interference light source of photoelectric detection device, to generate pulse laser in single pulse form, irradiates line-by-line transfer type area array CCD.Application of the present application can be through the control delay time, accurately control the image position of crosstalk line in the image of CCD.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric detection devices, and particularly relates to a device and method for controlling carrier transport induced by pulsed laser irradiation. BACKGROUND

[0002] As a typical photoelectric detection device with a Metal Oxide Semiconductor (MOS) structure as a basic unit, a Charge Coupled Device (CCD) has the advantages of small volume, light weight, high sensitivity and resolution, low power consumption and low cost, and has been widely used in many fields and become an important photoelectric detection imaging unit. The research on optical protection and damage of the CCD has increasingly become a focus.

[0003] As a strong light source, laser technology has attracted much attention due to the optical imaging interference caused by the irradiation of the laser on the CCD. According to the influence degree, the irradiation of the laser on the CCD is usually divided into two types: laser interference and laser damage. Laser interference mainly refers to the temporary interference phenomena such as saturation, crosstalk and oversaturation caused by the irradiation of the laser on the CCD. When the CCD camera is taking a photo, the output image will contain some interference phenomena such as saturation, crosstalk and oversaturation due to the irradiation of the laser, which temporarily reduces the performance of the photoelectric detector. When the laser irradiation stops, the influence gradually subsides. Laser damage mainly refers to the permanent damage such as deformation, ablation and perforation of the image sensor of the CCD caused by the irradiation of the laser on the CCD. When the laser irradiation stops, the influence cannot be recovered.

[0004] When the laser irradiation causes interference and damage to the CCD, it will have different degrees of influence on the imaging of the CCD. The laser irradiation conditions required for laser interference are more easily met. The laser irradiation condition mainly refers to the laser energy density, and the laser energy density = laser energy / laser spot area on the surface of the CCD. With the increase of the laser energy density from small to large, laser interference occurs first, and then laser damage occurs. Therefore, the interference effect of the laser irradiation on the CCD has also attracted more attention.

[0005] From the existing research, the following new problems in the research on the interference effect of the laser irradiation on the CCD have not been solved:

[0006] 1) Since the peak power of pulsed laser is usually high, the existing research focuses on damage and ignores the research on laser interference effect. The interference effect caused by the pulsed laser irradiation on the CCD has not been further studied;

[0007] 2) The interference process of pulsed laser irradiation on CCD is not clear. Since the pulse width of pulsed laser is much smaller than the integration time of CCD, the interference phenomenon caused by the action time of pulsed laser and imaging process is not clear, and the mechanism of pulsed laser interference process in time history is not clear;

[0008] 3) The transport of photo-generated carriers controlled by pulsed laser is lacking. Due to the transient effect of pulsed laser action, the photo-generated carriers will affect the imaging in spatial scale with the physical transport of imaging process, and the transport control method of photo-generated carriers by pulsed laser has not been proposed. SUMMARY

[0009] The purpose of the present application is to provide a pulsed laser irradiation induced carrier transport control device and method, which can generate laser spot image and / or crosstalk line image at specified pixel coordinate position based on time delay control and pixel position control.

[0010] To achieve the above purpose, the present application provides the following technical scheme:

[0011] According to one aspect of the present application, a pulsed laser irradiation induced carrier transport control device is provided, comprising:

[0012] laser 1, attenuator group 2, beam splitter 3, focusing lens 4, line transfer area array CCD 5, computer 6, delay controller 7, probe 8, energy meter 9; the line transfer area array CCD 5 is connected with the delay controller 7 and the computer 6, the delay controller 7 is also connected with the laser 1, the probe 8 is connected with the energy meter 9, and the attenuator group 2, the beam splitter 3 and the focusing lens 4 are coaxially distributed in sequence on the light path between the laser 1 and the line transfer area array CCD 5;

[0013] The pulsed laser emitted by the laser is attenuated by the attenuator group 2, and then divided into two beams of pulsed laser by the beam splitter 3, the first beam of pulsed laser is used for irradiating the probe 8, and the second beam of pulsed laser is used for irradiating the line transfer area array CCD 5, and the focusing lens 4 is used for focusing the second beam of pulsed laser, so that the second beam of pulsed laser reaches the energy density required for crosstalk phenomenon on the chip surface of the line transfer area array CCD 5;

[0014] The computer 6 is used for parameter setting of the line transfer area array CCD 5, and recording the interference image generated after the pulsed laser irradiates the CCD; the delay controller 7 is used for controlling the timing sequence between the intervention time of the laser 1 and the CCD image acquisition; the laser 1 is used as an interference light source of photoelectric detection device, and generates pulsed laser in the form of single pulse to irradiate the line transfer area array CCD 5; the probe 8 is used for measuring the energy of the first beam of pulsed laser, and the energy meter 9 is used for displaying the measurement value of the energy of the first beam of pulsed laser by the probe 8.

[0015] According to one embodiment of the present application, the number of filters or the transmittance of the attenuating pieces in the attenuating piece set 2 is adjusted according to the laser energy value measured by the energy meter 9, so that the second laser beam reaches the energy density required for generating crosstalk on the chip surface of the line-by-line transfer area array CCD 5 and is lower than the energy density threshold value that can cause damage to the CCD.

[0016] According to one embodiment of the present application, the attenuating piece set comprises a first attenuating piece 21 and a second attenuating piece 22 arranged in sequence along the light path.

[0017] According to one embodiment of the present application, the first attenuating piece 21 and the second attenuating piece 22 are alternately placed at an angle of 0-45° with the light path.

[0018] According to one embodiment of the present application, the pulsed laser is a femtosecond pulsed laser, or a picosecond pulsed laser, or a nanosecond pulsed laser.

[0019] According to one embodiment of the present application, the delay controller 7 sends a TTL level signal to the laser 1, and the laser emits a single-pulse pulsed laser according to the TTL level signal; the delay controller 7 sends a TTL level signal to the line-by-line transfer area array CCD, and the line-by-line transfer area array CCD determines the starting time of operation according to the TTL level signal, so as to collect the laser interference image and record it through the computer.

[0020] According to one embodiment of the present application, the computer is configured to set the integration time of the line-by-line transfer area array CCD and the pulsed laser irradiation position on the surface; obtain the transfer speed of the vertical transfer potential well of the line-by-line transfer area array CCD according to the number of vertical pixels and the integration time; take the quotient of the ordinate of the pulsed laser irradiation position and the transfer speed as the minimum delay time of the crosstalk line, and take the sum of the minimum delay time and the readout time of the line-by-line transfer area array CCD as the maximum delay time of the crosstalk line; determine the required delay time Δt according to the spatial position of the expected crosstalk line image.

[0021] The delay controller is configured to set the delay time Δt between the CCD and the pulsed laser, and control the pulsed laser to irradiate the line-by-line transfer area array CCD according to the delay time; and the computer is configured to collect the readout data of the line-by-line transfer area array CCD, and obtain the expected output image.

[0022] On the other hand, the present application also provides a method for controlling the transport of carriers induced by pulsed laser irradiation based on the above-mentioned device, comprising the following steps:

[0023] setting the integration time of the line-by-line transfer area array CCD and the pulsed laser irradiation position on the surface;

[0024] According to the vertical pixel number and the integral time, the transmission speed of the vertical transmission potential well of the line-by-line transfer type area CCD is obtained;

[0025] The quotient of the longitudinal coordinate of the position irradiated by the pulsed laser and the transmission speed is taken as the minimum delay time of the crosstalk line, and the sum of the minimum delay time and the readout time of the line-by-line transfer type area CCD is taken as the maximum delay time of the crosstalk line;

[0026] The delay time required according to the spatial position of the expected crosstalk line image is determined;

[0027] The delay controller is controlled to set the delay time between the CCD and the pulsed laser, and the pulsed laser is controlled to irradiate the line-by-line transfer type area CCD according to the delay time, so that the expected output image is obtained.

[0028] The delay time required according to the spatial position of the expected crosstalk line image is determined, comprising:

[0029] The abscissa of the position irradiated by the pulsed laser is taken as the abscissa of the crosstalk line; the difference between the required delay time and the minimum delay time is multiplied by the transmission speed to define the transmission distance; the ordinate of the crosstalk line is defined as the difference between the vertical pixel number and the transmission distance; and the required delay time is obtained according to the set ordinate of the crosstalk line and the calculated minimum delay time and transmission speed.

[0030] The delay time required according to the spatial position of the expected crosstalk line image is determined, further comprising the step of determining whether the expected output image of the CCD includes the laser main spot:

[0031] If the expected output image includes the laser main spot and the crosstalk line, the delay time Δt is controlled to be: the minimum delay time Δt start <Δt<integral time T e ;

[0032] If the expected output image does not include the laser main spot but only includes the crosstalk line, the delay time Δt is controlled to be: the integral time T e <Δt<maximum delay time Δt end ;

[0033] If the expected output image only includes the laser main spot, the delay time Δt is controlled to be: 0<Δt<the minimum delay time Δt start ;

[0034] If the expected output image has neither the laser main spot nor the crosstalk line, the delay time Δt is controlled to be: the maximum delay time Δt end <Δt<2*T e .

[0035] The application discloses a device and method for controlling carrier transport induced by pulsed laser irradiation.

[0036] 1. By controlling the time delay between the starting time of the CCD device and the intervention time of the short pulsed laser, the laser irradiation position and the like, the spatial distribution control of the crosstalk phenomenon of the short pulsed laser irradiation photoelectric detection device is realized.

[0037] 2. The control in the time scale can be realized in the order of picoseconds, and the delay controller has a precision of 5 ps, which depends on the control precision of the delay controller.

[0038] 3. The control in the space scale can be realized in the pixel level, and the size of a single pixel in the CCD is about 10 microns, and the size of a single pixel of the CCD used in the embodiment is 6.45 microns.

[0039] 4. Based on the formation mechanism of the short line time-space distribution phenomenon of the crosstalk of the short pulsed laser irradiation photoelectric detection device, the short pulsed laser controlled photo-generated carrier transport can be accurately controlled, and based on the time delay control and the pixel position control, the laser spot image and / or the crosstalk line image can be generated at the specified pixel coordinate position. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which are included to provide a further understanding of the application and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0041] Figure 1 FIG. 1 is a schematic diagram of a device for controlling carrier transport induced by pulsed laser irradiation according to an exemplary embodiment of the application.

[0042] Figure 2 FIG. 2 is a working principle diagram of a line-by-line transfer type area array CCD according to an exemplary embodiment of the application.

[0043] Figure 3 FIG. 3 is a timing diagram of a single pulse loading of a short pulsed laser in a single frame mode of a CCD according to an exemplary embodiment of the application.

[0044] Figure 4 FIG. 4 is a schematic diagram of a method for controlling carrier transport induced by pulsed laser irradiation according to an exemplary embodiment of the application.

[0045] Figure 5is a schematic diagram of a CCD image including a laser spot and a cross-talk line according to an exemplary embodiment of the present application.

[0046] Figure 6 is a schematic diagram of a CCD image including only a laser spot according to an exemplary embodiment of the present application.

[0047] Figure 7 is a schematic diagram of a CCD image including only a cross-talk line according to an exemplary embodiment of the present application.

[0048] Reference numerals:

[0049] 1 - laser; 2 - attenuator set; 3 - beam splitter; 4 - focusing lens; 5 - line- transfer area CCD; 6 - computer; 7 - delay controller; 8 - probe; 9 - energy meter; 21 - first attenuator; 22 - second attenuator. DETAILED DESCRIPTION

[0050] In order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same or similar items with basically the same function and effect. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and do not limit the order. Those skilled in the art can understand that the words "first", "second", etc. do not limit the number and execution order, and the words "first", "second", etc. also do not mean that they are necessarily different.

[0051] It should be noted that in the present application, the words "exemplary" or "for example" are used to represent an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the words "exemplary" or "for example" are intended to present the relevant concept in a specific manner.

[0052] In the present application, "at least one" means one or more, and "multiple" means two or more. The association relationship of the associated objects is described, which means that there can be three relationships, for example, A and / or B, which can represent the following cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. The following at least one (or similar expressions) means any combination of these items, including any combination of single item (or plural items). For example, at least one of a, b or c can represent: a, b, c, a and b, a and c, b and c, or a, b and c, where a, b, c can be singular or plural.

[0053] In the following, embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0054] As Figure 1 shown, a schematic diagram of a carrier transport control device induced by pulsed laser irradiation is given. The carrier transport control device induced by pulsed laser irradiation comprises:

[0055] laser 1, attenuator group 2, beam splitter 3, focusing lens 4, line transfer area array CCD 5, computer 6, delay controller 7, probe 8, energy meter 9. The attenuator group 2 comprises a first attenuator 21 and a second attenuator 22.

[0056] The line transfer area array CCD 5 is connected with the delay controller 7 and the computer 6, the delay controller 7 is also connected with the laser 1, the probe 8 is connected with the energy meter 9, the attenuator group 2, the beam splitter 3 and the focusing lens 4 are sequentially distributed on the light path between the laser 1 and the line transfer area array CCD 5, the attenuator group 2 is located after the laser 1, the beam splitter 3 is located after the attenuator group 2, and the focusing lens 4 is located after the beam splitter 3. The attenuator group 2, the beam splitter 2 and the focusing lens 4 are coaxial with the laser 1, and the probe 8 is also located after the beam splitter 3.

[0057] The beam splitter 3 is used to divide the laser emitted by the laser into two beams, so as to achieve beam splitting of the laser: the first beam is used to irradiate the probe, and the second beam is used to irradiate the line transfer area array CCD 5. The focusing lens 4 is used to focus the laser, so that the laser reaches the energy density required to produce crosstalk on the chip surface of the line transfer area array CCD 5. The probe 8 is used to measure the energy of the first beam, and the attenuator group 2 is adjusted according to the measured laser energy value, the number or transmittance of the attenuator is increased or decreased. The energy meter 9 is used to display the measurement value of the first beam energy measured by the probe 8.

[0058] When the laser emitted by the laser 1 irradiates the line transfer area array CCD 5, the photosensitive area in the pixel of the line transfer area array CCD 5 will perform photoelectric conversion and generate signal charge, the signal charge is transported in the transfer channel of the line transfer area array CCD 5, and finally the signal charge is recognized and converted through the readout end of the line transfer area array CCD 5, and the captured image is output.

[0059] The computer 6 is used for parameter setting of the line transfer area array CCD 5, and recording of the interference image generated after the laser irradiates the CCD. The delay controller 7 is used to control the timing of the laser 1 intervention and the timing between the CCD image acquisition; the laser 1 is used as an interference light source of the photoelectric detection device, generates short pulse laser in the form of single pulse, and irradiates the line transfer area array CCD 5.

[0060] Attenuator group 2 includes a first attenuator 21 and a second attenuator 22. The first and second attenuators comprise multiple absorptive neutral density filters with fixed optical density, used to attenuate and adjust laser energy. To prevent multiple reflections of the laser between the neutral density filters, the first attenuator 21 and the second attenuator 22 are alternately placed at angles of 0 to 45° with the optical path. When the laser passes through the filters in the attenuator, the laser energy is absorbed by the filters, and the remaining laser energy continues to propagate through the filters. However, a small portion of the laser energy is reflected by the filters. If the incident planes of the first attenuator 21 and the second attenuator 22 are placed at 90° to the optical path, the reflected laser will be reflected between the multiple filters in the attenuator and eventually enter the CCD, affecting CCD imaging. By alternately placing the first attenuator 21 and the second attenuator 22 at angles of 0 to 45° with the optical path, the reflected laser will be guided outside the optical path, avoiding any impact on CCD imaging.

[0061] When the delay controller 7 sends a TTL level signal to the laser 1, the laser can typically be externally controlled via the TTL level signal. The laser 1 emits a single-pulse laser. The laser energy is first attenuated by the attenuator assembly 2 to prevent excessive laser energy from damaging the CCD. Since the minimum laser energy of pulsed lasers commonly used in industry or laboratories is still much higher than the damage threshold of the CCD, the transmittance, number, and different combinations of attenuators need to be determined based on the actual output energy of the laser. The transmittance of commonly used neutral density filters provided by optical component manufacturers is generally 79%, 63%, 50%, 40%, 32%, 25%, 10%, 5%, 1%, 0.1%, and 0.01%.

[0062] The laser beam is then split in two by beam splitter 3. The first beam irradiates probe 8 for laser energy monitoring, while the second beam irradiates the CCD chip surface via focusing lens 4. If the feedback value obtained from the laser energy monitoring does not meet expectations, the transmittance and number of attenuators are adjusted until the laser energy measured by probe 8 meets expectations. At this point, if delay controller 7 sends a TTL level signal to the CCD to control when the CCD starts working, the CCD will acquire the laser interference image and record it on a computer. The acquired output image, or laser interference image, is then processed to extract the crosstalk lines and laser spot positions, verifying whether the control of carrier transport has achieved the expected results.

[0063] like Figure 2 The working principle of a line-by-line transfer-type area CCD is shown in the figure. During CCD operation, the CCD image acquisition process mainly includes:

[0064] Step S201: photoelectric conversion and charge storage;

[0065] When the laser irradiates the photosensitive region of the pixel, according to the size of the light power, the potential well will obtain different concentrations of carrier charges and store them.

[0066] Step S202: vertical transfer of signal charges;

[0067] At the readout transfer moment, the signal charges are read out to the potential well of the vertical transfer channel and are sequentially transported downstream to the horizontal transfer channel under the driving of the vertical clock signal.

[0068] Step S203: horizontal transfer of signal charges;

[0069] Under the driving of the horizontal clock signal, the signal charges are horizontally transported to the readout amplifier.

[0070] Step S204: output detection of signal charges;

[0071] The signal is read out from the readout amplifier, and the signal readout detection is completed.

[0072] As shown in Figure 3 , a timing diagram of short pulse laser single pulse loading in the single frame mode of the CCD is given.

[0073] Figure 3 In (a), the CCD starts integration from 0 ms, and then the short pulse laser irradiates the CCD after the CCD starts working with a delay of Δt.

[0074] Figure 3 The signal in (b) represents the readout transfer action, which occurs at the readout transfer moment (t=T e =T readout) after the CCD starts working. The variable of the time axis is t=T readout, and the signal charges generated and collected by each photosensitive unit will be synchronously transported to the corresponding transfer potential well through the readout transfer action. In the single frame mode, the CCD only performs readout transfer once in the image acquisition period.

[0075] Figure 3 The single signal shown in (c) represents a vertical transfer action, which transports the signal charges to the downstream pixel by one row. The vertical transfer potential well queue maintains uniform directional motion in the image acquisition period.

[0076] As shown in Figure 4 , a schematic diagram of the transport control method of the carrier induced by pulsed laser irradiation is given. The method comprises the following steps:

[0077] Step S401, setting the integration time T of the CCD e and calculating the transfer speed v of the vertical transfer potential well of the CCD:

[0078]

[0079] In the formula, L is the number of effective pixels of the CCD in the vertical direction.

[0080] Step S402: Obtain the minimum delay time Δt required for the crosstalk line image to appear. start and maximum delay time Δt end :

[0081]

[0082] Δtend=Tread out +Δtstart (3)

[0083] Depend on Figure 3 As shown in the step-by-step transfer type area array CCD working timing process, the integration end time T e With CCD readout transfer time T readout Overlap, i.e., T readout =T e When Δt is at Δt start and Δt end Between (Δt) start <Δt<Δt end In the output image of the CCD, crosstalk lines can be observed. Since the laser energy is mainly concentrated on a small number of pixels in the center of the laser spot, the longitudinal extension of the crosstalk lines passes through the center of the laser spot. That is, the x-coordinate of the crosstalk line center on the CCD is the same as the x-coordinate of the center pixel of the laser irradiated area on the CCD. spot Maintain consistency;

[0084] Step S403: Set the irradiation position (x) of the laser on the surface of the CCD chip. spot y spot ), where x spot and y spot These represent the pixel positions of the laser spot center at the laser irradiation location in the horizontal and vertical directions of the CCD, respectively.

[0085] Step S404: Calculate the delay time Δt and the spatial location (x) of the center pixel of the crosstalk short line based on the expected spatial distribution of the crosstalk lines. crosstalk y crosstalk It can be expressed by the following formula:

[0086] x crosstalk =x spot (4)

[0087] y crosstalk =L-(Δt-Δt) start )×v, Δt start ≤Δt≤Δtend (5)

[0088] According to the formula (1) ~ (5) can determine the required delay time Δt; when the position of the crosstalk line expected distribution is determined, that is, the value of y crosstalk , L is the effective pixel number of the CCD in the longitudinal direction, L is a known quantity, Δt start is determined by formula (2), v is determined by formula (1), and finally the value of Δt can be calculated.

[0089] Step S405, determine whether the control CCD expected output image includes the laser main spot:

[0090] If the laser main spot and the crosstalk line are included, the delay time Δt is controlled to be: the minimum delay time Δt start <Δt< integral time T e ;

[0091] If only the crosstalk line is included without the laser main spot, the delay time Δt is controlled to be: integral time T e <Δt< maximum delay time Δt end ;

[0092] If only the laser main spot is included, the delay time Δt is controlled to be: 0 < Δt < minimum delay time Δt start ;

[0093] If there is no laser main spot and no crosstalk line, the delay time Δt is controlled to be: maximum delay time Δt end <Δt<2*T e ;

[0094] Step S406, after determining the required delay time Δt, the delay time controller is used to set the delay time between the laser intervention time and the CCD acquisition pattern to the required delay time Δt.

[0095] The delay time controller sends a TTL signal to trigger the laser and the CCD, the laser sends pulsed laser, the laser passes through the attenuation piece combination, the beam splitter, the focusing lens, and irradiates on the CCD chip, the probe and the energy meter record the laser energy at the same time, and finally the image of the crosstalk phenomenon generated by the pulsed laser irradiating the CCD is obtained. According to the light energy of the used laser and the expected laser energy reaching the CCD, the transmittance of the attenuation piece and the number of attenuation pieces are determined, and the energy after attenuation is verified by the probe until the appropriate attenuation piece combination is selected.

[0096] Example 1: generate a CCD image including a laser main spot and a crosstalk line.

[0097] The laser parameters are set so that the laser energy reaching the CCD surface is 15 nJ; the CCD integration time is set to Te = Treadout = 33 ms; the integration time Te also represents the exposure time, so e is used as the subscript; Treadout is the readout transfer time, indicating the moment when the readout transfer action is performed. The center pixel coordinates of the laser spot irradiated area are set to (705, 540).

[0098] Figure 3 The acquisition cycle shown is only one cycle. Since a single-frame mode is used, only one cycle needs to be considered. The time of one cycle is approximately 2*Te. The integration or exposure is performed during the first Te time period, and the signal charge is transmitted during the second Te time period. Figure 3 The three time axes shown in sub-figures (a), (b), and (c) represent the internal actions of the CCD camera. The readout transfer and vertical transfer are both charge transfer actions performed by the CCD camera.

[0099] Because y spot =540, L=1040, T e =T readout =33ms, the minimum delay Δt for crosstalk is calculated according to formulas (2) and (3). start =17ms and maximum delay Δt end =50ms;

[0100] Assuming the expected CCD output image contains the main laser spot and crosstalk lines, according to Figure 4 As shown in the flowchart, Δt needs to be controlled within Δt. start =17ms to T e = Between 33ms; assuming the expected crosstalk short lines are distributed at positions (x... crosstalk y crosstalk = (705, 761), and the delay time Δt calculated according to formulas (4) and (5) should be set to 26ms.

[0101] After determining the required delay time Δt = 26 ms, the delay time Δt between the CCD and the pulsed laser was set to 26 ms using a delay controller. The output image was obtained after irradiating the row-by-row transfer-type area array CCD with a nanosecond pulsed laser at a laser energy of 15 nJ. The obtained CCD output image is shown below. Figure 5 As shown, the image displays a circular main laser spot and linear crosstalk lines. The coordinates of the center of the laser spot image are = (x... spot y spot ) = (705, 540), the coordinates of the crosstalk line image are (x crosstalk y crosstalk= (705, 761). The experimental results further verify the reliability of the carrier transport control method for pulsed laser irradiation photodetector proposed in this invention, which can accurately control the image content and the imaging position of crosstalk lines in the image.

[0102] Example 2: Generate a CCD image that includes only the main laser spot.

[0103] Set the laser parameters so that the laser energy reaching the CCD surface is 15nJ; set the CCD integration time Te = Treadout = 33ms; set the center pixel coordinates of the laser spot irradiation area to (705, 540).

[0104] Because y spot =540, L=1040, T e =T readout =33ms, the minimum delay Δt for crosstalk is calculated according to formulas (2) and (3). start =17ms and maximum delay Δt end =50ms;

[0105] Assuming the expected CCD output image includes only the main laser spot, according to Figure 4 As shown in the flowchart, Δt needs to be controlled between 0ms and Δt. start The value should be between 17ms and 10ms. In this embodiment, Δt is selected as 10ms.

[0106] After determining the required delay time Δt = 10 ms, the delay time Δt between the CCD and the pulsed laser was set to 10 ms using a delay controller. The output image was obtained after irradiating the row-by-row transfer array CCD with a nanosecond pulsed laser at a laser energy of 15 nJ. The obtained CCD output image is shown below. Figure 6 As shown, the image shows a circular laser main spot imaging.

[0107] Example 3: Generate a CCD image that includes only crosstalk lines.

[0108] Set the laser parameters so that the laser energy reaching the CCD surface is 15nJ; set the CCD integration time Te = Treadout = 33ms; set the center pixel coordinates of the laser spot irradiation area to (705, 540).

[0109] Because y spot =540, L=1040, T e =T readout =33ms, the minimum delay Δt for crosstalk is calculated according to formulas (2) and (3). start =17ms and maximum delay Δt end= 50 ms;

[0110] Assuming that the expected CCD output image contains only crosstalk lines, according to Figure 4 From the flow chart, it is known that the delay time Δt needs to be controlled between Δt e = 33 ms and Δt end = 50 ms; assuming that the expected crosstalk short line in the CCD output image is located at (x crosstalk , y crosstalk ) = (705, 162), according to formulas (4) and (5), the delay time Δt should be set to 45 ms.

[0111] After determining the required delay time Δt = 45 ms, the delay controller is set to 45 ms between the CCD and the pulsed laser, and the output image obtained after the nanosecond pulsed laser irradiates the line-by-line transfer type area array CCD with a laser energy of 15 nJ. The obtained CCD output image is shown in Figure 7 , and linear crosstalk lines can be seen in the image.

[0112] Example 4: Generate a CCD image without a laser main spot and crosstalk lines.

[0113] The laser parameters are set so that the laser energy of the outgoing laser reaching the CCD surface is 15 nJ; the integration time Te of the CCD is set to Treadout = 33 ms; and the center pixel coordinates of the laser spot irradiation site are set to (705, 540);

[0114] Since y spot = 540, L = 1040, T e = T readout = 33 ms, according to formulas (2) and (3), the minimum delay time Δt start = 17 ms and the maximum delay time Δt end = 50 ms appear crosstalk lines;

[0115] Assuming that the expected CCD output image contains only crosstalk lines, according to Figure 4 From the flow chart, it is known that the delay time Δt needs to be controlled between Δt end = 50 ms and 2*T e = 66 ms, and the delay time Δt is set to 55 ms in this embodiment.

[0116] After determining the required delay time Δt = 55 ms, the delay controller is set to 55 ms between the CCD and the pulsed laser, and the output image obtained after the nanosecond pulsed laser irradiates the line-by-line transfer type area array CCD with a laser energy of 15 nJ. There is no laser main spot and crosstalk line in the obtained CCD output image.

[0117] The application can achieve picosecond-level control in the time scale, for example, the delay controller used in the embodiment has a precision of 5 ps, which depends on the control precision of the delay controller; and can achieve pixel-level control in the space scale, and the size of a single pixel in a CCD is about 10 microns, and the size of a single pixel of the CCD used in the embodiment is 6.45 microns.

[0118] The application discloses a device and method for controlling the transport of carriers induced by pulsed laser irradiation, which can control the crosstalk phenomenon of the transport of photo-generated carriers in photoelectric detection devices in the time and space scales, and discloses the formation mechanism of the short-time and short-space distribution phenomenon of the crosstalk of photoelectric detection devices irradiated by short-pulse laser, and realizes the control method of the transport of photo-generated carriers by short-pulse laser. By controlling the time delay between the starting time of the photoelectric detection device and the intervention time of the short-pulse laser, the irradiation position of the laser, and the like, the spatial distribution control of the crosstalk phenomenon of the photoelectric detection device irradiated by the short-pulse laser can be realized.

[0119] In addition, the exemplary embodiments according to the present application can also provide a computer-readable storage medium storing a computer program. The computer-readable storage medium stores a computer program which, when executed by a processor, causes the processor to perform the method for controlling the transport of carriers induced by pulsed laser irradiation according to the exemplary embodiments of the present application. The computer-readable recording medium is any data storage device that can store data read by a computer system. Examples of the computer-readable recording medium include a read-only memory, a random access memory, a read-only optical disc, a magnetic tape, a floppy disc, an optical data storage device, and a carrier such as data transmission through an internet via a wired or wireless transmission path.

[0120] In addition, the exemplary embodiments according to the present application can also provide a computing device. The computing device includes a processor and a memory. The memory is used to store a computer program. The computer program is executed by the processor to cause the processor to perform the method for controlling the transport of carriers induced by pulsed laser irradiation according to the exemplary embodiments of the present application.

[0121] Although the present application is described herein in conjunction with various embodiments, other variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from an inspection of the drawings, the disclosure, and the appended drawings. In the specification, the word "comprising" does not exclude other components or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit can implement several of the functions listed in the specification. Some measures are described in mutually different embodiments, but this does not mean that these measures cannot be combined advantageously.

[0122] Although the present application has been described in connection with the preferred embodiments thereof with reference to the specific content thereof, it will be apparent to those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the application. Accordingly, the description and drawings are to be regarded as illustrative in nature and are not restrictive. It will be apparent that those skilled in the art can modify and adapt the application without departing from the spirit and scope of the application. Accordingly, such modifications and variations are intended to fall within the scope of the application and its equivalents.

Claims

1. A device for controlling the transport of photoinduced carriers by pulsed laser irradiation, characterized in that It comprises: laser (1), attenuation piece group (2), beam splitter (3), focusing lens (4), line-by-line transfer type area array CCD (5), computer (6), delay controller (7), probe (8), energy meter (9); line-by-line transfer type area array CCD (5) is connected with delay controller (7) and computer (6), delay controller (7) is also connected with laser (1), probe (8) is connected with energy meter (9), attenuation piece group (2), beam splitter (3), focusing lens (4) are coaxial in turn on the light path between laser (1) and line-by-line transfer type area array CCD (5); The pulsed laser emitted by the laser is attenuated by the attenuation piece group (2), then divided into two beams of pulsed laser by the beam splitter (3), the first beam of pulsed laser is used to irradiate the probe (8), the second beam of pulsed laser is used to irradiate the line-by-line transfer type area array CCD (5), and the focusing lens (4) is used to focus the second beam of pulsed laser, so that the second beam of pulsed laser reaches the energy density required to produce crosstalk phenomenon on the chip surface of the line-by-line transfer type area array CCD (5); The computer (6) is used for parameter setting of the line-by-line transfer type area array CCD (5), and recording the interference image generated after the pulsed laser irradiates the CCD; the delay controller (7) is used for controlling the timing between the intervention time of the laser (1) and the image acquisition of the line-by-line transfer type area array CCD; the laser (1) is used as the interference light source of the photoelectric detection device, generates pulsed laser in the form of single pulse, and irradiates the line-by-line transfer type area array CCD (5); the probe (8) is used for measuring the energy of the first beam of pulsed laser, and the energy meter (9) is used for displaying the measurement value of the probe (8) to the energy of the first beam of pulsed laser.

2. The pulsed laser irradiation induced carrier transport control device according to claim 1, wherein the number of filters or the transmittance of the attenuation pieces in the attenuation piece group (2) is adjusted according to the measured laser energy value of the energy meter (9) to make the second beam of laser reach the energy density required to produce crosstalk phenomenon on the chip surface of the line-by-line transfer type area array CCD (5) and be lower than the energy density threshold value which can cause damage to the CCD.

3. The pulsed laser irradiation induced carrier transport control device according to claim 1, wherein the attenuation piece group comprises a first attenuation piece (21) and a second attenuation piece (22) arranged in sequence along the light path.

4. The pulsed laser irradiation induced carrier transport control device according to claim 3, wherein the first attenuation piece (21) and the second attenuation piece (22) are alternately placed at an angle of 0-45° with the light path.

5. The pulsed laser irradiation induced carrier transport control device according to claim 3, wherein the pulsed laser is femtosecond pulsed laser, or picosecond pulsed laser, or nanosecond pulsed laser.

6. The pulsed laser irradiation induced carrier transport control device according to claim 1, wherein the delay controller (7) sends a TTL level signal to the laser 1, and the laser emits pulsed laser in the form of single pulse according to the TTL level signal. ​ ​ ​ ​ ​ The delay controller (7) sends a TTL level signal to the line transfer area array CCD, and the line transfer area array CCD determines the starting time according to the TTL level signal, and collects the laser interference image and records it through the computer. 7.The device of claim 1, wherein, The computer is configured to set an integration time of the line transfer area array CCD and a position of the pulsed laser irradiation on the surface, to obtain a transfer speed of a vertical transfer potential well of the line transfer area array CCD according to a number of vertical pixels and the integration time, to obtain a minimum delay time for the crosstalk line by dividing a vertical coordinate of the position of the pulsed laser irradiation by the transfer speed, to obtain a maximum delay time for the crosstalk line by summing the minimum delay time and a readout time of the line transfer area array CCD, and to determine the required delay time Δt according to a spatial position of the expected crosstalk line image. The delay controller is configured to set the delay time Δt between the CCD and the pulsed laser, and to control the pulsed laser to irradiate the line transfer area array CCD according to the delay time. The computer is configured to collect readout data of the line transfer area array CCD, and to obtain the expected output image.

8. A method for controlling the transport of photoinduced carriers based on the pulsed laser irradiation of the device according to claim 1, characterized by that, The method comprises the following steps: setting an integration time of the line transfer area array CCD and a position of the pulsed laser irradiation on the surface, obtaining a transfer speed of a vertical transfer potential well of the line transfer area array CCD according to a number of vertical pixels and the integration time, obtaining a minimum delay time for the crosstalk line by dividing a vertical coordinate of the position of the pulsed laser irradiation by the transfer speed, and obtaining a maximum delay time for the crosstalk line by summing the minimum delay time and a readout time of the line transfer area array CCD, determining the required delay time according to a spatial position of the expected crosstalk line image, controlling the delay controller to set the delay time between the CCD and the pulsed laser, and to control the pulsed laser to irradiate the line transfer area array CCD according to the delay time, and obtaining the expected output image. 9.The method of claim 8, wherein the determining the required delay time according to the spatial position of the expected crosstalk line image comprises: taking a horizontal coordinate of the position of the pulsed laser irradiation as a horizontal coordinate of the crosstalk line, taking a difference between the required delay time and the minimum delay time as a transfer distance by multiplying the difference by the transfer speed, and taking a vertical coordinate of the crosstalk line as a difference between the number of vertical pixels and the transfer distance, and obtaining the required delay time according to the vertical coordinate of the crosstalk line, the minimum delay time, and the transfer speed. 10.The method of claim 9, wherein the determining the required delay time according to the spatial position of the expected crosstalk line image further comprises a step of determining whether the expected output image of the CCD includes a laser main spot. If the expected output image comprises a laser main spot and a cross-talk line, the control delay time At is: minimum delay time At start < At < integration time T e ; If the expected output image does not comprise the laser main spot but only the cross-talk lines, the control delay time At is: integration time T e <At < maximum delay time At end ; If the expected output image comprises only the laser main spot, the control delay time Δt is: 0 < Δt < minimum delay time Δt start ; If the expected output image has neither the laser main spot nor the crosstalk line, the control delay time Δt is: the maximum delay time Δt end <Δt<2*T e .

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