Transportation control device and method for pulse laser irradiation induced carriers

Abstract

The invention discloses a pulse laser irradiation induced carrier transport control device and a pulse laser irradiation induced carrier transport control method. The device comprises a laser (1), an attenuation slice group (2), a beam splitter (3), a focusing lens (4), a line-by-line transfer type area array CCD (charge coupled device) (5), a computer (6) and a delay controller (7), the line-by-line transfer type area array CCD is connected with the delay controller and the computer, the delay controller is further connected with the laser, and the attenuation slice combination, the beam splitter and the focusing lens are sequentially distributed on a light path between the laser 1 and the line-by-line transfer type area array CCD on the same optical axis; the delay controller is used for adjusting an image output result by controlling the delay time between the laser output of the laser and the CCD; the laser serves as an interference light source of the photoelectric detector, generates pulse laser in a monopulse mode, and irradiates the line-by-line transfer type area array CCD. According to the invention, the image position of the crosstalk line in the image of the CCD can be accurately controlled by controlling the delay time.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric detection devices, and in particular to a transport control device and method for pulse laser irradiation-induced carriers. Background Art

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

[0003] As a strong light source, laser technology has attracted great attention for the optical imaging interference caused by CCD irradiation. Laser irradiation on CCD is usually divided into two types: laser interference and laser damage according to the degree of influence. Laser interference mainly refers to temporary interference phenomena such as saturation, crosstalk, and oversaturation after laser irradiation on CCD. When the CCD camera takes pictures, the laser is irradiated into the CCD camera. The output image will contain some interference phenomena such as saturation, crosstalk, and oversaturation due to the laser irradiation, which will temporarily reduce the performance of the photodetector. When the laser irradiation stops, the impact will gradually subside. Laser damage mainly refers to the permanent damage to the CCD image sensor such as deformation, ablation, and perforation caused by laser irradiation on CCD. When the laser irradiation stops, the impact cannot be restored.

[0004] When laser irradiation interferes with and damages CCD, it will affect CCD imaging to varying degrees. Usually, the laser irradiation conditions required for laser interference are easier to achieve. Laser irradiation conditions mainly refer to laser energy density, which is laser energy / laser spot area on the CCD surface. As the laser energy density increases from small to large, laser interference occurs first, followed by laser damage. Therefore, the interference effect of laser irradiation on CCD has also received more attention.

[0005] Based on the existing research, there are still several new problems that have not been solved in the study of laser irradiation CCD interference effect:

[0006] 1) Since the peak power of pulsed laser is usually high, the existing research focuses on damage, while ignoring the research on laser interference effect. No further research has been conducted on the interference effect caused by pulsed laser irradiation on CCD.

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

[0008] 3) Lack of control over the transport of photogenerated carriers controlled by pulsed lasers. Due to the transient effect of pulsed lasers, the generated photogenerated carriers will affect the imaging on a spatial scale as they are physically transported during the imaging process, but a method for controlling the transport of photogenerated carriers by pulsed lasers has not yet been proposed. Summary of the invention

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

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] According to one aspect of the present invention, there is provided a transport control device for pulsed laser irradiation-induced carriers, comprising:

[0012] Laser 1, attenuation plate group 2, beam splitter 3, focusing lens 4, line-by-line transfer type CCD array 5, computer 6, delay controller 7, probe 8, energy meter 9; the line-by-line transfer type CCD array 5 is connected to the delay controller 7 and the computer 6, the delay controller 7 is also connected to the laser 1, the probe 8 is connected to the energy meter 9, the attenuation plate group 2, the beam splitter 3, and the focusing lens 4 are distributed in sequence on the same optical axis on the optical path between the laser 1 and the line-by-line transfer type CCD array 5;

[0013] The pulse laser emitted by the laser is attenuated by the attenuation plate group 2 and then divided into two pulse laser beams by the beam splitter 3. The first pulse laser beam is used to irradiate the probe 8, and the second pulse laser beam is used to irradiate the line-by-line transfer type area array CCD5. The focusing lens 4 is used to focus the second pulse laser beam, so that the second pulse laser beam reaches the energy density required to generate the crosstalk phenomenon on the chip surface of the line-by-line transfer type area array CCD5.

[0014] The computer 6 is used to set parameters for the line-by-line transfer type area array CCD5, and to record the interference image generated after the pulse laser irradiates the CCD; the delay controller 7 is used to control the timing between the intervention of the laser 1 and the CCD image acquisition; the laser 1 serves as an interference light source for the photoelectric detection device, generates a pulsed laser in the form of a single pulse, and irradiates the line-by-line transfer type area array CCD5; the probe 8 is used to measure the energy of the first beam of pulsed laser, and the energy meter 9 is used to display the measurement value of the probe 8 on the energy of the first beam of pulsed laser.

[0015] According to one embodiment of the present invention, the number of filters or the transmittance of the attenuation plate in the attenuation plate combination 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 to produce the crosstalk phenomenon on the chip surface of the line-by-line transfer type area array CCD5 and is lower than the energy density threshold that causes damage to the CCD.

[0016] According to an embodiment of the present invention, the attenuation plate group includes a first attenuation plate 21 and a second attenuation plate 22 arranged sequentially along the optical path.

[0017] According to an embodiment of the present invention, the first attenuation plates 21 and the second attenuation plates 22 are alternately placed at an angle of 0 to 45 degrees with the optical path.

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

[0019] According to one embodiment of the present invention, the delay controller 7 sends a TTL level signal to the laser 1, and the laser sends a single-pulse pulse laser according to the TTL level signal; the delay controller 7 sends a TTL level signal to the line-by-line transfer type area array CCD, and the line-by-line transfer type area array CCD determines the starting working time according to the TTL level signal, and collects the laser interference image and records it through a computer.

[0020] According to one embodiment of the present invention, the computer is used to set the integration time of the progressive transfer type area array CCD and the pulse laser irradiation position of the surface; obtain the transmission speed of the vertical transmission potential well of the progressive transfer type area array CCD according to the vertical pixel number and the integration time; use the quotient of the ordinate of the pulse laser irradiation position and the transmission speed as the minimum delay time for the occurrence of crosstalk lines, and use the sum of the minimum delay time and the readout time of the progressive transfer type area array CCD as the maximum delay time for the occurrence of crosstalk lines; determine the required delay time Δt according to the expected spatial position of the crosstalk line image;

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

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

[0023] Set the integration time of the progressive transfer type area array CCD and the pulsed laser irradiation position on the surface;

[0024] According to the number of vertical pixels and the integration time, the transmission speed of the vertical transmission potential well of the progressive transfer type area array CCD is obtained;

[0025] The quotient of the ordinate of the pulse laser irradiation position and the transmission speed is taken as the minimum delay time for the occurrence of crosstalk lines, and the sum of the minimum delay time and the readout time of the line-by-line transfer type area array CCD is taken as the maximum delay time for the occurrence of crosstalk lines;

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

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

[0028] The step of determining the required delay time according to the expected spatial position of the crosstalk line image comprises:

[0029] The horizontal coordinate of the pulse laser irradiation position is used as the horizontal coordinate of the crosstalk line; the difference obtained by subtracting the minimum delay time from the required delay time and multiplying it by the transmission speed is defined as the transmission distance; the vertical coordinate of the crosstalk line is defined as the difference between the number of vertical pixels and the transmission distance; the required delay time is obtained based on the set vertical coordinate of the crosstalk line and the calculated minimum delay time and transmission speed.

[0030] The method of determining the required delay time according to the expected spatial position of the crosstalk line image also includes the step of determining whether the output image expected by the control CCD includes the laser main spot:

[0031] If the expected output image includes the laser main spot and the crosstalk line, the control delay time Δt is: 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 control delay time Δt is: the integration time T e <Δt<Maximum delay time Δt end ;

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

[0034] If the expected output image has no laser main spot and no crosstalk line, the control delay time Δt is: Maximum delay time Δt end <Δt<2*T e .

[0035] The invention discloses a pulse laser irradiation induced carrier transport control device and method, realizes the control of photogenerated carrier transport on the crosstalk phenomenon of photodetection devices in both time and space scales, reveals the formation mechanism of the short-line spatiotemporal distribution phenomenon of crosstalk of photodetection devices irradiated by short-pulse laser, and realizes the short-pulse laser control method of photogenerated carrier transport control. Compared with the prior art, the invention has the following beneficial effects:

[0036] 1. By controlling the time delay between the start of the CCD device and the short-pulse laser intervention, the laser irradiation position, etc., the spatial distribution control of the crosstalk phenomenon generated by the short-pulse laser irradiation photoelectric detection device is achieved;

[0037] 2. It can achieve picosecond control on the time scale, and the delay controller accuracy is 5ps, which depends on the control accuracy of the delay controller;

[0038] 3. Pixel-level control can be achieved on a spatial scale. Usually, 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.

[0039] 4. Based on the formation mechanism of the spatiotemporal distribution phenomenon of short-line crosstalk in photodetector devices irradiated by short-pulse laser, the short-pulse laser can be precisely controlled to control the transport of photogenerated carriers. Based on time delay control and pixel position control, laser spot images and / or crosstalk line images can be generated at specified pixel coordinate positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0041] Figure 1 Schematic diagram of a transport control device for carriers induced by pulse laser irradiation according to an exemplary embodiment of the present invention.

[0042] Figure 2 4 is a working principle diagram of a line-by-line transfer type area array CCD according to an exemplary embodiment of the present invention.

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

[0044] Figure 4 Schematic diagram of a method for controlling carrier transport induced by pulsed laser irradiation according to an exemplary embodiment of the present invention.

[0045] Figure 5FIG. 4 is a schematic diagram of a CCD image including a laser spot and a crosstalk line according to an exemplary embodiment of the present invention.

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

[0047] Figure 7 is a schematic diagram of a CCD image including only crosstalk lines according to an exemplary embodiment of the present invention.

[0048] Reference numerals:

[0049] 1-laser; 2-attenuation plate group; 3-beam splitter; 4-focusing lens; 5-line-by-line transfer type CCD array; 6-computer; 7-delay controller; 8-probe; 9-energy meter; 21-first attenuation plate; 22-second attenuation plate. DETAILED DESCRIPTION

[0050] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0051] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0052] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The following at least one item (items) or similar expressions thereof refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (items) of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

[0055] Laser 1, attenuation sheet group 2, beam splitter 3, focusing lens 4, line-by-line transfer type CCD array 5, computer 6, delay controller 7, probe 8, energy meter 9. Attenuation sheet group 2 includes a first attenuation sheet 21 and a second attenuation sheet 22.

[0056] The line-by-line transfer type CCD array 5 is connected to the delay controller 7 and the computer 6. The delay controller 7 is also connected to the laser 1. The probe 8 is connected to the energy meter 9. The attenuation plate assembly 2, the beam splitter 3, and the focusing lens 4 are sequentially distributed on the optical path between the laser 1 and the line-by-line transfer type CCD array 5. The attenuation plate assembly 2 is located after the laser 1, the beam splitter 3 is located after the attenuation plate assembly 2, and the focusing lens 4 is located after the beam splitter 3. The attenuation plate assembly 2, the beam splitter 2, the focusing lens 4 and the laser 1 share the same optical axis, and the probe 8 is also located after the beam splitter 3.

[0057] The beam splitter 3 is used to split the laser light emitted by the laser into two beams of laser light, so as to realize the beam splitting of the laser light: the first beam is used to irradiate the probe, and the second beam is used to irradiate the line-by-line transfer type CCD array 5. The focusing lens 4 is used to focus the laser light so that the laser light reaches the energy density required to produce the crosstalk phenomenon on the chip surface of the line-by-line transfer type CCD array 5. The probe 8 is used to measure the energy of the first laser beam, and adjust the attenuation plate combination 2 according to the measured laser energy value, so as to increase or decrease the number of attenuation plates or the transmittance. The energy meter 9 is used to display the measurement value of the probe 8 on the energy of the first laser beam.

[0058] When the outgoing laser of the laser 1 irradiates the line-by-line transfer type area array CCD 5, the photosensitive area in the pixel of the line-by-line transfer type area array CCD 5 will undergo photoelectric conversion and generate signal charges, which are transported in the transmission channel of the line-by-line transfer type area array CCD 5. Finally, the signal charges are identified and converted by the readout end of the line-by-line transfer type area array CCD 5 to output the captured image.

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

[0060] The attenuation plate group 2 includes a first attenuation plate 21 and a second attenuation plate 22. The first and second attenuation plates include multiple absorptive neutral density filters with fixed optical density to attenuate and adjust the laser energy. In order to prevent the laser from being reflected multiple times between the neutral density filters, the first attenuation plate 21 and the second attenuation plate 22 are placed alternately at an angle of 0 to 45 degrees with the optical path. When the laser passes through the filter in the attenuation plate, the laser energy will be absorbed by the filter, and the remaining laser energy will continue to transmit through the filter, but a small part of the laser energy will be reflected by the filter. If the incident plane of the first attenuation plate 21 and the second attenuation plate 22 is placed at 90 degrees with the optical path, the reflected laser will be reflected between the multiple filters in the attenuation plate and finally enter the CCD, affecting the imaging of the CCD. The first attenuation plate 21 and the second attenuation plate 22 are placed alternately at an angle of 0 to 45 degrees with the optical path, and the reflected laser will be guided outside the optical path, avoiding the influence on the CCD imaging.

[0061] When the delay controller 7 sends a TTL level signal to the laser 1, the laser can usually be externally controlled by the TTL level signal. The laser 1 emits a single pulse of pulsed laser, which first passes through the attenuation plate combination 2 to attenuate the laser energy to prevent the laser energy from being too high and causing damage to the CCD. Since the minimum laser energy of pulsed lasers commonly used in industry or laboratories is still far greater than the damage threshold of the CCD, the transmittance, quantity and different combinations of the attenuation plates need to be determined based on the actual light 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 then passes through the beam splitter 3, splitting the laser beam into two, of which the first beam is irradiated onto the probe 8 to monitor the laser energy, and the second laser beam is irradiated onto the chip surface of the CCD through the focusing lens 4. If the feedback value obtained from the monitoring of the laser energy does not meet expectations, adjust the transmittance and number of the attenuation plates until the laser energy measured by the probe 8 meets expectations. At this time, if the delay controller 7 sends a TTL level signal to the CCD to control when the CCD starts working, the signal starts the CCD to start working, and the CCD will collect the laser interference image and record it through a computer. The collected output image, or the so-called laser interference image, is processed, and the positions of the crosstalk lines and laser spots in the image are extracted to verify whether the control of carrier transport has achieved the expected results.

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

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

[0065] When laser light is irradiated to the photosensitive area of ​​the pixel, the collecting potential well will obtain and store carrier charges of different concentrations depending on the light power.

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

[0067] At the readout transfer moment, the signal charge is read out into the potential well of the vertical transmission channel and is sequentially transported downward to the horizontal transmission channel under the drive of the vertical clock signal.

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

[0069] Driven by the horizontal clock signal, the signal charge is horizontally transferred to the readout amplifier.

[0070] Step S204: signal charge output detection;

[0071] The signal is read out from the sense amplifier to complete the signal readout detection.

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

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

[0074] Figure 3 The signal in (b) represents the readout transfer action, which occurs at the readout transfer time (t = Te = Treadout) after the CCD starts working. The variable on the time axis is t = Treadout, and the signal charge generated and collected by each photosensitive unit will be synchronously transferred to the corresponding transfer potential well through the readout transfer action. In single-frame mode, the CCD performs only one readout transfer during the image acquisition cycle.

[0075] Figure 3 The single signal shown in (c) represents a vertical transfer action that transfers the signal charge to a row of downstream pixels. The vertical transfer potential well array maintains a uniform and directional motion during the image acquisition cycle.

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

[0077] Step S401: Set the CCD integration time T e , and calculate the transmission velocity v of the vertical transmission potential well of the CCD:

[0078]

[0079] Where L is the effective number of 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 the maximum delay time Δt end :

[0081]

[0082] Δtend=Tread out +Δtstart (3)

[0083] Depend on Figure 3 The working sequence of the line-by-line transfer type CCD shown in the figure shows that the integration ends at the time T e and CCD readout transfer time T readout Coincidence, that is, T readout =T e , when Δt is at Δt start and Δt end Between (Δt start <Δt<Δt end ), crosstalk lines can be observed in the output image of the CCD. Since the laser energy is mainly concentrated on the fewer pixels in the center of the laser spot, the longitudinal extension of the crosstalk line passes through the center of the laser spot, that is, the horizontal coordinate of the center of the crosstalk line on the CCD is the same as the horizontal position x of the central pixel of the laser irradiation part on the CCD. spot Stay consistent;

[0084] Step S403: Set the laser irradiation position (x spot ,y spot ), where x spot and spot are the pixel positions of the center of the laser spot at the laser irradiation position in the horizontal and vertical directions of the CCD, respectively;

[0085] Step S404: Calculate the delay time Δt and the spatial position (x crosstalk ,y crosstalk ) 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] The required delay time Δt can be determined according to formulas (1) to (5); when the expected distribution position of the crosstalk line is determined, y is determined. crosstalk The value of L is the effective number of pixels of the CCD in the vertical direction. L is a known quantity. Δt start 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 output image expected by the control CCD includes the laser main spot:

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

[0091] If the laser main spot is not included but only the crosstalk line is included, the control delay time Δt is: the integration time T e <Δt<Maximum delay time Δt end ;

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

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

[0094] Step S406: After determining the required delay time Δt, use the delay controller to set the delay time between the laser intervention timing and the CCD image acquisition timing to the required delay time Δt.

[0095] The delay controller sends a TTL signal to trigger the laser and CCD. The laser emits a pulsed laser, which is irradiated onto the CCD chip through the attenuation plate combination, beam splitter, and focusing lens. The probe and energy meter simultaneously record the laser energy, and finally obtain an image of the crosstalk phenomenon caused by the pulsed laser irradiating the CCD. According to the light output energy of the laser used and the expected laser energy reaching the CCD, the transmittance and number of attenuation plates are determined, and the attenuated energy is verified through the probe until the appropriate attenuation plate combination is selected.

[0096] Embodiment 1: Generate a CCD image including a laser main spot and crosstalk lines.

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

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

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

[0100] Assuming that the expected CCD output image contains the laser main spot and crosstalk lines, according to Figure 4 As can be seen from the flow chart, it is necessary to control Δt within Δt start =17ms to T e =33ms; Assuming that the expected distribution position of the crosstalk short line in the CCD output image is (x crosstalk ,y crosstalk )=(705,761), according to formulas (4) and (5), it is calculated that the delay time Δt should be set to 26ms.

[0101] After determining the required delay time Δt=26ms, the delay time Δt between the CCD and the pulse laser is set to 26ms through the delay controller, and the output image is obtained after the nanosecond pulse laser irradiates the line-by-line transfer type area array CCD with 15nJ laser energy. The obtained CCD output image is as follows Figure 5 As shown in the figure, the circular main laser spot imaging and the linear crosstalk line imaging can be seen in the image. 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 a pulsed laser irradiated photodetector device proposed in the present invention, which can accurately control the image content and the imaging position of the crosstalk line in the image.

[0102] Embodiment 2: Generate a CCD image including 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 of y spot =540, L=1040, T e =T readout =33ms, according to formula (2) and (3), the minimum delay Δt of the crosstalk line is calculated start =17ms and maximum delay Δt end =50ms;

[0105] Assuming that the expected CCD output image only includes the laser main spot, according to Figure 4 As can be seen from the flow chart, it is necessary to control Δt between 0ms and Δt start =17ms, and in this embodiment, Δt is selected as 10ms.

[0106] After determining the required delay time Δt=10ms, the delay time Δt between the CCD and the pulse laser is set to 10ms through the delay controller, and the output image is obtained after the nanosecond pulse laser irradiates the line-by-line transfer type area array CCD with 15nJ laser energy. The obtained CCD output image is as follows Figure 6 As shown, a circular laser main spot imaging can be seen in the image.

[0107] Example 3: Generate a CCD image including 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 of y spot =540, L=1040, T e =T readout =33ms, according to formula (2) and (3), the minimum delay Δt of the crosstalk line is calculated start =17ms and maximum delay Δt end=50ms;

[0110] Assuming that the expected CCD output image contains only crosstalk lines, according to Figure 4 As can be seen from the flow chart, it is necessary to control Δt within T e =33ms to Δt end =50ms; Assume that the expected crosstalk short line distribution position in the CCD output image is (x crosstalk ,y crosstalk )=(705, 162), according to formulas (4) and (5), it is calculated that the delay time Δt should be set to 45ms.

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

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

[0113] 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);

[0114] Because of y spot =540, L=1040, T e =T readout =33ms, according to formula (2) and (3), the minimum delay Δt of the crosstalk line is calculated start =17ms and maximum delay Δt end =50ms;

[0115] Assuming that there is no laser main spot and crosstalk line in the expected CCD output image, according to Figure 4 As can be seen from the flow chart, it is necessary to control Δt within Δt end =50ms to 2*T e =66ms, in this embodiment, the delay time Δt is set to 55ms.

[0116] After determining the required delay time Δt=55ms, the delay time Δt between the CCD and the pulse laser is set to 55ms by the delay controller, and the output image is obtained after the nanosecond pulse laser irradiates the line-by-line transfer type area array CCD with 15nJ laser energy. The obtained CCD output image does not have the laser main spot and crosstalk line.

[0117] The application of the present invention can achieve picosecond control on the time scale. For example, the delay controller used in the embodiment has an accuracy of 5ps, which depends on the control accuracy of the delay controller. Pixel-level control can be achieved on the spatial scale. Usually, 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 invention discloses a pulse laser irradiation induced carrier transport control device and method, which realizes the control of photogenerated carrier transport on the crosstalk phenomenon of photodetection devices in both time and space scales, reveals the formation mechanism of the short-line spatiotemporal distribution phenomenon of crosstalk of photodetection devices irradiated by short-pulse lasers, and realizes the short-pulse laser controlled photogenerated carrier transport control method. By controlling the time delay between the start of the photodetection device and the short-pulse laser intervention, the laser irradiation position, etc., the spatial distribution control of the crosstalk phenomenon of the photodetection device irradiated by the short-pulse laser is realized.

[0119] In addition, according to an exemplary embodiment of the present invention, a computer-readable storage medium storing a computer program may also be provided. The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform a method for controlling the transport of carriers induced by pulsed laser irradiation according to an exemplary embodiment of the present invention. The computer-readable recording medium is any data storage device that can store data read out by a computer system. Examples of computer-readable recording media include: read-only memory, random access memory, read-only optical disk, magnetic tape, floppy disk, optical data storage device, and carrier wave (such as data transmission through the Internet via a wired or wireless transmission path).

[0120] In addition, a computing device may be provided according to an exemplary embodiment of the present invention. 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 so that the processor executes the computer program of the transport control method of pulsed laser irradiation induced carriers according to an exemplary embodiment of the present invention.

[0121] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0122] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. A pulse laser irradiation induced carrier transport control device, characterized in that: include: A laser (1), an attenuation plate group (2), a beam splitter (3), a focusing lens (4), a line-by-line transfer type CCD array (5), a computer (6), a time delay controller (7), a probe (8), and an energy meter (9); the line-by-line transfer type CCD array (5) is connected to the time delay controller (7) and the computer (6), the time delay controller (7) is also connected to the laser (1), the probe (8) is connected to the energy meter (9), and the attenuation plate group (2), the beam splitter (3), and the focusing lens (4) are coaxially distributed in sequence on the optical path between the laser (1) and the line-by-line transfer type CCD array (5); After being attenuated by an attenuation sheet group (2), the pulse laser emitted by the laser is split into two pulse laser beams by a beam splitter (3), the first pulse laser beam is used to irradiate a probe (8), and the second pulse laser beam is used to irradiate a line-by-line transfer type CCD array (5), and the focusing lens (4) is used to focus the second pulse laser beam, so that the second pulse laser beam reaches the energy density required for generating a crosstalk phenomenon on the chip surface of the line-by-line transfer type CCD array (5); The computer (6) is used to set parameters of a progressive transfer type CCD array (5) and record interference images generated after the pulse laser irradiates the CCD; the delay controller (7) is used to control the timing between the intervention of the laser (1) and the image acquisition of the progressive transfer type CCD array; the laser (1) is used as an interference light source of the photoelectric detection device to generate pulsed laser in a single pulse form to irradiate the progressive transfer type CCD array (5); the probe (8) is used to measure the energy of the first beam of pulsed laser, and the energy meter (9) is used to display the measurement value of the probe (8) on the energy of the first beam of pulsed laser.

2. The pulse laser irradiation induced carrier transport control device according to claim 1, characterized in that: The number of filters or transmittance of the attenuation plates in the attenuation plate assembly (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 to generate the crosstalk phenomenon on the chip surface of the line-by-line transfer type area array CCD (5) and is lower than the energy density threshold that causes damage to the CCD.

3. The pulse laser irradiation induced carrier transport control device according to claim 1, characterized in that: The attenuation plate group comprises a first attenuation plate (21) and a second attenuation plate (22) which are sequentially arranged along the optical path.

4. The pulse laser irradiation induced carrier transport control device according to claim 3, characterized in that: The first attenuation plate (21) and the second attenuation plate (22) are alternately placed at an angle of 0 to 45 degrees with the light path.

5. The pulse laser irradiation induced carrier transport control device according to claim 3, characterized in that: The pulse laser is a femtosecond pulse laser, a picosecond pulse laser, or a nanosecond pulse laser.

6. The pulse laser irradiation induced carrier transport control device according to claim 1, characterized in that: The delay controller (7) sends a TTL level signal to the laser 1, and the laser sends a single pulse of pulsed laser according to the TTL level signal; The delay controller (7) sends a TTL level signal to the line-by-line transfer type area array CCD, and the line-by-line transfer type area array CCD determines the start time of work according to the TTL level signal, collects the laser interference image and records it through a computer.

7. The pulse laser irradiation induced carrier transport control device according to claim 1, characterized in that: The computer is used to set the integration time of the progressive transfer type area array CCD and the pulse laser irradiation position on the surface; obtain the transmission speed of the vertical transmission potential well of the progressive transfer type area array CCD according to the vertical pixel number and the integration time; take the quotient of the ordinate of the pulse laser irradiation position and the transmission speed as the minimum delay time for the occurrence of crosstalk lines, and take the sum of the minimum delay time and the readout time of the progressive transfer type area array CCD as the maximum delay time for the occurrence of crosstalk lines; determine the required delay time Δt according to the expected spatial position of the crosstalk line image; The delay controller is used to set the delay time Δt between the CCD and the pulse laser, and control the pulse laser to irradiate the line-by-line transfer type area array CCD according to the delay time; The computer collects the readout data of the line-by-line transfer type area array CCD to obtain the expected output image.

8. A method for controlling the transport of carriers induced by pulsed laser irradiation based on the device of claim 1, characterized in that: The following steps are involved: Set the integration time of the progressive transfer area array CCD and the pulsed laser irradiation position on the surface; According to the number of vertical pixels and the integration time, the transmission speed of the vertical transmission potential well of the progressive transfer type area array CCD is obtained; The quotient of the ordinate of the pulse laser irradiation position and the transmission speed is taken as the minimum delay time for the occurrence of crosstalk lines, and the sum of the minimum delay time and the readout time of the line-by-line transfer type area array CCD is taken as the maximum delay time for the occurrence of crosstalk lines; Determining the required delay time according to the expected spatial position of the crosstalk line image; The delay controller is controlled to set the delay time between the CCD and the pulse laser, and the pulse laser is controlled to irradiate the line-by-line transfer type area array CCD according to the delay time to obtain the expected output image.

9. The method for controlling the transport of carriers induced by pulsed laser irradiation according to claim 8, characterized in that: The step of determining the required delay time according to the expected spatial position of the crosstalk line image comprises: The abscissa of the pulse laser irradiation position is used as the abscissa of the crosstalk line; The difference obtained by subtracting the minimum delay time from the required delay time and multiplying it by the transmission speed is defined as the transmission distance; the vertical coordinate of the crosstalk line is defined as the difference between the number of vertical pixels and the transmission distance; The required delay time is obtained according to the set ordinate of the crosstalk line and the calculated minimum delay time and transmission speed.

10. The method for controlling the transport of carriers induced by pulsed laser irradiation according to claim 9, characterized in that: The method of determining the required delay time according to the expected spatial position of the crosstalk line image also includes the step of determining whether the output image expected by the control CCD includes the laser main spot: If the expected output image includes the laser main spot and the crosstalk line, the control delay time Δt is: the minimum delay time Δt start <Δt<Integral time T e ; If the expected output image does not include the laser main spot but only includes the crosstalk line, the control delay time Δt is: the integration time T e <Δt<Maximum delay time Δt end ; If the expected output image only includes the main laser spot, the control delay time Δt is: 0<Δt<minimum delay time Δt start ; If the expected output image has no laser main spot and no crosstalk line, the control delay time Δt is: Maximum delay time Δt end <Δt<2*T e .

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