KR20140055026A - Apparatus and method for controlling of silicon photomultiplier device output - Google Patents

Abstract

An apparatus for controlling an output gain of a silicon photomultiplier device according to the present invention comprises an analog signal processing unit for converting light incident on a silicon photomultiplier device into an analog voltage signal; a digital signal processing unit for receiving the analog voltage signal from the analog signal processing unit and converting the received analog voltage signal into a digital signal; and a control unit for controlling the digital signal processing unit and the silicon photomultiplier device. The control unit receives the digital signal from the digital signal processing unit, and compares the digital signal with a threshold value. When the digital signal exceeds the threshold value, the control unit adjusts the output gain of the silicon photomultiplier device by decreasing a voltage output from the silicon photomultiplier device.

Description

TECHNICAL FIELD [0001] The present invention relates to an apparatus and a method for controlling an output gain of a silicon optoelectronic device,

The present invention relates to an apparatus and method for controlling an output gain of a silicon optoelectronic device.

Recently, a silicon photomultiplier (SiPM) device has been devised to replace photomultiplier (PMT) in the optical sensor field.

FIG. 1 is a view showing a correlation of an output gain according to an applied voltage in a conventional vacuum tube type photomultiplier tube device.

The conventional vacuum tube type photomultiplier tube device is a device in which a single photoelectron generated from a photo cathode in front of a vacuum tube is passed through a multi-stage intermediate electrode (die node) and finally amplified to a million- Sensor. Vacuum tube photomultiplier devices typically operate at load voltages greater than 1000V and are characterized by large size and heavy weight. Also, the operation in the magnetic field is limited.

In addition, in the case of a conventional vacuum tube photomultiplier tube device, the log (Gain) is linearly proportional to the applied voltage as shown in FIG. That is, the relation between the output gain Gain and the applied voltage V is Gain? Exp (? V) (? Is a positive proportional constant). Therefore, in the case of a vacuum tube type photomultiplier tube device, it is difficult to control the output gain determined by the feedback by varying the voltage (V) compared with the optical device having a linear relationship between the output gain and the applied voltage.

On the other hand, a silicon photomultiplier tube has a principle similar to an avalanche diode in which a very large electric field is formed in a PN junction at a reverse load voltage, and an incident optical signal is converted into a very large electric signal in the process of electron avalanche Lt; / RTI > In addition, the silicon photomultiplier element amplifies the signal to as many as one million electrons per photon. In addition, there are about 1000 small independent diodes in a size of about 1 mm ² , operating in the Geiger mode, and the reaction signals of all the diodes are combined into one sensor output.

In addition, the silicon photomultiplier tube is very small in size compared to conventional photomultiplier tube (PMT), has very low operating voltage (25 ~ 100V), and is not affected by the magnetic field.

Such a silicon photomultiplier device is composed of more than 500 micro-pixels, and one micro-pixel has a size of about 20 μm. Each micro-pixel independently detects and amplifies the photons. When photons are introduced into each micro-pixel and electrons and holes are generated, amplification occurs by the electric field inside the silicon opto-electronic device, and a signal of a predetermined size is generated and output. At this time, the output signal of the silicon photo- Means a signal obtained by adding signals of a micropixel.

On the other hand, when the amount of light incident on the pixel is large, the output of the pixel is saturated. When the output of the pixel is saturated, there is no change in the output even when the amount of incident light increases, so that the increase in the amount of incident light can not be detected in the silicon optoelectronic device.

Therefore, when the pixel output of the silicon optoelectronic multiplier device is saturated as the incident light amount increases under a given applied voltage condition, it is necessary to reduce the applied voltage so that the output is not saturated at a later time.

In this regard, Korean Patent Laid-Open Publication No. 2010-0063479 (entitled "Silicon Photo Multiplier and Method of Manufacturing the Same") has a flat-plate-like structure and is easily manufactured, effectively isolating each micro- And a method of manufacturing the same.

In addition, Korean Patent Application No. 2011-0109230 (entitled "Silicon Photomultiplier with reduced dark current") uses a low-concentration p-conductivity type silicon substrate and forms a PN-junction layer thereon, ) Discloses a silicon photoelectron multiplication tube with reduced dark current that can reduce the ratio of the dark current generated by the substrate and the dark current generated by the strong electric field generated at the interface between the substrate and the epitaxial layer.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems of the prior art, and it is an object of the present invention to provide a silicon opto-electronic device, which, when output gain is saturated by the amount of light incident on a pixel of a silicon opto- It is an object of the present invention to provide an output gain control apparatus for a silicon optoelectronic device that can reduce the voltage and adjust the output so that the output is not saturated.

According to a first aspect of the present invention, there is provided an apparatus for controlling an output gain of a silicon opto-electronic double-dipole tube element, comprising: an analog signal converting an incident light incident on a silicon opto- A digital signal processing unit for receiving the analog voltage signal from the analog signal processing unit and converting the analog voltage signal into a digital signal, and a control unit for controlling the digital signal processing unit and the silicon opto-electronic expansion pipe device, And controls the output gain of the silicon opto-electronic double-dipole tube device by reducing the voltage output from the silicon opto-electronic double-dipole tube device when the digital signal exceeds the threshold value.

A method of controlling an output gain of a silicon optoelectronic multiplier device through an output gain control device of a silicon optoelectronic multiplier device according to a second aspect of the present invention includes the steps of: Converting the converted analog voltage signal into a digital signal, comparing the digital signal with a threshold value, and adjusting an output gain of the silicon opto-electronic double-dipole tube device according to a result of comparison between the digital signal and a threshold value Wherein the step of adjusting the output gain of the silicon opto-electronic enhancer device comprises the step of reducing the voltage output from the silicon optoelectronic thickener device when the digital signal exceeds the threshold, Lt; / RTI >

According to the above-described embodiment of the present invention, since the pixel output of the silicon opto-electronic double-dipole tube device is not saturated even when the incident light quantity is increased, the dynamic range of the output of the silicon- Can be increased more than 5 times.

In addition, the gain change of the silicon photomultiplier tube according to the applied voltage has a linear relationship, and feedback can be performed based on this linear relationship to accurately adjust the desired output gain variation.

FIG. 1 is a view showing a correlation of an output gain according to an applied voltage in a conventional vacuum tube type photomultiplier tube device.
2 is a block diagram illustrating an apparatus for controlling the output gain of a silicon photomultiplier according to an embodiment of the present invention.
3 is a diagram illustrating a method of controlling an output gain of a silicon photomultiplier according to an embodiment of the present invention.
4 is a graph showing a correlation of output gains according to an applied voltage in a silicon photomultiplier according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

FIG. 2 is a diagram illustrating an apparatus 100 for controlling the output gain of a silicon opto-electronic double-dipole tube device according to an embodiment of the present invention.

The output gain control apparatus 100 of the present invention includes a silicon opto-electronic device 110, an analog signal processing unit 120, a digital signal processing unit 130, and a control unit 140.

2 refers to a hardware component such as software or an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and performs predetermined roles .

However, 'components' are not meant to be limited to software or hardware, and each component may be configured to reside on an addressable storage medium and configured to play one or more processors.

Thus, by way of example, an element may comprise components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, Routines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables.

The components and functions provided within those components may be combined into a smaller number of components or further separated into additional components.

The silicon opto-electronic device 100 has a characteristic in which the output gain is proportional to the voltage applied to the device. Further, when the pixel output of the device is saturated as the incident light amount increases at a given applied voltage, the output gain generally also saturates. The silicon photomultiplier 100 is described in detail in the Background section, and a detailed description thereof will be omitted.

The analog signal processing unit 120 converts the incident light incident on the silicon opto-electronic expansion tube device 110 into an analog voltage signal. At this time, the analog signal processing unit 120 may include a charge amplifier, a fast shaping amplifier, a discriminator, and a slow shaping amplifier.

The charge amplifier plays a role of converting the charge signal of the incident light incident from the silicon opto-electronic double-gate device 110 into an analog voltage signal. At this time, it is preferable to set the appropriate bandwidth of the charge amplifier to 200 MHz or more.

The high-speed shaping amplifier plays a role in shaping the amplification and waveform of the signal. At this time, the shaping time of the fast shaping amplifier is preferably set to 50 ns or less.

The discriminator generates the trigger output signal using the output signal of the high-speed shaping amplifier, and the low-speed shaping amplifier is connected to the analog-to-digital converter to amplify the signal before converting the analog signal to the digital signal, . At this time, it is preferable to set the shaping time of the low speed shaping amplifier to 100 to 200 ns.

The digital signal processor 130 receives the converted analog voltage signal from the analog signal processor 120 and converts the analog voltage signal into a digital signal. At this time, the digital signal processor 130 may include an analog-to-digital converter for converting the analog signal voltage received from the analog signal processor 120 into a digital signal, a large-capacity FPGA (Field Programmable Gate Array), and a data storage device.

Further, since the digital signal processing unit 130 includes a change recognition program for changing the incident light amount of the digital signal, the digital signal processing unit 130 can recognize a change in the incident light amount.

The control unit 140 controls the digital signal processing unit 130 and the silicon opto-electronic expansion tube device 110. At this time, the control unit 140 receives the digital signal from the digital signal processing unit 130 and compares the received digital signal with a threshold value, and when the digital signal exceeds the threshold value, the control unit 140 decreases the voltage output from the silicon photomultiplier device, (110).

In addition, the control unit 140 may perform an operation on each pixel of the silicon photomultiplier element 110, an operation on all pixels in the element, and a plurality of frame operations to adjust the output gain of the silicon opto-electronic double dipole element 110 have.

That is, when the output gain of all the pixels of the silicon opto-electronic-signal expander device 140 is saturated, the control unit 140 can adjust the output gain by reducing the voltage of the silicon opto-electronic signal intensifier device.

The controller 140 may include a small-capacity FPGA or a complex programmable logic device (CPLD), and may further include a data storage device, a digital-to-analog converter (DAC) .

In addition, it includes an applied voltage control device and a control logic program of the silicon opto-electronic expansion pipe device 110 using feedback of a digital signal, and further includes a logic program for controlling the entire system and an interface with an external device And < / RTI >

As described above, the output gain control apparatus 100 of the silicon opto-electronic double-throw device according to the present invention increases the effective dynamic range of the output by at least 5 times, since the pixel output of the device is not saturated even when the amount of light incident on the device increases. can do.

In addition, the gain change of the silicon opto-electronic multiplier device according to the voltage output from the silicon opto-electronicsupplier device has a linear relationship, and feedback can be performed based on this linear relationship, so that the desired output gain variation can be precisely controlled.

3 is a flowchart illustrating a method of controlling an output gain of a silicon photomultiplier tube device according to an embodiment of the present invention.

First, the output gain control device 100 of the silicon opto-electronic expansion tube device receives incident light from the silicon opto-electronic expansion pipe device 110, converts the received light into an analog voltage signal (S310), and outputs the converted analog voltage signal as a digital signal (S320).

Next, the converted digital signal is compared with a threshold value (S330), and the output gain of the silicon opto-electronic multiplier element 110 is adjusted based on the comparison result (S340).

Specifically, when the digital signal is compared with the threshold value and the digital signal exceeds the threshold value in accordance with the comparison result, the output voltage of the silicon opto-electronic double dipole device 110 is controlled by reducing the voltage output from the silicon opto- .

At this time, when the output gain is adjusted by performing the arithmetic function, the output gain can be adjusted by performing the arithmetic operation on the unit pixel, the arithmetic operation on all the pixels in the element, and the frame operation of the silicon opto-electronic double deck element 110.

That is, the output gain adjustment of the silicon opto-electronicsugmenting device 110 can control the output gain by decreasing the applied voltage when the output gain of all the pixels of the silicon opto-electronic equalizer device 110 is saturated.

4 is a graph showing a correlation between an applied voltage and an output gain in the silicon opto-electronic double-twister 110 according to an embodiment of the present invention.

The plurality of linear graphs shown in FIG. 4 are obtained by measuring an output gain according to an applied voltage for each of the plurality of silicon opto-electronic expansion vessel elements 110 from the same wafer.

In the case of the silicon photomultiplier element 110, the output gain (Gain, G) in the operating region is linearly proportional to the applied voltage (Voltage, V). Due to this linear relationship, the output gain can be easily adjusted by varying the voltage output from the silicon opto-electronics booster device 110.

One embodiment of the present invention may also be embodied in the form of a recording medium including instructions executable by a computer, such as program modules, being executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Output gain control device of a silicon optoelectronic device
110: Silicon photomultiplier tube device
120: Analog signal processor
130: Digital signal processor
140:

Claims (6)

An output gain control apparatus for a silicon optoelectronic device,
An analog signal processor for converting the incident light incident on the silicon opto-electronic expansion tube device into an analog voltage signal,
A digital signal processor for receiving the analog voltage signal from the analog signal processor and converting the analog voltage signal into a digital signal;
And a control unit for controlling the digital signal processing unit and the silicon photomultiplier device,
Wherein the control unit receives the digital signal from the digital signal processing unit and compares the received digital signal with a threshold value and decreases the voltage output from the silicon photomultiplier device when the digital signal exceeds the threshold value, Wherein the output gain of the silicon photomultiplier element is controlled by adjusting the output gain of the silicon photomultiplier tube. The method according to claim 1,
Wherein the control unit performs an operation for each pixel of the silicon photomultiplier element, an operation for all the pixels in the element, and a plurality of frame operations to adjust an output gain of the silicon photomultiplier element. 3. The method of claim 2,
Wherein the control unit adjusts an output gain by reducing a voltage output from the silicon photomultiplier element when an output gain of all the pixels of the silicon optoelectronic multipier device is saturated, . A method of controlling an output gain of a silicon opto-electronic multiplier device through an output gain control device of a silicon optoelectronic multiplier device,
Converting the incident light incident on the silicon optoelectronic device into an analog voltage signal,
Converting the converted analog voltage signal into a digital signal,
Comparing the digital signal to a threshold; and
Adjusting the output gain of the silicon opto-electronic equalization device according to a comparison result of the digital signal and a threshold value,
Wherein adjusting the output gain of the silicon photomultiplier element comprises:
Wherein when the digital signal exceeds the threshold value, a voltage output from the silicon photomultiplier element is reduced to adjust an output gain of the silicon optoelectronic multipier device. 5. The method of claim 4,
The step of adjusting the output gain of the silicon opto-
Wherein the output gain of the silicon photomultiplier device is controlled by performing an operation on each pixel of the silicon photomultiplier element, an operation on all pixels in the element, and a plurality of frame operations. 6. The method of claim 5,
The step of adjusting the output gain of the silicon opto-
Wherein when the output gain of all the pixels of the silicon photomultiplier device is saturated, a voltage output from the silicon optoelectronic multipier device is reduced to adjust an output gain.

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