TWI719660B - Light detection device - Google Patents

Abstract

A light detecting device is suitable for detecting a light to be measured with intensity variation emitted by a light source. The light detection device includes an array spectrometer, a photodetector, and a central control unit. The array spectrometer is suitable for detecting the light to be measured and outputting a first detection signal. The photodetector is located beside the array spectrometer and is suitable for detecting the light to be measured and outputting a second detection signal. The central control unit includes an arithmetic module, and the arithmetic module performs calculations on the part of the first detection signal and the part of the second detection signal corresponding to the strong light section and the weak light section of the light to be measured, respectively Integration to obtain a light intensity change related to the light to be measured. The invention can be used to detect continuous and multiple changes of the light to be measured from the light source, and the detection is fast and sensitive.

Description

Light detection device

The present invention relates to a light detection device, in particular to a light detection device that has good detection sensitivity for both strong light and weak light and fast detection.

Array spectrometers can be used to measure light intensity, but the dynamic range of using array spectrometers to measure light intensity (Dynamic range) is affected by exposure time and light intensity. The array spectrometer performs well when used to detect strong light, but because of its low sensitivity to weak light (such as 1 lumen), when detecting weak light, it needs to extend the exposure time, but when the exposure time increases, it will increase at the same time. Measurement time and thermal noise (Thermal noise). Although it can be used with a cooling device to perform light detection and achieve the effect of suppressing thermal noise, the problem of prolonged measurement time cannot be improved, and the cooling device may reduce the measurement response of the array spectrometer. Increase the required exposure time. Therefore, how to improve the sensitivity of the measuring instrument so that it has a good detection effect for low light and can shorten the detection time is an important issue.

Therefore, the purpose of the present invention is to provide a light detection device with fast detection and high sensitivity.

Therefore, the light detecting device of the present invention is suitable for detecting a light to be measured with a change in intensity emitted by a light source. The light detection device includes an array spectrometer, a photodetector, and a central control unit.

The array spectrometer is suitable for detecting the light to be measured and outputting a first detection signal. The photodetector is located beside the array spectrometer and is suitable for detecting the light to be measured and outputting a second detection signal. The central control unit signal is connected to the array spectrometer and the photodetector, the central control unit includes an arithmetic module, and the arithmetic module corresponds to the portion of the first detection signal of a strong light section to be measured Perform calculation integration with a part of the second detection signal corresponding to a weak light section of the light to be measured to obtain a light intensity change related to the light to be measured.

The effect of the present invention is that the light intensity change related to the light to be measured is obtained by the array spectrometer, combined with the high sensitivity and rapid detection capability of the photodetector for the weak light section, so that the present invention can be used It is used to detect the continuous and multiple changes of the light to be measured from the light source, and the detection is fast and sensitive.

1: light source

2: Array spectrometer

21: photosensitive element

3: photodetector

31: Aperture

4: Light transmission unit

41: The first optical fiber module

411: First fiber

42: The second optical fiber module

421: second fiber

5: Central control unit

51: Computing Module

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: 1 is a schematic diagram of an embodiment of the light detection device of the present invention; FIG. 2 is a functional block diagram of the embodiment; FIG. 3 is a schematic diagram of an implementation of a light transmission unit of the embodiment; and 4 is a schematic diagram of the relationship between the light intensity of the light to be measured and the input power. In the figure, a first detection signal (curve 1) and a second detection signal (curve 2) are calculated and integrated to obtain a correlation The light intensity change of the light to be measured (curve 3).

Referring to Figures 1, 2, 3, and 4, an embodiment of the light detecting device of the present invention is suitable for detecting a light to be measured with a change in intensity emitted by a light source 1 (that is, the light to be measured is composed of a strong light section and A low-light section). The light detection device of this embodiment includes an array spectrometer 2, a photodetector 3, a light transmission unit 4, and a central control unit 5.

The array spectrometer 2 is suitable for detecting the light to be measured, and outputs a first detection signal (which includes a strong light section signal and a low light section signal) according to the detection result. The spectrometer 2 array detectable range of light intensity is greater than or equal to 10 ⁶ photons / sec, and therefore can be used to detect light. The array spectrometer 2 includes a plurality of photosensitive elements 21 for detecting the light to be measured. Each of the photosensitive elements 21 is a charge coupled device (CCD) or a complementary metal oxide semiconductor (Complementary Metal-oxide semiconductor). Oxide-Semiconductor, CMOS) photosensitive element, but not limited to this.

The photodetector 3 is located next to the array spectrometer 2 and is suitable for detecting the light to be measured, and outputs a second detection signal (which includes a strong light section signal and a weak light section signal) according to the detection result. In this embodiment, the photodetector 3 includes an aperture 31. After the aperture 31 first adjusts the light intensity of the weak light section of the light to be measured, the photodetector 3 then converts the adjusted light to be measured into a The electrical signal is used to detect the adjusted light to be measured to output the second detection signal. The photodetector 3 has high detection sensitivity, and has excellent and fast detection capabilities for weak light. The light intensity range that the photodetector 3 can detect is greater than or equal to 1 photon/sec and less than or equal to 10 ¹⁰ Photons per second, so it can be used to detect low light. The photodetector 3 is, for example, a photomultiplier (PMT), an avalanche photodiode (APD), or a photo sensor.

The light conducting unit 4 is suitable for conducting the light to be measured from the light source 1 to the array spectrometer 2 and the photodetector 3. In this embodiment, the light transmission unit 4 includes a first optical fiber module 41 signal-connected between the light source 1 and the array spectrometer 2, and a first optical fiber module 41 connected between the light source 1 and the photodetector 3 Two optical fiber module 42. The first optical fiber module 41 is used to transmit the light to be measured to the array spectrometer 2. The second optical fiber module 42 is used to transmit the light to be measured to the photodetector 3. It should be noted that in this embodiment, the first optical fiber module 41 includes a plurality of first optical fibers 411 (for example, including six first optical fibers 411), the second optical fiber module 42 includes one second optical fiber 421, but is not limited thereto.

The central control unit 5 signals the array spectrometer 2 and the photodetector 3. The central control unit 5 is, for example, a computer with arithmetic function, and includes an arithmetic module 51. The calculation module 51 calculates and integrates the first detection signal (curve 1 in FIG. 4) and the second detection signal (curve 2 in FIG. 4) to obtain a light intensity related to the light to be measured Change (curve 3 in Figure 4).

In detail, when the present invention is used, the light source 1 starts to emit the light to be measured. The light source 1 is, for example, a light-emitting diode, and the luminous intensity of the light source 1 changes with an input power. For example, current or voltage can be applied to the light source 1 as the input power. In this embodiment, taking the applied voltage as an example, the input power on the horizontal axis of FIG. 4 is the voltage value. The light to be measured (that is, the strong light section and the weak light section at the same time) is transmitted to the array spectrometer 2 and the photodetector 3 through the light transmission unit 4. Because the light intensity of the light to be measured varies in intensity, the present invention uses the array spectrometer 2 with the photodetector 3, both of which are sensitive to strong light and weak light, and both have a detectable range There is some overlap. When the light to be measured changes to a higher intensity and high brightness (that is, the strong light section), the first detection signal detected by the array spectrometer 2 is used as the main light intensity detection signal section In contrast, when the light to be measured changes to a lower intensity and low brightness (that is, the weak light section), the second detection signal detected by the photodetector 3 is used as the main light intensity detection Test signal section. The array spectrometer 2 After detecting with the photodetector 3, respectively output the first detection signal and the second detection signal to the central control unit 5, and the arithmetic module 51 performs the first detection signal according to a linear extrapolation method The part corresponding to the strong light section of the light to be measured and the part corresponding to the weak light section of the light to be measured in the second detection signal are calculated and integrated to obtain the complete light intensity related to the light to be measured Variety.

It should be noted that a curve 1 used to represent the first detection signal and a curve 2 used to represent the second detection signal in FIG. 4 only represent the curve driving force rather than an absolute specific value. Among them, because the array spectrometer 2 is less sensitive when detecting light with lower intensity, as shown in the curve 1, the first signal of the first detection signal fluctuates and there is more noise. Therefore, in the range of low light intensity, the measurement result of the curve 2 is the main one (that is, when the light to be measured changes to the weak light section, the second detection detected by the photodetector 3 The measurement signal is used as the main light intensity detection signal section). The calculation module 51 performs calculation correction on the first and second detection signals by the linear extrapolation method, so as to integrate the first and second detection signals to obtain the curve 3. For example, take the part of the curve 1 where the signal is good, and suppose that the light intensity signal at the circle mark in the curve 1 is read as 1, which corresponds to the light intensity signal at the circle mark in the curve 2. 10. After calculating the curves 1 and 2 by the linear extrapolation method, the point with the reading value of 9 in the curve 2 can be obtained, which is equivalent to the point with the reading value of 0.9 in the curve 1, and so on. In this way, the corresponding relationship between the curve 1 and the curve 2 can be obtained, and the curve The line 1 is mapped to the curve 2 to obtain the curve 3. It should be noted that, in the example of this embodiment, the curve 3 only presents the driving potential of the light intensity change, and is not used to represent a specific value.

In summary, from the curve 3 related to the light intensity change of the light to be measured, it can be known that the strong light section and the weak light section of the curve 3 are respectively related to the detected light intensity of the array spectrometer 2. The strong light section of the first detection signal and the weak light section of the second detection signal detected by the photodetector 3 are matched with the photodetector 3 for its high sensitivity and rapid detection of low light Therefore, it can make up for the problem that the exposure time must be prolonged in low light detection when only an array spectrometer is used to detect light in the past. Therefore, the present invention can be used to detect the continuous and multiple changes of the light to be measured from the light source 1, and can detect both the strong light and the weak light section with high sensitivity and speed. The optical detection device of the present invention that combines the array spectrometer 2 and the photodetector 3 has a fast detection time, which is more than 10 times faster than the previous detection using only an array spectrometer.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to This invention patent covers the scope.

1: light source

2: Array spectrometer

3: photodetector

4: Light transmission unit

41: The first optical fiber module

42: The second optical fiber module

5: Central control unit

51: Computing Module

Claims (9)

A light detection device suitable for detecting a light to be measured with intensity variation emitted by a light source. The light detecting device includes: an array spectrometer suitable for detecting the light to be measured and outputting a first detection signal ; A photodetector, located next to the array spectrometer, suitable for detecting the light to be measured, and output a second detection signal; a central control unit, the signal is connected to the array spectrometer and the photodetector, the central control The unit includes an arithmetic module, the arithmetic module of the first detection signal corresponding to a strong light section of the light to be measured and the second detection signal corresponding to a weak light section of the light to be measured Part of the calculation integration is performed to obtain a light intensity change related to the light to be measured; and a light transmission unit adapted to conduct the light to be measured from the light source to the array spectrometer and the photodetector. The light detection device according to claim 1, wherein the calculation module calculates and integrates the first and second detection signals according to a linear extrapolation method to obtain the light intensity related to the light to be measured Variety. The optical detecting apparatus of claim 1, wherein the array spectrometer can detect a range of light intensity is greater than or equal to 10 ⁶ photons / sec request entry. The light detection device according to claim 3, wherein the light intensity range that the photodetector can detect is greater than or equal to 1 photon/sec and less than or equal to 10 ¹⁰ photons/sec. The light detecting device according to claim 1, wherein the array spectrometer includes a plurality of photosensitive elements for detecting the light to be measured, and each of the photosensitive elements It is a photosensitive coupling element or a complementary metal oxide semiconductor photosensitive element. The light detection device according to claim 1, wherein the photodetector includes an aperture, and the aperture is used to adjust the light intensity of the low-light section of the light to be measured. The light detection device according to claim 1, wherein the photodetector is a photomultiplier tube, an avalanche photodiode, or a light sensor. The light detection device according to claim 1, wherein the light transmission unit includes a first optical fiber module, and a signal is connected between the light source and the array spectrometer for transmitting the light to be measured to the array spectrometer , And a second optical fiber module, the signal is connected between the light source and the photodetector for transmitting the light to be measured to the photodetector. The optical detection device according to claim 8, wherein the first optical fiber module includes a plurality of first optical fibers, and the second optical fiber module includes a second optical fiber.

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