JPH11237283A - Array type photodetector, spectrometer and spectrum analyzer employing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the horizontal and central positions even of a dual beam by disposing a pair of position adjusting elements at the opposite ends of an array of photodetector elements and adjusting the position of photodetectors to produce uniform detection signals. SOLUTION: One dual beam comprising light beams PB21, PB22 is condensed onto position adjusting PAE11, PAE12 arranged at one end of an array of photodetector elements E201-E204 and the other dual beam comprising light beams PB23, PB24 is condensed onto position adjusting elements PAE13, PAE14. An array type photodetector 4b is moved in x, y directions while adjusting inclination thus making uniform detection signals from the position adjusting elements PAE11, PAE12. A position where detection signals from the elements PAE13, PAE14 are made uniform is determined and the photodetector 4b is fixed thereat. According to the arrangement, the horizontal and central positions even of a dual beam can be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an array-type photodetector, and more particularly, to an array-type photodetector which can be easily positioned at the time of manufacturing, and a spectroscope and an optical spectrum analyzer using the same.

[0002]

2. Description of the Related Art A conventional array-type photodetector is a photodetector in which a plurality of slit-type photodetectors are arranged in an array, and is mainly used for a spectrometer, an optical spectrum analyzer and the like. FIG. 5 is a configuration block diagram showing an example of a spectroscopic device using such a conventional array-type photodetector. In FIG. 5, 1 is a collimating lens, 2 is a diffraction grating, 3 is a condensing mirror, 4 is an array type photodetector, 5 is an arithmetic control circuit, and 100 is incident light.

[0003] Incident light 100 is incident on a diffraction grating 2 via a collimating lens 1, and reflected light from the diffraction grating 2 is incident on a condenser mirror 3. The reflected light from the condenser mirror 3 is incident on the array-type photodetector 4, and the output signal from the array-type photodetector 4 is connected to the arithmetic and control circuit 5.

Here, the operation of the spectrometer shown in FIG.
This will be described with reference to FIG. FIG. 6 is a plan view illustrating details of the array-type photodetector 4. The incident light 100 becomes parallel light by the collimating lens and is incident on the diffraction grating 2. In the diffraction grating 2, the light is reflected by the converging mirror 3 at a different reflection angle depending on the wavelength of the incident light, and the converging mirror 4 condenses the incident light on the array type detector 4. The output signal from the array-type photodetector 4 is subjected to appropriate arithmetic processing and the like in the arithmetic control circuit 5, and the arithmetic result is displayed on a display means (not shown).

For example, “E001”, “E00” in FIG.
Reference numerals 2 "," E003 "," E004 ", and" E005 "denote photodetectors constituting the array type photodetector 4 arranged in an array. The light beam incident on the array type photodetector 4 is shown in FIG. 6, the photodetector "E" as indicated by "PB01"
001 ”and“ E002. ”Since the diffraction grating 2 reflects light at a reflection angle determined based on the wavelength of the incident light 100, the light is condensed at the position where the incident light 100 is reflected.
Is determined by the wavelength.

In other words, it is possible to measure the wavelength of the incident light 100 by identifying which light detecting element has detected the light beam “PB01”. Further, by measuring the intensity of the detection signal in the light detecting element, it is possible to measure the intensity of the incident light beam.

As a result, the incident light 100 is reflected by the diffraction grating 2 at a reflection angle determined based on the wavelength of the incident light 100, and the position of the reflected light beam focused on the array type photodetector 4 is determined. By calculating, the wavelength of the incident light 100 can be measured, and the intensity of the light beam can be measured from the intensity of the detection signal at the photodetector.

However, the size of the photodetectors is limited by the height of the photodetectors in consideration of the yield of the array type photodetector 4. In other words, since the height indicated by “H” in FIG. 6 is limited, it is necessary for the light beam indicated by “PB01” in FIG. 6 to be focused on the photodetector “E001” or the like for a long period of time. The adjustment of the center position in the “x direction” in FIG. 6 and the adjustment of the horizontal position in the “y direction” in FIG. 6 are important.

[0009] In this case, the incident light beam is shown in FIG.
There is a problem that the horizontal position of the light beam can be adjusted from the change in the intensity of the detection signal obtained by swinging in the middle "± y direction", but the center position cannot be adjusted.

FIG. 7 is a plan view showing an example of an array type photodetector in which such a problem is solved. In FIG. 7, 4
a is an improved array-type photodetector, "E10
Reference numerals 1 "," E102 "," E103 ", and" E104 "denote photodetectors constituting the array-type photodetector 4a arranged in an array, and" PAE01 "and" PAE ".
02 "is a light beam position adjusting light detecting element provided at both ends of the light detecting element (hereinafter, simply referred to as a position adjusting element).
It is.

In the array type photodetector 4a as shown in FIG. 7, the horizontal position and the center position of the light beam can be adjusted in the following manner. That is, the two light beams “PB11” and “PB12” for position adjustment are changed to “position adjustment elements”.
The light is condensed on PAE01 "and" PAE02 ", respectively, and the position of the array-type photodetector 4a is set to" x direction "and" y "in FIG.
The array type photodetector 4a is fixed by moving in the direction "" or adjusting the tilt to find a position where the detection signals of the position adjusting elements "PAE01" and "PAE02" are both maximum.

As a result, the position adjusting elements are provided at both ends of the light detecting elements, and the position of the array type photodetector 4a is adjusted so that the detection signal of these position adjusting elements is maximized. , The horizontal position and the center position can be adjusted.

[0013]

However, in the conventional example shown in FIG. 7, when the incident light beam is circular, the horizontal position and the center position of the light beam can be adjusted. There was a problem that the position of the light beam could not be adjusted when the dual beam was formed by the depolarizing plate. Therefore, an object of the present invention is to realize an array-type photodetector capable of adjusting the position of a light beam even in the case of a dual beam.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an array type photodetector comprising a plurality of photodetectors arranged in an array. , Provided at both ends of a row of these photodetectors.
By providing the first and second light beam position adjusting light detecting means constituted by a pair of light beam position adjusting light detecting elements, the horizontal position and the center position of the light beam can be adjusted even with a dual beam. It becomes possible to adjust.

According to a second aspect of the present invention, the use of the array type photodetector according to the first aspect of the present invention as a photodetector of a spectroscopic device makes it easy to adjust the position of the photodetector, thereby reducing the manufacturing cost. This makes it possible to maintain the measurement accuracy of the device for a long period of time.

According to a third aspect of the present invention, the use of the array type photodetector according to the first aspect of the present invention as a photodetector of an optical spectrum analyzer makes it easy to adjust the position of the photodetector, thereby reducing the manufacturing cost. The measurement accuracy of the device can be maintained for a long period of time.

According to a fourth aspect of the present invention, in the array-type photodetector, a plurality of photodetectors arranged in an array are provided;
By providing first and second light beam position adjusting light detecting means provided at both ends of the row of these light detecting elements and comprising two pairs of light beam position adjusting light detecting elements, Even when a malfunction occurs in the pair of position adjusting elements, the horizontal position and the center position of the light beam can be adjusted by using the remaining pair of position adjusting elements.

According to a fifth aspect of the present invention, the use of the array type photodetector according to the fourth aspect of the present invention as a photodetector of a spectroscopic device makes it easy to adjust the position of the photodetector, thereby reducing the manufacturing cost. This makes it possible to maintain the measurement accuracy of the device for a long period of time.

According to a sixth aspect of the present invention, the use of the array type photodetector according to the fourth aspect of the present invention as a photodetector of an optical spectrum analyzer makes it easy to adjust the position of the photodetector, thereby reducing the manufacturing cost. The measurement accuracy of the device can be maintained for a long period of time.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing the configuration of an embodiment of the array type photodetector according to the present invention.

In FIG. 1, reference numeral 4b denotes an array type photodetector, which includes "E201", "E201", "E203" and "E201".
E204 ”is a photodetector,“ PAE11 ”,“ PAE1 ”.
2 "," PAE13 ", and" PAE14 "are position adjusting elements, and are" E201 "," E202 "," E "in FIG.
203 "and" E204 "are arranged in an array in the" x direction "in FIG. 1, and the position adjusting elements" PAE11 "and" PAE12 "are adjacent to the photodetector" E201 "in FIG.
The light detecting element “E20” is provided side by side in the middle “y direction”.
4 "adjacent to the position adjustment elements" PAE13 "and" P
AE14 "are provided side by side in the" y direction "in FIG.

Also, a pair of position adjusting elements "PAE1"
“1” and “PAE12” correspond to the light beam position adjusting light detecting means 50 and a pair of position adjusting elements “PAE13” and “PAE12”.
The PAEs 14 "constitute light beam position adjusting light detecting means 51, respectively.

Here, the adjustment of the horizontal position and the center position of the light beam in the embodiment shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a characteristic curve diagram showing the intensity distribution of the dual beam, and FIG. 3 is a plan view showing the positional relationship between the position adjusting element and the dual beam.

In the case of a dual beam, as shown in FIG. 2, light of two wavelengths (λ1 and λ2) whose center positions of the peak intensities are shifted in the “y direction” in FIG. 1 is multiplexed. I have. However, the center positions of the peaks coincide in the “x direction” in FIG.

When adjusting the position of a light beam (dual beam), first, two dual beams for position adjustment are used, and one of the dual beams is used as a position adjustment element "PA".
E11 "and" PAE12 "are condensed, and the other dual beam is focused on the position adjusting elements" PAE13 "and" PAE1 ".
Focus on 4 ".

That is, the light beams “PB21” and “PB21”
The dual beam composed of B22 "is condensed on the position adjusting elements" PAE11 "and" PAE12 ", and the dual beam composed of the light beams" PB23 "and" PB24 "is divided into the position adjusting elements" PAE13 "and" PAE13 ". PAE
Focus on 14 ".

The array type photodetector 4b shown in FIG.
Is moved in the “x direction” and the “y direction” in FIG.
Alternatively, the position adjustment element "PAE1" is adjusted by adjusting the inclination.
The array-type photodetector 4b determines a position at which the detection signals of the position adjustment element "PAE13" and the position adjustment element "PAE14" become equal and the detection signals of the position adjustment element "PAE12" become equal. Is fixed.

In this case, for example, the position adjusting element "
The light beam “PB2” is applied to PAE11 ”and“ PAE12 ”.
The bottom portion of the intensity distribution of “1” and “PB22” is evenly spread, in other words, the central portion of one dual beam as indicated by “C” in FIG. It is located at an intermediate point with the position adjusting element “PAE12”.

Similarly, the center portion of the other dual beam is composed of the position adjusting element "PAE13" and the position adjusting element "P".
This position is located at an intermediate point with the AE 14 ″. This makes it possible to adjust the horizontal position and the center position of the light beam even with a dual beam.

As a result, a pair of position adjusting elements are provided at both ends of the light detecting element, and the position of the array type photodetector 4b is adjusted so that the detection signals of the pair of position adjusting elements become equal to each other. By doing so, it is possible to adjust the horizontal position and the center position of the light beam even with a dual beam.

FIG. 4 is a plan view showing another embodiment of the array type photodetector. In FIG. 4, reference numeral 4c denotes an array type photodetector, which is "E301", "E301", "E30".
3 "and" E304 "are photodetectors," PAE2 "
1 "," PAE22 "," PAE23 "," PAE2
4 "," PAE25 "," PAE26 "," PAE2 "
7 "and" PAE28 "are position adjusting elements.

In FIG. 4, "E301", "E30"
4, "E303" and "E304" are arranged in an array in the "x direction" in FIG. 4, and the position adjusting elements "PAE21" and "PAE2" are adjacent to the photodetector "E301".
4 are provided side by side in the "y direction" in FIG. 4, and the position adjusting elements "PAE23" and "PAE24" are adjacent to the position adjusting elements "PAE21" and "PAE22".
Are provided side by side in the “y direction” in FIG.

Similarly, the position adjusting elements "PAE25" and "PAE26" are located adjacent to the light detecting element "E304".
Are provided side by side in the "y direction", and the position adjusting elements "PAE27" and "PAE28" are adjacent to the position adjusting elements "PAE25" and "PAE26" in FIG.
They are provided side by side in the “y direction”.

The two pairs of position adjusting elements composed of the position adjusting elements "PAE21" and "PAE22" and the position adjusting elements "PAE23" and "PAE24" correspond to the light detecting means 52 for adjusting the light beam position. Adjustment element "P"
AE25 "and" PAE26 "and position adjustment element" PA "
The two pairs of position adjusting elements E27 "and" PAE28 "constitute light beam position adjusting light detecting means 53, respectively.

Here, the adjustment of the horizontal position and the center position of the light beam in the embodiment shown in FIG. 4 is basically the same as that of the embodiment shown in FIG. 1, and two pairs of position adjusting elements are provided on one side. Therefore, even if a pair of position adjustment elements have a malfunction due to, for example, a manufacturing process of an array-type photodetector, the remaining pair of position adjustment elements can be used. Thereby, the horizontal position and the center position of the light beam can be adjusted.

For example, in FIG. 4, the position adjusting element "P
If light cannot be detected due to a defect in the AE22 ", the position adjusting element" PAE21 "can be obtained even if the position of the array type photodetector 4c is adjusted by condensing a dual beam as shown by" DB01 "in FIG. The detection signals of "" and "PAE22" cannot be equalized.

In this case, the adjacent position adjusting element “PA”
By converging the dual beam on E23 "and" PAE24 "as shown by" DB02 "in FIG. 4 and equalizing the detection signals of the position adjustment elements" PAE23 "and" PAE24 "in the same manner as described above, Beam position adjustment can be performed.

Further, in the description of the embodiment shown in FIGS. 1 and 4, only the position adjustment has been described. However, the array type photodetector shown in FIGS. 1 and 4 may be replaced by a spectroscope, an optical spectrum analyzer, or the like. It is also possible to use it as a photodetector of the device described above. In this case, since the position of the photodetector is easily adjusted, the manufacturing cost can be reduced, and the measurement accuracy of the device can be maintained for a long period of time.

Further, in the description of the embodiment shown in FIGS. 1 and 4, a dual beam is exemplified. However, a position adjusting method which may be a normal single beam is described in detail below. The position of the array-type photodetector may be adjusted so that is applied evenly.

Further, in this case, it is easier to adjust the position so that the detection signals of the pair of position adjustment elements become equal, rather than adjusting the position to the maximum value of the detection signal of one position adjustment element. That is, although the latter can perform an adjustment operation capable of estimating the adjustment direction and the adjustment amount by comparing the relative detection signals, the former requires an adjustment operation after obtaining a sibling position by scanning or the like. is there.

In the embodiment shown in FIG. 4, redundancy is provided by providing two pairs of position adjusting elements on one side of the row of photodetectors, but three or more pairs of position adjusting elements are provided. Of course, it doesn't matter.

[0042]

As is apparent from the above description,
According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, a pair of position adjustment elements are provided at both ends of the photodetector, and the position of the array type photodetector is adjusted so that the detection signals of the pair of position adjustment elements are equal to each other. , The horizontal position and the center position of the light beam can be adjusted even with a dual beam.

According to the second and third aspects of the present invention, the spectrometer and the optical spectrum analyzer have the first aspect.
By using the described array-type photodetector, the position adjustment of the array-type photodetector is easy, so that the manufacturing cost can be reduced, and the measurement accuracy of the device can be maintained for a long period of time. Become.

According to the fourth aspect of the present invention, two sides are provided on one side.
By providing the pair of position adjusting elements, even when a malfunction of one pair of position adjusting elements occurs due to the manufacturing process of the array type photodetector or the like, the remaining one pair of position adjusting elements By using the position adjusting element, the horizontal position and the center position of the light beam can be adjusted.

According to the fifth and sixth aspects of the present invention, the spectrometer and the optical spectrum analyzer have the fourth aspect.
By using the described array-type photodetector, the position adjustment of the array-type photodetector is easy, so that the manufacturing cost can be reduced, and the measurement accuracy of the device can be maintained for a long period of time. Become. Further, even when a pair of position adjustment elements have a malfunction due to a manufacturing process of the array type photodetector or the like, light can be obtained by using the remaining pair of position adjustment elements. The horizontal position and the center position of the beam can be adjusted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of an array-type photodetector according to the present invention.

FIG. 2 is a characteristic curve diagram showing an intensity distribution of a dual beam.

FIG. 3 is a plan view showing a positional relationship between a position adjusting element and a dual beam.

FIG. 4 is a plan view showing another embodiment of the array type photodetector.

FIG. 5 is a configuration block diagram illustrating an example of a conventional spectroscopic device using an array-type photodetector.

FIG. 6 is a plan view illustrating details of an array-type photodetector.

FIG. 7 is a plan view showing an example of an array-type photodetector in which the problem is improved.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Collimating lens 2 Diffraction grating 3 Condensing mirror 4 Array type photodetector 5 Arithmetic control circuit 50, 51, 52, 53 Light beam position adjusting light detecting means 100 Incident light

Claims (6)

[Claims] 1. An array-type photodetector, comprising: a plurality of photodetectors arranged in an array; and a pair of photodetectors for adjusting a light beam position provided at both ends of a row of these photodetectors. An array-type photodetector comprising: a first and a second light beam position adjusting light detecting means. 2. A spectroscope using the array type photodetector according to claim 1 as a photodetector. 3. An optical spectrum analyzer using the array type photodetector according to claim 1 as a photodetector. 4. An array-type photodetector, comprising: a plurality of photodetectors arranged in an array; and two pairs of photodetectors for adjusting a light beam position provided at both ends of a row of these photodetectors. An array-type photodetector comprising: a first and a second light beam position adjusting light detecting means. 5. A spectroscopy apparatus using the array type photodetector according to claim 4 as a photodetector. 6. An optical spectrum analyzer using the array type photodetector according to claim 4 as a photodetector.