JP2012181098A - Optical intensity spectrum measuring method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical intensity spectrum measuring method and device that are capable of achieving high-wavelength resolution and high-speed measurement simultaneously.SOLUTION: An optical intensity spectrum measuring device comprises; a wavelength component resolution element (1003) for spatially resolving input light for each wavelength component and generating resolved light after spatial resolution for each wavelength component; a half mirror (1004) for dividing the resolved light into multiple divided light rays; multiple light-receiving element arrays (1005 and 1006) with slits (1007 and 1008) for respectively receiving the divided light rays; and an optical intensity spectrum configuration part (1009) for generating optical intensity spectrum information of the input light from an optical intensity signal for each wavelength component that is respectively detected by the light-receiving element arrays with slits. In each of the light-receiving element arrays with slits, each wavelength component of the divided light rays to be received changes in the same direction as an array direction of each light-receiving element, and each slit translucent part narrower than a light-receiving surface of the light-receiving element is provided at a position different in each light-receiving element in the array direction.

Description

  The present invention relates to a light intensity spectrum measurement technique for input light, and more particularly to a method and apparatus for measuring a light intensity spectrum of spatially wavelength-resolved light.

  In recent years, with the need for high-speed and large-capacity communication, optical communication with a transmission rate per channel exceeding 10 Gbps has been put into practical use in optical digital communication, and research and development of optical communication exceeding 100 Gbps has become active. In an ultra-high-speed optical digital communication system exceeding 40 Gbps, signal waveform distortion due to polarization dispersion occurring in a transmission path has a great influence on reception quality. The reason why polarization dispersion is regarded as a factor of waveform distortion of an optical transmission signal is that generation of polarization dispersion is a random process and changes at high speed, so that it is difficult to avoid and develop compensation technology. Therefore, it is increasingly important to monitor the occurrence of polarization dispersion in detail in real time.

  As a method for monitoring polarization dispersion in detail, there is a method using a wavelength-resolved Stokes vector. The wavelength-resolved Stokes vector is measured by applying a light intensity spectrum measurement. However, in order to realize a detailed polarization dispersion monitor in real time, it is indispensable to measure the light intensity spectrum at high speed and with high wavelength resolution.

  The wavelength-resolved Stokes vector is measured by measuring the Stokes vector for each wavelength component included in a desired optical signal with a finite wavelength resolution. The measurement method includes a wavelength batch method as described in Patent Document 1 and a wavelength scan method as described in Patent Document 2. In any system, the input light is basically spatially wavelength-resolved by a wavelength resolving element such as a diffraction grating and the light intensity for each wavelength component is measured. In the collective wavelength method, a large number of light receiving elements are prepared, and light signals spatially wavelength-resolved are made incident thereon, thereby obtaining light intensities having different wavelength components for each light receiving element. On the other hand, in the wavelength scanning method, wavelength components are sequentially incident on one light receiving element to obtain light intensity for each wavelength component.

Japanese Patent No. 4563828 JP-A-11-271143

  However, none of the wavelength batch method and wavelength scan method described above can achieve both high-speed measurement and high wavelength resolution, as described below.

  In the wavelength batch method, the wavelength components can be measured all at once, so that all wavelength components can be measured in about several μsec, and high-speed measurement is possible. In this system, the wavelength resolution is limited by the area of each light receiving element in the light receiving element array, and a higher wavelength resolution can be expected as the area of the light receiving element is smaller. In the 1.5 μm band for long-distance optical communication, an optical sensor made of InGaAs is used for the light receiving element array. However, since it is difficult to finely process InGaAs, there is currently an optical sensor manufactured by Hamamatsu Photonics Co., Ltd. (http://jp.hamamatsu.com/products/sensor-ssd). /pd101/pd109/index_en.html), and a pixel size of about 30 μm × 30 μm is the minimum. Although it depends on the performance of the wavelength resolving element to be used, the wavelength resolution that can be achieved when the side of the light receiving element area is 30 μm is about 100 pm.

  The wavelength scanning method measures the resolved wavelength components in order, so it takes about several milliseconds to measure all wavelength components. However, since the wavelength components are measured sequentially, the input beam diameter to the light receiving element array is slit. A high wavelength resolution can be realized by narrowing down by, for example. Although depending on the performance of the wavelength resolving element to be used, the wavelength resolution achievable when a slit having a width of 10 μm is used is approximately 10 pm.

  In order to accurately measure the wavelength-resolved Stokes vector, it is necessary to achieve both high-speed measurement and high wavelength resolution. If the wavelength resolution is insufficient, the wavelength-resolved Stokes vector cannot be measured correctly, and the calculated polarization dispersion amount error becomes large. Further, if the measurement takes time, the polarization state fluctuates in the middle of the measurement, so that correct wavelength-resolved Stokes vector measurement cannot be performed, and the resulting polarization dispersion amount error increases.

  In order to perform polarization dispersion measurement including high-order components in real time in long-distance and large-capacity optical communication, it is necessary to measure the light intensity spectrum at high speed in the order of μsec and with high wavelength resolution of the order of pm. However, if priority is given to high speed, a device that can be used as described above can only achieve a wavelength resolution of about 1/100 to 1/1000 of the requirement. If wavelength resolution is prioritized, only a speed of about 1/1000 can be realized with respect to the request. For this reason, speeding up and high wavelength resolution are in a trade-off relationship, and at the same time, it has been difficult to achieve with the current technology.

  Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a light intensity spectrum measurement method and apparatus capable of achieving both high wavelength resolution and high speed measurement.

  A light intensity spectrum measuring apparatus according to the present invention includes a wavelength component decomposing unit that spatially decomposes the input light into wavelength components and generates decomposed light that is spatially decomposed into wavelength components, and branches the decomposed light into a plurality of branched lights. Branching means, a plurality of light receiving element arrays with slits that individually receive the plurality of branched lights, and a light intensity signal for each wavelength component detected by each of the plurality of light receiving element arrays with slits. A light intensity spectrum generating means for generating light intensity spectrum information, each of the plurality of light receiving element arrays with slits, the wavelength component change direction of the branched light to be received and the array direction of the light receiving elements match, The position of the slit translucent portion narrower than the light receiving surface with respect to the light receiving surface of each light receiving element in the array direction differs for each light receiving element array with a slit. The features.

  In the light intensity spectrum measurement method according to the present invention, the wavelength component resolving means spatially decomposes the input light for each wavelength component to generate decomposed light spatially decomposed for each wavelength component, and the branching means splits the decomposed light into a plurality of branches. A plurality of light receiving element arrays with a plurality of slits receive the plurality of branched lights separately through the slits, and a light intensity spectrum generating means for each wavelength component detected by the plurality of light receiving element arrays with the slits. Light intensity spectrum information of the input light is generated from the light intensity signal, and in each of the plurality of light receiving element arrays with slits, the wavelength component change direction of the branched light received, the array direction of the light receiving elements, and the slit light transmission of the slits The slit direction is narrower than the light receiving surface with respect to the light receiving surface of each light receiving element in the array direction. Position is different for each slit light receiving element arrays, it is characterized.

  According to the present invention, it is possible to achieve both high wavelength resolution and high speed measurement in light intensity spectrum measurement.

FIG. 1A is a schematic configuration diagram of a light intensity spectrum measuring apparatus according to an embodiment of the present invention, and FIG. 1B is a positional relationship between an array pattern of light transmitting portions of a slit and a corresponding light receiving element array. It is a typical top view of the slit which shows. FIG. 2 is a schematic configuration diagram of a light intensity spectrum measuring apparatus according to the first embodiment of the present invention. FIG. 3A is a schematic plan view of a slit showing the positional relationship between the arrangement pattern of the light passage openings of the slit and the corresponding light receiving element array, and FIG. 3B is an equivalent light receiving element array of the light receiving element array. FIG. 3C is a schematic diagram showing an actual light receiving surface arrangement of the light receiving element array. FIG. 4 is an explanatory view showing the relationship between the wavelength and position of the light receiving element array and the slit and the branched light spatially wavelength-resolved. FIG. 5 is a schematic configuration diagram of a light intensity spectrum measuring apparatus according to a second embodiment of the present invention.

  According to the present invention, the light obtained by spatially decomposing the input light for each wavelength component is branched into a plurality of branched lights, and the plurality of light receiving element arrays with slits for receiving the plurality of branched lights separately are arranged. . In this light receiving element array with slits, the wavelength component change direction of the received branched light coincides with the array direction of the light receiving elements, and the position of the slit translucent portion narrower than the light receiving surface relative to the light receiving surface of each light receiving element is the slit. Different for each light receiving element array. By synthesizing the light intensity signals detected by the plurality of light receiving element arrays with slits having such a slit configuration, a high wavelength resolution can be obtained, and the light intensity signals can be simultaneously transmitted by the plurality of light receiving element arrays. Therefore, high speed measurement is possible. Hereinafter, embodiments and examples of the present invention will be described in detail.

1. One Embodiment Hereinafter, in order to avoid the complexity of the description, a light intensity spectrum measuring device provided with two light receiving element arrays with slits will be exemplified and one embodiment of the present invention will be described. Of course, the present invention is applicable even when n (n> 2) light receiving element arrays with slits are mounted.

  As shown in FIG. 1A, an optical signal input from an optical fiber 1001 is converted into parallel light by a lens 1002, and the parallel light is spatially decomposed for each wavelength component by a wavelength resolving element 1003. That is, since the output position varies depending on the wavelength component, if the relationship between the wavelength component and the output position is known in advance, the light intensity spectrum of the input optical signal can be measured by examining the received light intensity for each position. . This is one of the widely known light intensity spectrum measurement methods.

  The wavelength-resolved optical signal is branched by a half mirror 1004. One branched light is directed to a light receiving element array 1005 having a slit 1007 on the light receiving surface, and the other branched light is a light receiving element having a slit 1008 provided on the light receiving surface. It enters the array 1006. That is, these two branched lights are partially blocked by the slits 1007 and 1008 and then received by the light receiving element arrays 1005 and 1006. Since the branched light is spatially wavelength-resolved, the light intensity detected by each light receiving element of the light receiving element arrays 1005 and 1006 can be obtained by associating the light receiving element positions and wavelength components of the light receiving element arrays 1005 and 1006 in advance. Thus, the light intensity spectrum of the input light can be obtained.

  Each light receiving element of the light receiving element array 1005 outputs an electric signal corresponding to the intensity of the incident light to the light intensity spectrum constituting unit 1009. Similarly, each light receiving element of the light receiving element array 1006 outputs an electric signal corresponding to the intensity of the incident light to the light intensity spectrum constituting unit 1009. The light intensity spectrum configuration unit 1009 combines the light intensities of the wavelength components received by the light receiving element arrays 1005 and 1006, and calculates and reconstructs the light intensity spectrum of the input light from the optical fiber 1001.

  According to this embodiment, high wavelength resolution is obtained by reducing the effective light receiving area of each light receiving element of the light receiving element arrays 1005 and 1006. That is, slits 1007 and 1008 are provided on the light receiving surfaces of the light receiving element arrays 1005 and 1006, respectively, and the wavelength component incident on each light receiving element is limited to achieve high wavelength resolution. The wavelength component that cannot be received by the shadow of the slit 1007 of one light receiving element array 1005 can be measured using the slit 1007 of another light receiving element array 1006.

  Specifically, as shown in FIG. 1B, a light receiving element array 1005 and a light receiving element array 1006 in which the same number of light receiving elements having the same light receiving area are arranged are prepared, and a light transmitting portion is provided on each light receiving surface side. And slits 1007 and 1008 arranged in a state where the phases of the light shielding portions are reversed. In other words, each of the light receiving elements of the light receiving element array 1005 receives light on the right half (1/2) light receiving surface with respect to the paper surface of FIG. The surface is behind the slit. On the other hand, due to the slit 1008, each light receiving element of the light receiving element array 1006 has a right half (1/2) shaded by the slit and a left half (1/2) light receiving surface with respect to the paper surface of FIG. Receive light. Therefore, the branched light detected by the light receiving element array 1005 is a wavelength component corresponding to the position of the light transmitting part of the slit 1007, and the branched light detected by the light receiving element array 1006 is the position of the light transmitting part of the slit 1008 (that is, This is a wavelength component corresponding to the position of the light shielding portion of the slit 1007. By combining the light intensities of the wavelength components received by the light receiving element arrays 1005 and 1006, all wavelengths of the input light from the optical fiber 1001 can be covered, and the wavelength resolution as a whole is improved twice.

  Here, the wavelength resolution is doubled by limiting the wavelength component by the slit to 1/2 of the light receiving element area, but the wavelength resolution is not limited to twice. By changing the area ratio 1 / n between the light shielding part and the light transmitting part of the slit (n is an integer of 3 or more), a wavelength resolution of n times can be theoretically obtained. However, when the input light is doubled, the input light is divided into two and the number of light receiving element arrays is doubled, and when the input light is tripled, the input light is branched into three and the number of light receiving element arrays is increased three times. Therefore, the number of branches and the number of light receiving element arrays must be increased by a factor of n to obtain a wavelength resolution of 1. Therefore, the mounting difficulty increases as n increases.

  As described above, according to the present embodiment, the wavelength resolution can be improved. However, since the wavelength components of the input light are simultaneously measured by the plurality of light receiving element arrays, the measurement can be speeded up. .

2. First Embodiment The light intensity spectrum measuring apparatus shown in FIG. 2 uses a diffraction grating 2003 as the wavelength resolving element 1003 in FIG. 1, and an analog-to-digital converter (ADC) 2009 and an FPGA (Field) as the light intensity spectrum component 1009. This is an example in which Programmable Gate Array) 2010 is used. FIG. 3 shows the positional relationship between each light receiving element and the slit in the light receiving element array 2005 and the light receiving element array 2006, and also shows the relationship between the position and the wavelength component. Further, FIG. 4 shows the positional relationship among the optical signal beam 2011, the slit 2007, and the light receiving element array 2005 branched by the half mirror 2004, and the relationship between the position and the wavelength component. The operation of the light intensity spectrum measuring apparatus that simultaneously realizes high speed and high wavelength resolution will be described in detail below with reference to FIGS.

  The basic operation is the same as in FIG. That is, an optical signal input from the optical fiber 2001 is converted into parallel light by the lens 2002, and the parallel light is spatially decomposed for each wavelength component by the diffraction grating 2003. The wavelength-resolved optical signal is branched by a half mirror 2004. One branched light is directed to a light receiving element array 2005 having a slit 2007 on the light receiving surface, and the other branched light is a light receiving element having a slit 2008 provided on the light receiving surface. Incident on the array 2006. The light intensity signals output from the light receiving element arrays 2005 and 2006 are digitally converted by the ADC 2009 and synthesized by the FPGA 2010 to obtain a light intensity spectrum of the input light.

  Hereinafter, with reference to FIG. 3 and FIG. 4, the positional relationship of each light receiving element of a slit and a light receiving element array, and the relationship between a position and a wavelength are demonstrated in detail.

  In the light receiving element array 2005 having the slit 2007, a large number of light receiving surfaces 2013 of the light receiving elements of the light receiving element array 2005 are arranged in a line as shown in FIG. Hereinafter, the light receiving area of each light receiving element is represented by Se.

As shown in FIG. 3A, the position of the light receiving element array 2005 is adjusted by the slit 2007 so that the light receiving area of each light receiving element is halved. Moreover, for a spatially wavelength separated light signal by the diffraction grating 2003, ₁ wavelength components lambda can be received through the slit _{2007, ..., λ 2i-1} , ..., so that the lambda _2n-1 The positions of the diffraction grating 2003, the slit 2007, and the light receiving element array 2005 are adjusted. Similarly, ₂ wavelength components lambda can be received through the slit 2008, ..., lambda _2i, ..., diffraction grating 2003 so that the lambda _2n, the position of the slit 2008 and the light receiving element array 2006 is adjusted. By using two sets of light receiving element arrays with slits 2005 and 2006 adjusted in position in this way, the light receiving area of each light receiving element is actually Se, but effectively Se as shown in FIG. A light receiving element array 2012 equivalent to a light receiving element array having a light receiving area of / 2 is obtained.

  The spatially wavelength-resolved optical signal beam input from the half mirror 2004 to the light receiving element array 2005 with the slit 2007 changes its output azimuth for each wavelength by the diffraction grating 2003. Therefore, as shown in FIG. The shape spreads in the longitudinal direction. In addition, since the wavelength component included differs depending on the position imaged in the slit 2007, which light receiving element of the light receiving element array 2005 receives the light when it is received by the light receiving element array 2005 through the slit 2007. If the information and the wavelength information are known in advance, the light intensity spectrum can be measured by measuring the received light intensity. The operation is the same for the light receiving element array 2006 having the slit 2008. Since the light intensity spectra measured by the light receiving element arrays 2005 and 2006 each contain only half the wavelength component, it is necessary to reconstruct the light intensity spectrum later.

Here, lambda ₁ as described above a wavelength component of the input _{light, λ 2, ..., λ 2i} -1, λ 2i, ..., λ 2n-1, and lambda _2n. In this case, the wavelength resolution can be expressed as Δλ = λ _2i −λ _2i−1 . Since the input light is spatially wavelength-resolved, by adjusting the position of the slit 2007, the wavelength components of the optical signal input to the light receiving element array 2005 are λ ₁ ,..., Λ _{2i−1,. 2n-1} can be obtained. On the other hand, by adjusting the position of the slit 2008, ₂ wavelength components of the optical signal input to the light receiving element array 2006 is lambda, ..., lambda _2i, ..., it can be made to be lambda _2n. Therefore, by using both the light receiving element arrays 2005 and 2006, it is possible to detect all wavelength components of the input light.

  What should be noted here is the wavelength resolution Δλ. Since the optical signals input to the light receiving element arrays 2005 and 2006 are spatially wavelength-resolved, the wavelength resolution of the measured light intensity spectrum is the size of the light receiving area of the light receiving elements of the light receiving element arrays 2005 and 2006. It depends on. In other words, the wavelength resolution of the light intensity spectrum measured is determined by how finely the spatially wavelength-resolved input light is detected after being resolved.

  For example, it is assumed that the light receiving element array 2005 whose total light receiving area is Sa is composed of 100 light receiving elements whose light receiving area is Se (Sa = 100 × Se), and Sa corresponds to the wavelength band Λ to be measured. Suppose you are. The wavelength resolution Δλ in this case corresponds to Se, and Δλ = Λ / 100.

  In contrast, in this embodiment, since the slits 2007 and 2008 are provided in front of the light receiving element arrays 2005 and 2006, the wavelength components of the optical signals input to the light receiving element arrays 2005 and 2006 are limited. Specifically, in the light receiving element array 2005, since the light receiving area of the light receiving element is limited to ½ by the slit 2007, the effective light receiving area Se ′ is Se ′ = Se / 2, and Sa = 100 × Se. '/ 2. Since Sa corresponds to Λ and Sa is divided by Se ′, the wavelength resolution is Δλ = Λ / 200, which is twice the wavelength resolution.

  However, since a wavelength component that cannot be received due to the shadow of the slit 2007 is generated, the light intensity is received by the light receiving element array 2006 similarly configured to double the wavelength resolution and the light intensity of all wavelength components. Can be measured.

Specifically, from the light receiving element array 2005, λ ₁ ,..., Λ _2i-1 ,..., Λ _2n-1 (odd number) component light intensity, and from the light receiving element array 2006, λ _{2 ,.} The λ _2n (even number) component light intensity is input to the ADC 2009 as an analog voltage value. The ADC 2009 converts each input analog voltage value into a digital value and outputs the digital value to the FPGA 2010. FPGA2010 is, lambda ₁ rearranges the odd component light intensity and even component light intensity input from _{ADC2009, λ 2, ..., λ} 2i-1, λ 2i, ..., constitute the λ _2n-1, λ _2n, total It is possible to obtain a light intensity spectrum in the wavelength range.

  In the present embodiment, in the light intensity spectrum measurement with high wavelength resolution as described above, the wavelength components of the input light are simultaneously measured. Therefore, it is possible to perform light intensity spectrum measurement that simultaneously realizes high speed and high wavelength resolution.

3. Second Embodiment A light intensity spectrum measuring apparatus according to a second embodiment of the present invention shown in FIG. 5 has a wavelength resolution four times as high. The difference from the first embodiment shown in FIG. 2 is that the slit-passing wavelength component is 1/4 and four light receiving element arrays with slits are used. This is because the wavelength component input to each light receiving element of the light receiving element array needs to be limited to ¼ of the light receiving element area in order to increase the wavelength resolution by four times. For this reason, the wavelength components that cannot be received by the slit increase to 3/4, so that four sets of light receiving element arrays with slits are required.

  In order to obtain four branched lights, the spatially wavelength-resolved optical signal branched into two by the half mirror 3004 is further branched into two by the half mirrors 3104 and 3204, respectively. One of the branched lights branched by the half mirror 3104 enters the light receiving element array 3105 through the slit 3107, and the other enters the light receiving element array 3106 through the slit 3108. Similarly, one of the branched lights branched by the half mirror 3204 enters the light receiving element array 3005 through the slit 3007, and the other enters the light receiving element array 3006 through the slit 3008. Since the positional relationship between the slits 3007, 3008, 3107 and 3108, the light receiving element arrays 3005, 3006, 3105 and 3106 and the optical signals spatially wavelength-resolved is as described above, the description thereof is omitted.

  A modification of the second embodiment can be configured as follows. That is, if two sets of light receiving element arrays with slits are left and the slit passing wavelength component is 1/4, the obtained wavelength component is 1/2. It is also possible to estimate the missing wavelength component from the obtained wavelength component by interpolating the adjacent wavelength component data with the FPGA 3010. However, it should be noted that the wavelength resolution may not be four times as expected because the error increases when the change in the light intensity spectrum is large. This configuration is effective when it is known in advance that the change in the light intensity spectrum to be measured is not so large.

4). Effects According to the first and second embodiments of the present invention described above, the following effects can be obtained.

  The first effect is that high speed and high wavelength resolution can be realized simultaneously. The reason is that high wavelength resolution can be achieved by providing a plurality of light receiving element arrays with slits in a wavelength batch method that allows high-speed measurement but difficult to achieve high wavelength resolution.

  The second effect is that it can be realized at low cost. The reason is that in order to achieve high wavelength resolution, it is necessary to reduce the light receiving element area of the light receiving element array, but in order to realize this, large-scale technology development and capital investment are required. However, this is because it can be realized simply by limiting the light receiving element area by providing a slit.

  The third effect is easy to realize. The reason is that the device to be configured is currently commercially available.

  The fourth effect is high extensibility. This is because a desired wavelength resolution can be designed by changing the slit passage area.

  The fifth effect is that the application range is wide. The reason is that the region where the light intensity spectrum is expected to be measured at high speed and with high wavelength resolution is not limited to the real-time polarization dispersion monitor, but can be applied in various ways such as device property evaluation and tomography. is there.

  The present invention can be applied to wavelength-resolved Stokes vector measurement, polarization dispersion monitor, or device physical property evaluation.

1001 Optical fiber 1002 Lens 1003 Wavelength component resolving element 1004 Her mirror 1005, 1006 Light receiving element array 1007, 1008 Slit 1009 Light intensity spectrum component 2001 Optical fiber 2002 Lens 2003 Diffraction grating 2004 Half mirror 2005, 2006 Light receiving element array 2007, 2008 Slit 2009 A / D converter 2010 FPGA
2011 wavelength-resolved beam diameter 2012 equivalent light receiving pixel pitch 2013 actual light receiving pixel pitch 3001 optical fiber 3002 lens 3003 diffraction grating 3004, 3104, 3204 half mirror 3005, 3006, 3105, 3106 light receiving element array 3007, 3008, 3107 3108 Slit 3009, 3109 A / D converter 3010 FPGA

Claims (10)

An apparatus for measuring a light intensity spectrum of input light,
Wavelength component decomposition means for spatially resolving the input light for each wavelength component and generating decomposed light spatially decomposed for each wavelength component;
Branching means for branching the decomposed light into a plurality of branched lights;
A plurality of light receiving element arrays with slits for separately receiving the plurality of branched lights, and
A light intensity spectrum generating means for generating light intensity spectrum information of the input light from a light intensity signal for each wavelength component detected by each of the plurality of light receiving element arrays with slits;
Each of the plurality of light receiving element arrays with slits has a wavelength component change direction of the branched light to be received and an array direction of the light receiving elements, and the light receiving surface with respect to the light receiving surface of each light receiving element in the array direction A light intensity spectrum measuring apparatus, characterized in that the position of the narrower slit light transmitting portion is different for each light receiving element array with a slit.   The branching unit branches the decomposed light into n (n is an integer of 2 or more) branched light, and in each light receiving element of each light receiving element array, the slit light transmitting portion is 1 of the light receiving surface of the light receiving element. The light intensity spectrum measuring apparatus according to claim 1, wherein the light intensity spectrum measuring apparatus is disposed at a position that does not overlap with a slit light transmitting portion that has a spacing of / n and has a spacing of 1 / n in another light receiving element array.   3. The light intensity spectrum measuring device according to claim 2, wherein n is 2 or 4. The branching unit branches the decomposed light into n (n is an integer of 2 or more) branched light, and in each light receiving element of each light receiving element array, the slit light transmitting portion is 1 of the light receiving surface of the light receiving element. / M (m> n) and is disposed at a position that does not overlap with the slit light-transmitting part having the interval of 1 / m in the other light receiving element arrays,
The light intensity spectrum generating means generates light intensity spectrum information of the input light by interpolation from light intensity signals for each wavelength component detected by the plurality of light receiving element arrays with slits,
The light intensity spectrum measuring apparatus according to claim 1. A method for measuring a light intensity spectrum of input light,
Wavelength component decomposition means spatially decomposes the input light for each wavelength component to generate decomposed light that is spatially decomposed for each wavelength component,
A branching means branches the decomposed light into a plurality of branched lights,
A plurality of light receiving element arrays with slits receive the plurality of branched lights separately through the slits,
A light intensity spectrum generating means generates light intensity spectrum information of the input light from a light intensity signal for each wavelength component detected by each of the plurality of light receiving element arrays with slits,
In each of the plurality of light receiving element arrays with slits, the wavelength component change direction of the branched light to be received, the array direction of the light receiving elements, and the arrangement direction of the slit light transmitting portions of the slits match, A light intensity spectrum measuring method, wherein a position of a slit light transmitting portion narrower than the light receiving surface with respect to the light receiving surface of the light receiving element is different for each light receiving element array with a slit.   The branching unit branches the decomposed light into n (n is an integer of 2 or more) branched light, and in each light receiving element of each light receiving element array, the slit light transmitting portion is 1 of the light receiving surface of the light receiving element. 6. The light intensity spectrum measuring method according to claim 5, wherein the light intensity spectrum measuring method is arranged at a position that does not overlap with a slit light transmitting portion having an interval of / n and having an interval of 1 / n in another light receiving element array.   7. The light intensity spectrum measurement method according to claim 6, wherein n is 2 or 4. The branching unit branches the decomposed light into n (n is an integer of 2 or more) branched light, and in each light receiving element of each light receiving element array, the slit light transmitting portion is 1 of the light receiving surface of the light receiving element. / M (m> n) and is disposed at a position that does not overlap with the slit light-transmitting part having the interval of 1 / m in the other light receiving element arrays,
The light intensity spectrum generating means generates light intensity spectrum information of the input light by interpolation from light intensity signals for each wavelength component detected by the plurality of light receiving element arrays with slits,
The light intensity spectrum measuring method according to claim 5.   A wavelength-resolved Stokes vector measurement device using the light intensity spectrum measurement device according to claim 1.   A polarization dispersion monitor using the wavelength-resolved Stokes vector measurement device according to claim 9.

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