Optical spectrum analyzer and measurement method

Abstract

To measure light to be measured of two channels in a short time.SOLUTION: An optical spectrum analyzer comprises: a control part (9); an incident part (1); a diffraction grating (3); a light reception part (7); and a measurement part (8). The incident part (1) comprises: first incident means (1a) for emitting first light to be measured (ChA); and second incident means (1b) for emitting second light to be measured (ChB). The light reception part comprises: first light reception means (7a) receiving diffraction light of the first light to be measured; and second light reception means (7b) for receiving diffraction light of the second light to be measured. The measurement part performs first measurement for measuring wavelength components of the first light to be measured and of the second light to be measured concurrently, and if there is a wavelength range for which measurement cannot be performed, performs second measurement for measuring a wavelength range including the wavelength range of the first or second light to be measured for which the measurement cannot be performed and being narrower than the set wavelength range of the light to be measured again. The control part complements the measurement data of the first measurement on the basis of the data of the second measurement.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an optical spectrum analyzer and a measurement method. [Background technology]

[0002] Patent Document 1 relates to a monochromator in which the light to be measured is made incident twice on a diffraction grating, and in particular describes a monochromator that improves wavelength tuning between two paths and realizes a compact and simplified device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3274035 Summary of the Invention [Problem to be solved by the invention]

[0004] In a two-channel input optical spectrum analyzer, the light to be measured in the second channel may be input while the light to be measured in the first channel is being measured. In such a case, it was necessary to restart the measurement of the light to be measured in the second channel from the beginning. However, restarting the measurement of the light to be measured in the second channel takes time.

[0005] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an optical spectrum analyzer and a measurement method that are capable of measuring two channels of light under measurement in a short period of time. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, an optical spectrum analyzer and a measurement method according to the present invention are characterized by the following [1] to [3]. [1] An optical spectrum analyzer comprising: a control unit (9); an input unit (1) for emitting light to be measured; a rotatable diffraction grating (3) for dispersing and spectroscopically dividing the light from the input unit; a light receiving unit (7) for receiving light diffracted by the diffraction grating; and a measurement unit (8) for measuring wavelength components of the light to be measured based on an output signal from the light receiving unit, the incidence unit includes a first incidence means (1a) for emitting a first light to be measured (ChA) and a second incidence means (1b) for emitting a second light to be measured (ChB); the light receiving unit includes a first light receiving means (7a) for receiving diffracted light of the first measured light, and a second light receiving means (7b) for receiving diffracted light of the second measured light, The measurement unit includes: performing a first measurement in which the diffraction grating is rotated to measure wavelength components of the first measured light and the second measured light in parallel; If there is a wavelength range that could not be measured, a second measurement is performed in which a wavelength range including the wavelength range of the first or second measured light that could not be measured and which is narrower than the set wavelength range for the measured light is swept again to measure the wavelength components, and the measurement data obtained by the first measurement is complemented based on the data obtained by the second measurement. Optical spectrum analyzer. [2] In the first measurement, when the other light under measurement is input during measurement of one of the first light under measurement and the second light under measurement, the measurement unit performs the second measurement of the other light under measurement for a wavelength range including a start wavelength of the set wavelength range to a wavelength at a time point when the other light under measurement is input. 2. The optical spectrum analyzer according to claim 1. [3] A method for measuring light to be measured by an optical spectrum analyzer, comprising the steps of: The optical spectrum analyzer includes a control unit (9), an input unit (1) that outputs light to be measured, a rotatable diffraction grating (3) that disperses and spectroscopically separates the light from the input unit, a light receiving unit (7) that receives light diffracted by the diffraction grating, and a measurement unit (8) that measures wavelength components of the light to be measured based on an output signal from the light receiving unit, the incidence unit includes a first incidence means (1a) for emitting a first light to be measured (ChA) and a second incidence means (1b) for emitting a second light to be measured (ChB); the light receiving unit includes a first light receiving means (7a) for receiving diffracted light of the first measured light, and a second light receiving means (7b) for receiving diffracted light of the second measured light, The measurement method includes: a first measuring step of measuring wavelength components of the first light under measurement and the second light under measurement in parallel by rotating the diffraction grating; a second measurement step of sweeping again and measuring wavelength components in a wavelength range including the wavelength range of the first or second measured light that could not be measured and narrower than the set wavelength range for the measured light, when there is a wavelength range that could not be measured; and a complementation step of complementing the measurement data obtained in the first measurement step based on the data measured in the second measurement step when there is a wavelength range that could not be measured. Measurement method. Effect of the Invention

[0007] According to the present invention, it is possible to measure two channels of light to be measured in a short time.

[0008] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following description of the embodiment of the present invention (hereinafter, referred to as "embodiment") with reference to the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a conceptual diagram illustrating an example of the configuration of an optical spectrum analyzer according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a conceptual diagram illustrating an outline of a measurement method according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a flow chart illustrating a measurement method according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0011] FIG. 1 is a conceptual diagram illustrating an example of the configuration of an optical spectrum analyzer according to an embodiment of the present disclosure.

[0012] The optical spectrum analyzer 100 includes an incident unit 1, a collimator 2, a diffraction grating 3, a condenser 4, a slit 5, a light receiving unit 7, a measurement unit 8, a control unit 9, a memory 10, and a display unit 11. The optical spectrum analyzer 100 may further include a first lens 6a and a second lens 6b.

[0013] The incident section 1 emits light to be measured. The incident section 1 includes a first incident means 1a for emitting a first light to be measured ChA, and a second incident means 1b for emitting a second light to be measured ChB.

[0014] The collimator 2 converts the light to be measured emitted from the entrance portion 1 into parallel light and emits it.

[0015] The diffraction grating 3 includes a motor and an encoder. The diffraction grating 3 disperses and spectroscopically separates the parallel light emitted from the collimator 2. In other words, the diffraction grating 3 disperses and spectroscopically separates the light from the incident portion 1. The diffraction grating 3 is configured to be rotatable by the motor, and sweeps from low wavelengths to high wavelengths.

[0016] The condenser 4 is composed of a lens and the like, and condenses the light diffracted by the diffraction grating 3 .

[0017] The slit 5 is disposed at a position where the diffracted light is collected by the collector 4, and transmits at least a portion of the collected light. In other words, the slit 5 transmits the light collected by the collector 4.

[0018] The first lens 6a and the second lens 6b each collect the diffracted light transmitted through the slit 5 toward the light receiving section .

[0019] The light receiving unit 7 receives the diffracted light that has passed through the slit 5. That is, the light receiving unit 7 receives the diffracted light diffracted by the diffraction grating 3. The light receiving unit 7 includes a first light receiving means 7a that receives the diffracted light of the first light to be measured ChA, and a second light receiving means 7b that receives the diffracted light of the second light to be measured ChB. The first light receiving means 7a and the second light receiving means 7b are each composed of a diode or the like.

[0020] The measuring section 8 measures the wavelength components of the light under measurement based on the output signal from the light receiving section 7 .

[0021] The control unit 9 is configured using, for example, a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), or a field programmable gate array (FPGA). The control unit 9 controls various processes in the optical spectrum analyzer 100. The control unit 9 controls, for example, the motor and encoder of the diffraction grating 3, the measurement unit 8, the display unit 11, and the like.

[0022] The memory 10 stores the programs executed by the control unit 9 and various data used during execution. The memory 10 may include a HDD, a ROM, a RAM, etc., and stores various programs (OS, application software, etc.) executed by the control unit 9 and various data.

[0023] The display unit 11 is typically a monitor or a liquid crystal screen, and displays the measurement results by the optical spectrum analyzer 100. The display unit 11 displays, for example, graphs showing the wavelength components of the first light to be measured ChA and the second light to be measured ChB.

[0024] 2 is a conceptual diagram for explaining an outline of a measurement method according to an embodiment of the present disclosure. The measurement unit 8 performs a first measurement in which the wavelength components of the first measured light ChA and the second measured light ChB are measured in parallel by rotating the diffraction grating 3. In this example, the first measurement is performed in a set wavelength range from 1300 nm to 1400 nm. However, the set wavelength range is not limited to this.

[0025] A user of the optical spectrum analyzer 100 may want to set the start timings of the two channels to be different. In that case, as shown in Fig. 2, in the first measurement, there may be a wavelength range that cannot be measured for one of the channels. For example, in the first measurement, when the wavelength of the first light to be measured, ChA, is 1310 nm during measurement, the second light to be measured, ChB, which is the other light to be measured, may be input.

[0026] If there is a wavelength range that could not be measured in the first measurement, the measurement unit 8 performs a second measurement in which the wavelength range includes the wavelength range of the first or second measured light that could not be measured and is narrower than the set wavelength range for the measured light, and sweeps again to measure the wavelength components.The control unit 9 then complements the measurement data obtained by the first measurement based on the data measured by the second measurement.

[0027] More specifically, in the first measurement, if the other measured light is input while measuring one of the first measured light ChA and the second measured light ChB, the measurement unit 8 performs a second measurement for the other measured light over a wavelength range including the start wavelength of the set wavelength range for the other measured light to the wavelength at the time the other measured light is input.

[0028] In the example shown in FIG. 2, the control unit 9 controls the motor of the diffraction grating 3 to be rewound, and then the measurement unit 8 sweeps again to perform a second measurement of the wavelength components in the wavelength range from 1300 nm to 1310 nm, which includes the wavelength range (1300 nm to 1310 nm) of the second measured light ChB that could not be measured and is narrower than the set wavelength range for that measured light.

[0029] FIG. 3 is a flow chart illustrating a measurement method according to one embodiment of the present disclosure.

[0030] The measurement unit 8 performs measurement of one channel of light to be measured (St101). That is, the measurement unit 8 rotates the diffraction grating 3 under the control of the control unit 9 to perform measurement of the wavelength component of one of the light to be measured. In this example, the one light to be measured is, for example, the first light to be measured ChA.

[0031] The control unit 9 judges whether the light to be measured of the second channel has been input (St102). If the light to be measured of the second channel has been input (St102: Yes), the process proceeds to step St105. If the light to be measured of the second channel has not been input (St102: No), the process proceeds to step St103. In this example, the light to be measured of the second channel is, for example, the second light to be measured ChB.

[0032] In step St103, the control unit 9 judges whether or not the measurement end point λend has been reached. In this example, the measurement end point λend is 1400 nm, which is the end point of the wavelength range to be measured (see FIG. 2). If the measurement end point λend has been reached (St103: Yes), the process proceeds to step St104. Note that step St104 will be described later. If the measurement end point λend has not been reached (St103: No), the process returns to step St101.

[0033] In step St105, the control unit 9 stores λmid, which is the wavelength at which measurement is switched from channel 1 to channel 2. The storage location of λmid may be, for example, the memory 10, but is not limited to this.

[0034] The measurement unit 8 performs parallel measurement of the measured light of the two channels (St106). That is, the diffraction grating 3 is rotated under the control of the control unit 9 to perform parallel measurement of the wavelength components of one measured light and the other measured light. In this example, the other measured light is, for example, the second measured light ChB.

[0035] In step St107, the control unit 9 judges whether the measurement end point λend has been reached. In this example, the measurement end point λend is 1400 nm, which is the end point of the wavelength range to be measured (see FIG. 2). If the measurement end point λend has been reached (St107: Yes), the process proceeds to step St108. ​​If the measurement end point λend has not been reached (St107: No), the process returns to step St106.

[0036] In step St108, the measurement unit 8 measures the measured light of the second channel (St108). That is, the diffraction grating 3 is rotated under the control of the control unit 9, and the measurement unit 8 measures the wavelength component of the other measured light. This measurement is called the second measurement. The second measurement is performed in the wavelength range from λstart, which is the measurement start point, to the above-mentioned λmid.

[0037] The control unit 9 complements the measurement data obtained by the first measurement based on the data obtained by the second measurement (St109).

[0038] In step St104, the control unit 9 causes the display unit 11 to display the obtained data. In this example, the obtained data is displayed in the form of a waveform on the display unit 11 as shown in Fig. 2. However, the display form is not limited to a waveform, and may be displayed as, for example, numerical values.

[0039] By carrying out the above-mentioned processing, the optical spectrum analyzer 100 according to this embodiment can measure the measured light of two channels in a short time.

[0040] Even if the optical spectrum analyzer 100 according to the present embodiment has three or more channels, it is possible to measure the measured light of multiple channels in a short time. In this case, for example, the above-mentioned measurement method may be performed on the first and second channels out of the three channels.

[0041] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or amended examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. For example, the steps in the method of the present disclosure can be performed in any order as long as there is no contradiction. In addition, the components in the above embodiments may be combined in any order as long as it does not deviate from the spirit of the disclosure. [Explanation of symbols]

[0042] 1 Input section 1a First injection means 1b Second injection means 2 Collimator 3. Diffraction Grating 4. Concentrator 5 Slit 7 Light receiving section 7a First light receiving means 7b Second light receiving means 8 Measuring part 9. Control Unit 10. Memory 11 Display section 100 Optical Spectrum Analyzer

Claims

1. An optical spectrum analyzer comprising: a control unit (9); an input unit (1) for emitting light to be measured; a rotatable diffraction grating (3) for dispersing and spectroscopically dividing the light from the input unit; a light receiving unit (7) for receiving light diffracted by the diffraction grating; and a measurement unit (8) for measuring wavelength components of the light to be measured based on an output signal from the light receiving unit, The incident unit includes a first incident means (1a) for emitting a first light to be measured (ChA) and a second incident means (1b) for emitting a second light to be measured (ChB); the light receiving unit includes a first light receiving means (7a) for receiving diffracted light of the first measured light, and a second light receiving means (7b) for receiving diffracted light of the second measured light, The measurement unit includes: performing a first measurement in which the diffraction grating is rotated to measure wavelength components of the first measured light and the second measured light in parallel; If there is a wavelength range that could not be measured, a second measurement is performed in which a wavelength range including the wavelength range of the first or second measured light that could not be measured and which is narrower than the set wavelength range for the measured light is swept again to measure the wavelength components; The control unit complements the measurement data obtained by the first measurement based on the data measured by the second measurement. Optical spectrum analyzer.

2. In the first measurement, when the other light under measurement is input during measurement of one of the first light under measurement and the second light under measurement, the measurement unit performs the second measurement for the other light under measurement in a wavelength range including a start wavelength of the set wavelength range to a wavelength at a time point when the other light under measurement is input.

2. The optical spectrum analyzer of claim 1.

3. A method for measuring light to be measured by an optical spectrum analyzer, comprising the steps of: The optical spectrum analyzer includes a control unit (9), an input unit (1) that outputs light to be measured, a rotatable diffraction grating (3) that disperses and spectroscopically separates the light from the input unit, a light receiving unit (7) that receives light diffracted by the diffraction grating, and a measurement unit (8) that measures wavelength components of the light to be measured based on an output signal from the light receiving unit. The incident unit includes a first incident means (1a) for emitting a first light to be measured (ChA) and a second incident means (1b) for emitting a second light to be measured (ChB); the light receiving unit includes a first light receiving means (7a) for receiving diffracted light of the first measured light, and a second light receiving means (7b) for receiving diffracted light of the second measured light, The measurement method includes: a first measuring step of measuring wavelength components of the first light under measurement and the second light under measurement in parallel by rotating the diffraction grating; a second measurement step of, when there is a wavelength range that could not be measured, sweeping again and measuring wavelength components in a wavelength range that includes the wavelength range of the first or second measured light that could not be measured and is narrower than the set wavelength range for the measured light; and a complementation step of complementing the measurement data obtained in the first measurement step based on the data measured in the second measurement step when there is a wavelength range that could not be measured. Measurement method.

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