Pulsed light measurement method, pulsed light measurement program, and spectrum analyzer

Abstract

The invention discloses a pulsed light measurement method, a pulsed light measurement program, and a spectrum analyzer. The pulsed light measurement method for measuring the spectrum of pulsed light includes the steps of: setting a superposition width of a wavelength for measuring light intensity in each of a plurality of scans performed in a measurement wavelength range of the spectrum; after a delay time specified based on the superposition width has elapsed from the detection of the trigger of the strobe signal synchronized with the pulsed light, each of the plurality of scans is started; and synthesizing and displaying the spectrum according to a plurality of waveforms obtained by executing multiple times of scanning.

Description

Technical Field

[0001] The present invention relates to a pulse light measurement method, a pulse light measurement program and a spectrum analyzer. Background Art

[0002] As described in Patent Document 1, a spectrum analyzer using a grating is known.

[0003] Patent Document 1: Japanese Patent No. 5339027

[0004] When a spectrum analyzer uses a grating to measure a spectrum, it rotates the grating at angles corresponding to each wavelength from the start to the end of the measurement wavelength range, measuring the spectrum as the light intensity relative to each wavelength. This process of rotating the grating at angles corresponding to each wavelength is also called scanning.

[0005] In the case of measuring the spectrum of pulse light by performing scanning, as Figure 1A and Figure 1B As shown, spectral data is obtained at the timing of emitting pulse light, that is, when the strobe signal synchronized with the pulse light becomes HI, and spectral data is not obtained at the timing of not emitting pulse light, that is, when the strobe signal becomes LO.

[0006] Therefore, to acquire spectral data for all wavelengths within the measurement wavelength range, the phase of the pulse signal is shifted and multiple measurements are performed, thereby acquiring spectral data per pulse period. The smaller the phase shift, or the greater the number of measurements, the greater the overlap width of the waveforms obtained from each measurement. A larger overlap width improves the quality of the measured spectral waveform.

[0007] On the other hand, the more measurements are taken, the longer the spectrum measurement time becomes. In other words, there is a trade-off between the length of the measurement time and the quality of the measured spectrum waveform. It is desirable to ensure the quality of the spectrum waveform while shortening the measurement time to improve user convenience. Summary of the Invention

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a pulse light measurement method, a pulse light measurement program, and a spectrum analyzer that can improve user convenience.

[0009] Several embodiments involve (1) a pulse light measurement method for measuring a spectrum of pulse light. The pulse light measurement method includes the following steps: setting an overlap width of wavelengths for measuring light intensity in a plurality of scans performed within a wavelength range for measuring the spectrum; starting each of the plurality of scans after a delay time specified by the overlap width has elapsed from detection of a trigger of a strobe signal synchronized with the pulse light; and synthesizing and displaying the spectrum based on a plurality of waveforms obtained by performing the plurality of scans.

[0010] The ability to set the wavelength overlap width when performing multiple scans allows both ensuring the quality of the spectral waveform and shortening the measurement time. Consequently, user convenience is improved.

[0011] One embodiment (2) relates to the pulse light measurement method described in (1) above, wherein when synthesizing the spectrum based on the plurality of waveforms, the intensity detected during a period when the waveform data is not defective can be used as the light intensity of the wavelengths superimposed on each other in the plurality of waveforms. This eliminates defects in the synthesized waveform. As a result, the waveform quality is improved.

[0012] One embodiment relates to (3) the pulse light measurement method described in (1) above, wherein the lag time is extended in accordance with the order in which the multiple scans are performed, and when synthesizing the spectrum based on the multiple waveforms, the light intensity of the wavelengths superimposed on each other in the multiple waveforms can be a value obtained by performing a scan performed later. This eliminates the need to store waveforms obtained by scans performed earlier. As a result, the process of synthesizing the waveforms becomes simpler.

[0013] One embodiment involves (4), based on the pulse light measurement method described in (1) above, in a case where the lag time is extended in the order of performing the multiple scans, when the spectrum is synthesized according to the multiple waveforms, the light intensity of the wavelengths superimposed on each other in the multiple waveforms can be the intensity detected during the period when the waveform data does not become defective data, and the intensity detected by the scan performed later.

[0014] One embodiment involves (5), based on the pulse light measurement method described in (1) above, in which, when synthesizing the spectrum based on the plurality of waveforms, a larger value can be used as the light intensity of the wavelengths superimposed on each other in the plurality of waveforms.

[0015] One embodiment involves (6), based on the pulse light measurement method described in (1) above, when the spectrum is synthesized according to the multiple waveforms, a larger value of the intensities detected during the period when the waveform data does not become defective data can be used as the light intensity of the wavelengths superimposed on each other in the multiple waveforms.

[0016] One embodiment (7) relates to the pulse light measurement method according to any one of (1) to (6) above, further comprising the step of setting the overlap width as a ratio to the pulse width of the pulse light. Setting the overlap width as a ratio to the pulse width makes it easier for the user to intuitively understand the overlap width. As a result, user convenience is improved.

[0017] One embodiment (8) is based on the pulse light measurement method described in (7), and further includes the step of determining the number of scans to be performed based on the pulse width and the superposition width. This makes it easier to know the measurement time.

[0018] One embodiment relates to (9), in the pulse light measurement method described in any one of (1) to (8), further comprising the step of displaying the waveforms obtained by each of the plurality of scans in a distinguishable manner. Displaying the waveforms obtained by each scan in a distinguishable manner makes it easier for a user to determine how to set the overlap width. As a result, user convenience is improved.

[0019] One embodiment (10) is the pulse light measurement method according to any one of (1) to (9) above, further comprising the step of accepting input for setting the overlap width during the execution of the multiple scans. Accepting input for setting the overlap width during the execution of the multiple scans allows the user to immediately confirm how the composite waveform changes as a result of the overlap width setting, making it easier to determine how to set the overlap width. Consequently, user convenience is improved.

[0020] One embodiment (11) is the pulse light measurement method according to any one of (1) to (10) above, further comprising the step of accepting input for setting the overlap width while the waveform of the spectrum is displayed. Accepting input for setting the overlap width while the waveform of the spectrum is displayed makes it easier for the user to determine how to set the overlap width. Consequently, user convenience is improved.

[0021] Several embodiments involve (12) a pulse light measurement program that causes a spectrum analyzer for measuring a spectrum of pulse light to perform the following processing: setting an overlapping width of wavelengths for measuring light intensity in multiple scans performed within a measurement wavelength range of the spectrum; starting each of the multiple scans after a lag time specified based on the overlapping width has elapsed since a trigger of a selection signal synchronized with the pulse light is detected; and synthesizing and displaying the spectrum based on multiple waveforms obtained by performing the multiple scans.

[0022] (13) The spectrum analyzer according to some embodiments comprises: a measuring unit for measuring a spectrum of pulsed light; and a light detecting unit for detecting the light intensity of each wavelength of the pulsed light. The measuring unit sets the overlap width of the wavelengths for measuring the light intensity in each of the plurality of scans performed within the wavelength range of the spectrum. The light detecting unit starts each of the plurality of scans after a delay time specified by the overlap width has elapsed since the triggering of the strobe signal synchronized with the pulsed light has been detected. The measuring unit synthesizes the spectrum based on the plurality of waveforms obtained by performing the plurality of scans and displays the synthesized spectrum.

[0023] Effects of the Invention

[0024] According to the pulse light measurement method, pulse light measurement program, and spectrum analyzer according to the present invention, user convenience is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A This is a timing chart of the first scan of the measurement method according to the comparative example.

[0026] Figure 1B is through Figure 1A The waveform of the data measured by scanning.

[0027] Figure 2A This is a timing chart of the second scan of the measurement method according to the comparative example.

[0028] Figure 2B is through Figure 2A The waveform of the data measured by scanning.

[0029] Figure 3 It will Figure 2A The waveform and Figure 2B The waveform obtained by synthesizing the waveforms of .

[0030] Figure 4 This is a block diagram showing a configuration example of a spectrum analyzer according to one embodiment of the present invention.

[0031] Figure 5 This is a flowchart showing an example of the flow of the pulse light measurement method according to the present invention.

[0032] Figure 6A This is a timing chart of the first scan of the measurement method according to the present invention.

[0033] Figure 6B is through Figure 6A The waveform of the data measured by scanning.

[0034] Figure 7A This is a timing chart of the second scan of the measurement method according to the present invention.

[0035] Figure 7B is through Figure 7A The waveform of the data measured by scanning.

[0036] Figure 8A This is a timing chart of the third scan of the measurement method according to the present invention.

[0037] Figure 8B is through Figure 8A The waveform of the data measured by scanning.

[0038] Figure 9A This is a timing chart of the fourth scan of the measurement method according to the present invention.

[0039] Figure 9B is through Figure 9A The waveform of the data measured by scanning.

[0040] Figure 10 It will Figure 6B The waveform, Figure 7B The waveform, Figure 8B The waveform and Figure 9B The waveform obtained by synthesizing the waveforms of .

[0041] Figure 11 This figure shows an example of a setting screen for the waveform superimposition width.

[0042] Figure 12 This is a diagram showing an example of separately displaying data measured by each scan. DETAILED DESCRIPTION

[0043] The present invention relates to a spectrum analyzer for measuring the spectrum of pulsed light. In this invention, a grating method is employed as the measurement method. When measuring the spectrum of pulsed light, a grating-based spectrum analyzer rotates the grating at angles corresponding to each wavelength from the start wavelength to the end wavelength of the measurement wavelength range, and measures the spectrum as the light intensity relative to each wavelength. This operation of rotating the grating at angles corresponding to each wavelength to measure the spectrum is also called scanning.

[0044] When measuring pulsed light, a spectrum analyzer can measure the spectrum of wavelengths corresponding to the period when the pulsed light is on, but cannot measure the spectrum of wavelengths corresponding to the period when the pulsed light is off. Here, the period of performing a single scan includes both the period when the pulsed light is on and the period when the pulsed light is off. To measure the light intensity of all wavelengths within the wavelength measurement range, multiple scans are required.

[0045] When measuring pulsed light, the spectrum analyzer performs multiple scans across all wavelengths in the measurement wavelength range, shifting the phase of a signal synchronized with the pulsed light so that the pulsed light is on for at least one scan. The phase shift during each scan is controlled by delaying the start of each scan relative to the timing of the trigger detection of the signal synchronized with the pulsed light. The spectrum analyzer synthesizes the measurement data obtained from each scan to measure a spectrum across the entire measurement wavelength range.

[0046] The spectrum analyzer shifts the phase of each scan according to the duty cycle of the pulsed light, so that the pulsed light is on for at least one scan across all wavelengths in the measurement wavelength range. The amount of phase shift during each scan affects the spectrum measurement results.

[0047] Specifically, the smaller the phase offset between scans, the greater the overlap width of wavelengths over which intensities can be obtained in each scan. The greater the overlap width, the higher the quality of the measured spectral waveform. On the other hand, reducing the phase offset increases the number of measurements required to generate the pulsed light on period for all wavelengths in the measurement wavelength range. The greater the number of measurements, the longer the spectral measurement time. In other words, there is a trade-off between the length of the measurement time and the quality of the measured spectral waveform. It is necessary to strike a balance between the spectral measurement time and the quality of the measured waveform.

[0048] Therefore, according to the present invention, a spectrum analyzer sets the wavelength overlap width required to obtain the intensity during each scan. Users can set this wavelength overlap width while observing the measured waveform. This results in a balanced balance between spectrum measurement time and the quality of the measured waveform.

[0049] Hereinafter, embodiments of the present invention will be described in comparison with comparative examples.

[0050] (Comparative Example)

[0051] In the comparative example, the duty cycle of the pulse light to be measured by the spectrum analyzer was set to 50%, and the intensity of each wavelength of the pulse light was set to be the same.

[0052] The spectrum analyzer starts scanning with the strobe signal synchronized with the pulse light as the trigger. Figure 1A As shown in the timing diagram, the strobe signal is represented by two signal levels: HI and LO. The strobe signal level is set to HI in synchronization with the period when the pulse light is on. The strobe signal level is set to LO in synchronization with the period when the pulse light is off.

[0053] exist Figure 1A In Figure 1, the spectrum analyzer uses the rising edge of the strobe signal as a trigger to initiate the first sweep. The rising edge of the strobe signal indicates a transition from LOW to HI. During the spectrum analyzer's sweep, the sweep signal level is represented by HI. The time required to move the grating so that the spectrum analyzer covers the entire measurement wavelength range is represented by T_E.

[0054] By Figure 1A The scanning operation is performed at the timing shown in the timing diagram, and the spectrum of the pulse light in the measurement wavelength range is obtained. Figure 1B The waveform shown. Figure 1B The time when the scanning operation starts is represented on the horizontal axis as 0. When the duty ratio of the pulse light is 50%, the intensity of the spectrum is obtained in a range of 50% of the measurement wavelength range.

[0055] In the comparative example, Figure 2A As shown in FIG, the spectrum analyzer starts the second scanning action at a time lag of T_D relative to the time 0 when the strobe signal rises. T_D is also called the lag time. Figure 2A In FIG. 1 , the delay time T_D is set to 100% of the pulse width of the pulse light, that is, the time period of 100% of the pulse width of the gate signal. The pulse width indicates the length of the period during which the pulse light is on.

[0056] By Figure 2A The scanning operation is performed at the timing shown in the timing diagram, and the spectrum of the pulse light in the measurement wavelength range is obtained. Figure 2B The waveform shown. Figure 2B The horizontal axis of the time when the scanning action starts is represented as 0. By setting the delay time T_D to 100% of the pulse width, Figure 2B The range of intensities in which the spectra were obtained complements the Figure 1B The range of the intensity of the spectrum obtained. Figure 1B The wavelengths for which no intensity was obtained in Figure 2B Get the strength.

[0057] Through Figure 1B The waveform obtained by the first scanning action shown in the figure and the Figure 2B The waveform obtained by the second scanning action shown in FIG is synthesized, so that Figure 3 The waveform of the spectrum of the generated pulse light is shown.

[0058] Here, Figure 1B and Figure 2B The waveform of the pulse light spectrum shown has a defect in the initial wavelength of the pulse light rise. The defect is a state where the measurement result is smaller than the light intensity that should be measured. Figure 1B The range of intensity obtained in the waveform is Figure 2B The waveform of does not correspond to the range of intensities. Figure 1B The range of the waveform where the intensity is not obtained is the same as Figure 2B Therefore, the range of the intensity obtained in the waveform of Figure 1B and Figure 2B The waveform is synthesized. As a result, Figure 3 The waveform shown remains defective.

[0059] Remaining defects in the spectral waveform degrade the quality of the spectral waveform. Here, if a defect exists in a waveform, the defect can be compensated by detecting the intensity of the defective area through different scans. Specifically, multiple scans can be performed to adjust the lag time so that no defect remains in the waveform.

[0060] In the comparative example, considering Figure 1B and Figure 2B The lag time is determined based on the defect shown. However, the length of time from the rising edge of the pulse light to the generation of the defect sometimes varies. Considering the margin when determining the lag time, it is possible to set the lag time to a longer value. However, the longer the lag time, the longer the measurement time. It is necessary to achieve both maintaining the quality of the spectral waveform and shortening the measurement time.

[0061] Next, in the present invention, a pulse light measurement method, a pulse light measurement program, and a spectrum analyzer 10 (see FIG. 1 ) capable of adjusting the balance between the measurement time of a spectrum and the quality of the measured waveform are described. Figure 4 ) for explanation.

[0062] (Configuration Example of Spectrum Analyzer 10)

[0063] like Figure 4 As shown, a spectrum analyzer 10 according to an embodiment of the present invention includes a light input unit 11 , a light detection unit 12 , a measurement unit 13 , a display unit 14 , and an operation unit 15 .

[0064] The light input unit 11 includes an input port. The input port is configured to be able to input pulse light to be measured by the optical spectrum analyzer 10.

[0065] The light detection unit 12 is constructed by including a spectrometer and a light-receiving element. The spectrometer separates the pulsed light into light of different wavelengths, allowing light of the detection wavelength to pass through. In the present invention, a grating is used as the spectrometer. The light detection unit 12 moves the grating in accordance with control instructions from the measurement unit 13, performing a scan and detecting the light intensity of each wavelength within the measurement wavelength range.

[0066] The measuring unit 13 controls the timing of starting the scanning operation of the light detecting unit 12, and causes the light detecting unit 12 to perform multiple scanning operations. The measuring unit 13 obtains the detection results of each scan from the light detecting unit 12, and synthesizes the waveforms of the detection results to generate the waveform of the spectrum of the pulsed light.

[0067] The measuring unit 13 may include, for example, a processor such as a CPU (Central Processing Unit). The measuring unit 13 may implement predetermined functions by causing the processor to execute a predetermined program. The measuring unit 13 may include, for example, a dedicated circuit such as an FPGA (Field Programmable Gate Array).

[0068] The measurement unit 13 may include a storage unit. The storage unit stores various information used for the operation of the spectrum analyzer 10, or programs used to implement the functions of the spectrum analyzer 10. The storage unit can function as working memory for the measurement unit 13. The storage unit can be composed of, for example, a semiconductor memory. The storage unit can be configured to include volatile memory or nonvolatile memory. At least a portion of the storage unit can be configured as a storage device connected to the outside of the spectrum analyzer 10.

[0069] The measuring unit 13 can be realized as a computer such as a desktop PC (Personal Computer) or a notebook PC connected to the outside of the spectrum analyzer 10 .

[0070] The display unit 14 can be configured to include various displays such as a liquid crystal display. The display unit 14 can be configured as a touch panel display that displays a GUI (Graphical User Interface) functioning as the operation unit 15 and receives input from the user. In other words, the display unit 14 and the operation unit 15 can be integrally formed.

[0071] The operating unit 15 may include an input device for receiving user input. For example, the input device may include a keyboard or physical keys, or may include a touch panel, touch sensor, or pointing device such as a mouse. As described above, the operating unit 15 may be configured as a touch panel display integrated with the display unit 14. The operating unit 15 is also referred to as the input unit.

[0072] (Operation Example of Spectrum Analyzer 10)

[0073] The spectrum analyzer 10 generates a waveform of the spectrum of pulsed light. By performing a single scan, the spectrum analyzer 10 can acquire waveforms of the spectrum of a portion of the wavelengths within the entire measurement wavelength range of the pulsed light. The spectrum analyzer 10 synthesizes waveforms acquired through multiple scans to generate waveforms of the spectrum of the entire measurement wavelength range of the pulsed light. The waveform synthesized from the waveforms acquired through multiple scans is also referred to as a synthesized waveform.

[0074] Here, the waveform acquired in a single scan is the waveform at the wavelength corresponding to the period during which the pulsed light is on. At the beginning of the pulsed light period, the waveform experiences defects during the initial rise time. These defects degrade the waveform quality of the pulsed light spectrum. The wavelength range in which the waveform exhibits defects is also referred to as the defect range.

[0075] A missing range in a waveform acquired through a single scan is compensated for by acquiring waveforms in the same wavelength range in other scans without missing any. The spectrum analyzer 10 according to the present invention is configured to set the wavelength overlap width of waveforms acquired through multiple scans, so that waveforms acquired through other scans can compensate for the missing range. This ability to set the wavelength overlap width allows the user to observe the measured waveform and set the wavelength overlap width accordingly. This results in a balanced balance between spectrum measurement time and the quality of the measured waveform.

[0076] Next, a specific operation example of the optical spectrum analyzer 10 according to the present invention will be described.

[0077] The spectrum analyzer 10 may perform operations including Figure 5 The pulse light measurement method includes the flow chart shown as an example. The pulse light measurement method can be implemented as a pulse light measurement program executed by the spectrum analyzer 10. The pulse light measurement program can be stored in a non-transitory computer-readable medium.

[0078] The measuring unit 13 sets the superposition width (step S1). The superposition width is expressed as a ratio relative to the length of the pulse width of the pulse light. In the present invention, the superposition width is set to Y%. Y is set to a value greater than 0% and less than 100%. In the present invention, Y is set to 50%. In addition, the duty cycle of the pulse light is represented by X%, which is set to 50% in the present invention. In this case, the superposition width corresponds to a length of 25% of the pulse period. As described later, the measuring unit 13 can set the superposition width based on a setting input from the user. By setting the superposition width as a ratio relative to the pulse width, the user can easily understand the superposition width by feeling. As a result, the convenience of the user is improved.

[0079] The measuring unit 13 sets a lag time for the light detection unit 12 (step S2). The lag time is the time by which the start timing of each scan is delayed relative to the rising edge of the strobe signal synchronized with the pulsed light when the light detection unit 12 performs multiple scans. By sequentially extending the lag time when performing multiple scans, the measuring unit 13 can overlap the wavelengths of the waveforms obtained by each scan so that the waveforms obtained by the subsequent scans complement the missing range of the waveform obtained by the first scan. The measuring unit 13 sets the lag time to zero when performing the first scan.

[0080] The light detecting section 12 determines whether a strobe signal trigger is detected (step S3). The strobe signal trigger is a trigger generated by a change in the signal level of the strobe signal. In the present invention, the strobe signal trigger is generated when the strobe signal rises.

[0081] like Figure 6A In this example, it is assumed that the strobe signal trigger is generated when the signal level of the strobe signal changes from LO to HI in the first scan. The time when the strobe signal trigger is generated is represented by 0.

[0082] When the strobe signal trigger is not detected (step S3 : NO), the light detection unit 12 repeatedly executes the determination flow of step S3 until the strobe signal trigger is detected.

[0083] When the strobe trigger is detected (step S3: YES), the light detecting unit 12 determines whether the delay time has elapsed since the strobe trigger was detected (step S4). If the delay time is set to zero, the light detecting unit 12 determines that the delay time has elapsed when the strobe trigger is detected.

[0084] When the delay time has not elapsed (step S4 : NO), the light detection unit 12 repeatedly executes the determination flow of step S4 until the delay time elapses.

[0085] If the delay time has passed (step S4: YES), the light detection unit 12 starts scanning (step S5). As described above, the delay time of the first scan is set to zero. Figure 6A As shown in the example, the light detection unit 12 starts the first scanning operation from the time 0 when the strobe signal trigger is generated. The period during which the scanning operation is performed is represented by a state in which the signal level of the scanning operation is HI.

[0086] The light detection unit 12 determines whether the scanning time has elapsed (step S6). The scanning time is the time required to move the grating so that the intensity of all wavelengths in the measurement wavelength range can be measured. The scanning time is represented by T_E. If the scanning time has not elapsed (step S6: NO), the light detection unit 12 repeatedly executes the determination process of step S6 until the scanning time has elapsed, continuously scanning the entire measurement wavelength range.

[0087] If the scanning time has elapsed (step S6: YES), the light detection unit 12 ends one scanning operation. Figure 6B For example, the light detection unit 12 can detect a waveform measured in a wavelength range corresponding to a period during which the pulse light is on.

[0088] exist Figure 6B In the figure, the horizontal axis represents time. This time corresponds to each wavelength in the measurement wavelength range. Time 0 corresponds to the minimum wavelength in the measurement wavelength range. Time T_E corresponds to the maximum wavelength in the measurement wavelength range. The vertical axis represents the light intensity at each wavelength, with the maximum value being 1.

[0089] The light detection unit 12 outputs the detected waveform to the measurement unit 13 .

[0090] After the light detection unit 12 completes one scan, the measurement unit 13 determines whether data acquisition for the measurement wavelength range has been completed (step S7). The measurement unit 13 acquires the waveform detected by the one scan from the light detection unit 12. If waveforms can be acquired for all wavelengths in the measurement wavelength range, the measurement unit 13 determines that data acquisition for the measurement wavelength range has been completed.

[0091] At the time the first scan operation ends, the measurement unit 13 is only able to acquire waveforms for a portion of the wavelengths within the measurement wavelength range. Therefore, the measurement unit 13 determines that data acquisition for the measurement wavelength range has not yet been completed. If data acquisition for the measurement wavelength range has not yet been completed (step S7: NO), the measurement unit 13 updates the delay time set for the light detection unit 12 to perform the next scan (step S8).

[0092] As described above, the measuring unit 13 sequentially extends the lag time when performing multiple scans. That is, the measuring unit 13 sets the lag time when performing the next scan as the time extended relative to the lag time set when performing the previous scan. In the case where the superposition width of the pulse light is represented by Y%, the time extended relative to the lag time is calculated as the value obtained by multiplying the length of the pulse width of the pulse light by (1-Y / 100). In addition, in the case where the duty cycle of the pulse light is represented by X%, the length of the pulse width is calculated as the value obtained by multiplying the length of the pulse period by (X / 100). Therefore, the time extended relative to the lag time is calculated as the value obtained by multiplying the length of the pulse period of the pulse light by (X / 100)×(1-Y / 100). For example, when the pulse period of the pulse light is 0.1 second, the duty cycle (X) of the pulse light is 25%, and the overlapping width (Y) is 10%, the time extended relative to the delay time calculated by calculating 0.1×(25 / 100)×(1-10 / 100) is 0.0225 seconds.

[0093] In the present invention, the duty cycle (X) of the pulsed light is set to 50%. In addition, as described above, the overlap width (Y) is set to 50%. The measuring unit 13 updates the lag time by multiplying the length of the pulse width of the pulsed light by 50% of the overlap width setting to extend the time. In this case, the lag time is equivalent to 25% of the pulse period, that is, 1 / 4 of the length. The updated lag time is represented by T_D1. After the measuring unit 13 updates the lag time, the process returns to step S3, and the light detection unit 12 performs the second scanning action as the next scan.

[0094] If the light detection unit 12 determines that the strobe signal trigger is detected in the process of step S3 and determines that the delay time T_D1 has passed in the process of step S4, the light detection unit 12 detects that the strobe signal trigger is detected in the process of step S5. Figure 7A As shown in the example, the second scanning operation starts at time T_D1. The period during which the scanning operation is executed is represented by the state where the signal level of the scanning operation is HI. In the process of step S6, the light detection unit 12 continues the second scanning operation until time T_E+T_D1, and then ends.

[0095] The light detection unit 12 can detect the Figure 7B Waveforms shown as examples. Figure 7B The time on the horizontal axis is Figure 6B The relationship between the measurement wavelength range and the time is consistent, as Figure 7A The time obtained by subtracting T_D1 from the time of . That is, the time when the scan starts is represented by 0. The time when the scan ends is represented by T_E. Figure 7BThe time 0 on the horizontal axis corresponds to the minimum wavelength in the measurement wavelength range. The time T_E corresponds to the maximum wavelength in the measurement wavelength range. The vertical axis represents the light intensity of each wavelength, with the maximum value being 1.

[0096] exist Figure 7B The waveform and Figure 6B In the comparison of the waveforms, according to Figure 7B The wavelength range of the waveform detected is 1 / 4 of the pulse period, that is, the phase is 90 degrees, compared with the Figure 6B The wavelength range detected by the waveform is shifted to the shorter wavelength side. Figure 6B The waveform and Figure 7B Therefore, the measuring unit 13 determines that the acquisition of data in the measurement wavelength range is not completed, and updates the lag time set for the light detection unit 12 in the process of step S8.

[0097] As the delay time for the third scan operation, the measurement unit 13 updates the delay time by extending it by the time obtained by multiplying the pulse width of the pulsed light by 50% of the overlap width, compared to the delay time for the second scan operation. The updated delay time is represented by T_D2. After the measurement unit 13 updates the delay time, the process returns to step S3, and the light detection unit 12 performs the third scan operation as the next scan.

[0098] If the light detection unit 12 determines that the strobe signal trigger is detected in the process of step S3 and determines that the delay time T_D2 has passed in the process of step S4, the light detection unit 12 detects that the strobe signal trigger is detected in the process of step S5. Figure 8A As shown in the example, the third scanning operation starts at time T_D2. The period during which the scanning operation is executed is represented by the state where the signal level of the scanning operation is HI. In the process of step S6, the light detection unit 12 continues the third scanning operation until time T_E+T_D2, and then ends.

[0099] The light detection unit 12 can detect the Figure 8B Waveforms shown as examples. Figure 8B The time on the horizontal axis is Figure 6B and Figure 7B The relationship between the measurement wavelength range and the time is consistent, as Figure 8A The time obtained by subtracting T_D2 from the time of . That is, the time when the scan starts is represented by 0. The time when the scan ends is represented by T_E. Figure 8B The time 0 on the horizontal axis corresponds to the minimum wavelength in the measurement wavelength range. The time T_E corresponds to the maximum wavelength in the measurement wavelength range. The vertical axis represents the light intensity of each wavelength, with the maximum value being 1.

[0100] exist Figure 8B The waveform and Figure 7B In the comparison of the waveforms, according to Figure 8B The wavelength range of the waveform detected is 1 / 4 of the pulse period, that is, the phase is 90 degrees, compared with the Figure 7B The wavelength range detected by the waveform is shifted to the shorter wavelength side. Figure 6B The waveform, Figure 7B The waveform and Figure 8B When the waveforms of are synthesized, waveforms are obtained for all wavelengths in the measurement wavelength range. Figure 8B The defect range of the waveform does not match Figure 6B and Figure 7B Therefore, the measuring unit 13 determines that the acquisition of data in the measurement wavelength range is not completed, and in the process of step S8, updates the delay time set for the light detection unit 12.

[0101] As the delay time for the fourth scanning operation, the measuring unit 13 updates the delay time by extending it by a time equal to the pulse width of the pulsed light multiplied by 50% of the overlap width set as the overlap width, compared to the delay time for the third scanning operation. The updated delay time is represented by T_D3. After the measuring unit 13 updates the delay time, the process returns to step S3, and the light detection unit 12 performs the fourth scanning operation as the next scan.

[0102] If the light detection unit 12 determines that the strobe signal trigger is detected in the process of step S3 and determines that the delay time T_D3 has passed in the process of step S4, the light detection unit 12 detects that the strobe signal trigger is detected in the process of step S5. Figure 9A As shown in the example, the fourth scanning operation starts at time T_D3. The period during which the scanning operation is executed is represented by the state where the signal level of the scanning operation is HI. In the process of step S6, the light detection unit 12 continues the fourth scanning operation until time T_E+T_D3, and then ends.

[0103] The light detection unit 12 can detect the Figure 9B Waveforms shown as examples. Figure 9B The time on the horizontal axis is Figure 6B 、 Figure 7B and Figure 8B The relationship between the measurement wavelength range and the time is consistent, as Figure 9A The time obtained by subtracting T_D3 from the time of . That is, the time when the scan starts is represented by 0. The time when the scan ends is represented by T_E. Figure 9BThe time 0 on the horizontal axis corresponds to the minimum wavelength in the measurement wavelength range. The time T_E corresponds to the maximum wavelength in the measurement wavelength range. The vertical axis represents the light intensity of each wavelength, with the maximum value being 1.

[0104] exist Figure 9B The waveform and Figure 8B In the comparison of the waveforms, according to Figure 9B The wavelength range of the waveform detected is 1 / 4 of the pulse period, that is, the phase is 90 degrees, compared with the Figure 8B The wavelength range detected by the waveform is shifted to the shorter wavelength side. Figure 6B The waveform, Figure 7B The waveform, Figure 8B The waveform and Figure 9B When the waveforms of are synthesized, waveforms are obtained for all wavelengths in the measurement wavelength range. Figure 6B 、 Figure 7B 、 Figure 8B and Figure 9B The missing range of each waveform overlaps with the wavelength range of at least one other waveform. Therefore, the measuring unit 13 determines that acquisition of data in the measurement wavelength range has been completed.

[0105] When acquisition of data in the measurement wavelength range is complete (step S7: YES), the measuring unit 13 synthesizes the waveform data acquired by each scan and displays it on the display unit 14 (step S9). The measuring unit 13 can synthesize the waveforms based on the following rules (1) and (2).

[0106] (1) The intensity of the wavelength detected by only one scan is directly used in the composite waveform.

[0107] (2) As the light intensity of the wavelengths superimposed on each other in the waveform detected by two or more scans, the composite waveform uses the intensity detected by each scan during the period when the waveform data does not become missing data. The period when the waveform data does not become missing data is the period after the predetermined time has passed since the gate signal was turned on, during the period when the gate signal was turned on. Conversely, the period when the waveform data becomes missing data is the period within the predetermined time since the gate signal was turned on, during the period when the gate signal was turned on.

[0108] The measuring unit 13 can store at least one of the periods during which the waveform data does not become missing data or the periods during which the waveform data becomes missing data used in (2) above in association with the waveform data in advance when performing each scan, and refer to it when synthesizing the waveform data.

[0109] The measurement unit 13 can appropriately set a predetermined time period for determining whether waveform data has not become missing data or has become missing data. The measurement unit 13 can accept user input for setting the predetermined time period and set the user-entered value as the predetermined time period. The measurement unit 13 can analyze the waveform of the detected intensity of a test signal whose intensity changes stepwise from LO to HI and set the predetermined time period based on the length of the period from when the test signal intensity changes to HI until the waveform intensity stabilizes.

[0110] This eliminates defects in the synthesized waveform, resulting in improved waveform quality.

[0111] In addition, when the lag time is extended in the order of executing a plurality of scans, the measuring unit 13 may synthesize the waveforms based on the rule shown as the following (3) instead of the above (2).

[0112] (3) As the light intensity of the wavelengths superimposed on each other in waveforms detected by two or more scans, the intensity detected by the subsequent scan is used in the composite waveform, regardless of whether the waveform data is missing data. In other words, the intensity detected by the subsequent scan overwrites the intensity of the composite waveform.

[0113] The waveforms acquired by the previous scan can be overwritten with the intensity detected by the subsequent scan, without being stored. This simplifies the process of synthesizing waveforms and reduces the memory capacity required to store the waveforms.

[0114] The measuring unit 13 may synthesize the waveforms based on the rule represented by the following (4) which is a combination of the above (2) and (3), instead of the above (2) or (3).

[0115] (4) As the light intensity of wavelengths superimposed on each other in the waveform detected by two or more scans, the intensity detected by the subsequent scan is used in the composite waveform among the intensities detected during the period when the waveform data does not become defective data.

[0116] The measuring unit 13 may synthesize the waveforms based on the rule shown as the following (5) instead of the above (2) to (4).

[0117] (5) As the light intensity of the wavelengths superimposed on each other in the waveform detected by two or more scans, the larger value of the intensity detected by each scan is used in the composite waveform regardless of whether the waveform data becomes defective data.

[0118] This eliminates defects in the synthesized waveform, resulting in improved waveform quality.

[0119] The measuring unit 13 may synthesize the waveforms based on the rule represented by the following (6) which is a combination of the above (2) and (5), instead of the above (2) to (5).

[0120] (6) As the light intensity of the wavelengths superimposed on each other in the waveforms detected by two or more scans, the larger value among the intensities detected during the period when the waveform data does not become defective data is adopted in the composite waveform.

[0121] like Figure 10 As an example, the measuring unit 13 displays the synthesized waveform of the spectrum of the pulsed light on the display unit 14. In the synthesized waveform, a defect remains on the shortest wavelength side in the measurement wavelength range, but the defect is eliminated in other ranges.

[0122] Defects on the shortest wavelength side of the measurement wavelength range correspond to the rising edge of a pulse in each scan, making them difficult to eliminate. In the spectrum analyzer 10, the grating of the light detection unit 12 can be configured to shift from a wavelength shorter than the minimum value of the measurement wavelength range. By starting the scan at a wavelength shorter than the minimum value of the measurement wavelength range, defects on the shortest wavelength side of the measurement wavelength range can be eliminated.

[0123] In the above-described operation example, data acquisition within the measurement wavelength range is completed by executing four scans. The number of scans required to complete data acquisition within the measurement wavelength range is calculated as a natural number obtained by rounding off the decimal point of the value calculated as 100 / {X×(1-Y / 100)}. For example, if the duty cycle (X) of the pulse light is 25% and the overlap width (Y) is 50%, the number of scans is calculated as 8 by calculating 100 / {25×(1-50 / 100)}.

[0124] In addition, when the wavelengths of the waveforms obtained by each scan are not superimposed at all, that is, when the superposition width (Y) is 0%, the required number of scans is calculated by calculating 100 / X. When the calculation result of the required number of scans produces a decimal point, the digits after the decimal point are rounded off. For example, when the duty cycle of the pulse light is 25%, the required number of scans is calculated to be 4 times by calculating 100 / 25. For example, when the duty cycle of the pulse light is 30%, the required number of scans is calculated to be 4 times by calculating 100 / 30 and rounding off the digits after the decimal point. On the other hand, as described later, the larger the superposition width, the greater the required number of scans.

[0125] After the measurement unit 13 executes the process of step S9, the Figure 5 The measuring unit 13 may also start again after executing the process of step S9. Figure 5 In this case, the user can observe the process of the flowchart as the last Figure 5 The result of the operation of the flowchart is displayed as a result of the composite waveform, and the superposition width is set in the process of step S1. If a defect is observed in the composite waveform, the user can Figure 5 When performing the flowchart of the operation, set the overlap width to a larger value so that the defect disappears. On the contrary, if the defect is not observed in the synthesized waveform, the user can Figure 5 When performing the flow chart operation, set the overlay width to a smaller value to shorten the measurement time.

[0126] To enable the user to set the overlay width, such as Figure 11 For example, the spectrum analyzer 10 can display a setting window 143 on the display unit 14 as a GUI for setting the overlay width. Setting window 143 can be displayed when a touch or click operation is input to the setting unit 142 that displays the set value of the overlay width. Setting window 143 can be displayed above the waveform display unit 141 that displays the waveform, or it can be displayed outside of the waveform display unit 141. Setting window 143 can be configured to accept input of a value set for Y% representing the overlay width. For example, setting window 143 can be configured to accept input of a value from 1% to 99%.

[0127] The spectrum analyzer 10 can accept input from the user for setting the superposition width in the setting window 143 while the synthesized waveform is displayed on the waveform display unit 141. Accepting input for setting the superposition width while the synthesized waveform is displayed makes it easier for the user to determine how to set the superposition width. Consequently, user convenience is improved.

[0128] The spectrum analyzer 10 can accept input from the user for setting the overlap width in the settings window 143 while executing multiple scans. Accepting input for setting the overlap width during multiple scans allows the user to immediately confirm how the overlap width setting has been changed, making it easier for the user to determine how to set the overlap width. Consequently, user convenience is improved.

[0129] The setting window 143 can be configured to allow input of a setting indicated as AUTO. When the overlap width is set to AUTO, the measuring unit 13 automatically sets the overlap width. For example, the measuring unit 13 can set the overlap width to 5%. The measuring unit 13 can analyze the defect range of the waveforms acquired in each scan and automatically set the overlap width so that the defect is eliminated in the synthesized waveform.

[0130] Before the acquisition of data in the measurement wavelength range is completed, the measuring unit 13 may sequentially synthesize the waveforms acquired in each scan as part of the measurement process and display the synthesized waveforms on the display unit 14 .

[0131] like Figure 12 For example, the measurement unit 13 may display the waveforms obtained by each scan on the display unit 14 in a manner that allows the waveforms to be distinguished from each other. Figure 12 In the example, the waveforms obtained by each of the three scans are displayed with different line types. Alternatively, the waveforms obtained by each scan can be displayed using line colors to differentiate them. The waveforms obtained by each scan are not limited to line types or colors; other display methods are possible. By displaying the waveforms obtained by each scan in a distinguishable manner, the user can easily determine how to set the overlay width. This improves user convenience.

[0132] The measuring unit 13 sequentially increases the delay time as the number of scans increases, but may also shorten the delay time during repeated scans. Furthermore, the measuring unit 13 sets the delay time so that the difference in delay time between scans is equal, but may also set the delay time so that the difference in delay time between scans is different.

[0133] The measuring unit 13 can determine the number of scans to be performed based on the pulse width and the overlap width. The measurement unit 13 can easily determine the measurement time by determining the number of scans to be performed. The measuring unit 13 can set the delay time so that the difference in delay time between scans is equal, depending on the determined number of scans.

[0134] (Summarize)

[0135] As described above, the spectrum analyzer 10 according to the present invention sets the overlap width of the waveforms obtained from each scan when performing multiple scans, and varies the timing of starting each scan. This allows the waveforms of the pulsed light spectrum to be detected in different wavelength ranges in each scan. The spectrum analyzer 10 synthesizes the waveforms detected from each scan to generate the waveform of the pulsed light spectrum, eliminating waveform defects that occur at the initial rising edge of the pulsed light. Furthermore, the spectrum analyzer 10 is configured so that the user can set the overlap width while observing the waveform of the spectrum. This results in a balanced balance between the measurement time of the spectrum and the quality of the measured waveform. This also improves user convenience.

[0136] In the above-described embodiment, the overlap width is expressed as a ratio relative to the pulse width of the pulse light, but it may be expressed in various other forms such as a ratio relative to the pulse period of the pulse light.

[0137] While the embodiments of the present invention have been described with reference to the accompanying drawings and examples, it should be noted that those skilled in the art are capable of various modifications and variations based on the present invention. Therefore, it should be noted that such modifications and variations are within the scope of the present invention. For example, the functions of each component can be rearranged in a theoretically consistent manner, and multiple components can be combined into a single component or divided.

[0138] Description of the label

[0139] 10. Spectrum Analyzer

[0140] 11 Optical input unit

[0141] 12 Light detection unit

[0142] 13 Measurement Department

[0143] 14 Display unit (141: waveform display unit, 142: setting unit, 143: setting window)

[0144] 15 Operation Department

Claims

1. A pulse light measurement method, which measures the spectrum of pulse light, wherein: The pulse light measurement method comprises the following steps: setting the overlapping width of the wavelengths for measuring the light intensity in each of the plurality of scans performed in the measurement wavelength range of the spectrum; starting each of the plurality of scans after a delay time defined by the overlap width has elapsed since a trigger of a gate signal synchronized with the pulse light is detected; as well as The spectrum is synthesized and displayed based on a plurality of waveforms obtained by performing the plurality of scans.

2. The pulse light measurement method according to claim 1, wherein: When synthesizing the spectrum based on the plurality of waveforms, the intensity detected during a period in which the data of the waveforms does not become defective data is used as the light intensity of the wavelengths superimposed on each other in the plurality of waveforms.

3. The pulse light measurement method according to claim 1, wherein When the lag time is extended in the order in which the plurality of scans are performed, when synthesizing the spectrum based on the plurality of waveforms, the intensity detected by the scan performed later is used as the light intensity of the wavelengths superimposed on each other in the plurality of waveforms.

4. The pulse light measurement method according to claim 1, wherein In the case where the lag time is extended in the order of performing the multiple scans, when the spectrum is synthesized based on the multiple waveforms, the intensity detected by the scan performed later is used as the light intensity of the wavelengths superimposed on each other in the multiple waveforms, among the intensities detected during the period when the data of the waveform does not become defective data.

5. The pulse light measurement method according to claim 1, wherein When the spectrum is synthesized based on the plurality of waveforms, a larger value is adopted as the light intensity of wavelengths superimposed on each other in the plurality of waveforms.

6. The pulse light measurement method according to claim 1, wherein When synthesizing the spectrum based on the plurality of waveforms, a larger value among the intensities detected during a period in which the waveform data does not become defective data is adopted as the light intensity of the wavelengths superimposed on each other in the plurality of waveforms.

7. The pulse light measurement method according to any one of claims 1 to 6, wherein The pulse light measurement method further includes setting the superposition width as a ratio to a pulse width of the pulse light.

8. The pulse light measurement method according to claim 7, wherein: The pulse light measurement method further includes determining the number of times the scan is performed based on the pulse width and the overlap width.

9. The pulse light measurement method according to any one of claims 1 to 6, wherein The pulse light measurement method further includes displaying the waveforms obtained through the plurality of scans in a distinguishable manner.

10. The pulse light measurement method according to any one of claims 1 to 6, wherein The pulse light measurement method further includes the step of accepting an input of a setting of the overlap width during execution of the plurality of scans.

11. The pulse light measurement method according to any one of claims 1 to 6, wherein The pulse photometry method further includes the step of accepting an input of a setting of the superposition width while the waveform of the spectrum is displayed.

12. A pulsed light measurement program, wherein: The spectrum analyzer that measures the spectrum of the pulsed light is caused to perform the following processing: setting the overlapping width of the wavelengths for measuring the light intensity in each of the plurality of scans performed in the measurement wavelength range of the spectrum; starting each of the plurality of scans after a delay time defined by the overlap width has elapsed since a trigger of a gate signal synchronized with the pulse light is detected; as well as The spectrum is synthesized and displayed based on a plurality of waveforms obtained by performing the plurality of scans.

13. A spectrum analyzer, wherein: The spectrum analyzer includes: a measuring unit that measures the spectrum of the pulse light; and a light detecting unit that detects the light intensity of each wavelength of the pulse light. The measuring unit sets the overlapping width of the wavelengths for measuring the light intensity in each of the plurality of scans performed in the measurement wavelength range of the spectrum. The light detection unit starts each of the plurality of scans after a delay time defined by the overlap width has elapsed since the trigger of the strobe signal synchronized with the pulse light is detected. The measuring unit synthesizes and displays the spectrum based on a plurality of waveforms obtained by performing the plurality of scans.

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