JP2023106196A - Optical pulse meter, optical pulse measuring method, and optical pulse measuring program - Google Patents

Abstract

To provide an optical pulse meter which can reduce a measurement time.SOLUTION: An optical pulse meter 100 comprises: a wavelength variable filter 13 capable of successively changing the transmission wavelength band of first light to be measured that is branched from light to be measured; an optical detector array 14 made by arranging, in array form along a region, a plurality of optical detectors to which first light to be measured having passed through the wavelength variable filter 13 and second light to be measured having been branched from the light to be measured and not having passed through the wavelength variable filter enter, and which output a photocurrent obtained based on exponential strength of light at a plurality of positions in a region where the first light to be measured and the second light to be measured optically overlap; a generation unit 501 for generating a spectrogram on the basis of a photocurrent that corresponds to the transmission wavelength band set by the wavelength variable filter 13 and the position of the region; and an identification unit 502 for identifying the amplitude and phase of the light to be measured, on the basis of the spectrogram generated by the generation unit 501.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical pulse measuring instrument, an optical pulse measuring method, and an optical pulse measuring program.

In the field of optical communication or optical measurement, high-speed optical pulse signals are handled, and the pulse width of optical pulses reaches 100 ps or less, and high-speed ones reach 10 ps or less. Demands for measuring optical pulses of 10 ps or less are increasing with the speeding up of optical communication or optical measurement. Patent Literature 1 discloses a technique related to an optical correlator that increases the operation speed of optical correlation measurement and enables waveform measurement of a single optical pulse.

If the amplitude shape (envelope) and phase of a high-speed, short-period optical pulse signal can be measured, the shape of the carrier wave can be grasped, and detailed time characteristics of the optical pulse signal can be clarified. When measuring the amplitude shape and phase of an optical pulse signal, an optical pulse signal obtained by transmitting a predetermined wavelength band of the optical pulse signal to be measured, and an optical pulse obtained by delaying the optical pulse signal to be measured by a predetermined time. A method of analyzing the characteristics of a signal synthesized with a signal is adopted.

JP 2017-32306 A

The present invention has been made in view of the above points. An object of the present invention is to provide an optical pulse measuring instrument, an optical pulse measuring method, and an optical pulse measuring program capable of shortening the measurement time compared to the case of synthesizing time-delayed optical pulse signals.

A first aspect of the present invention is an optical pulse measuring instrument, comprising: a tunable filter capable of continuously changing a transmission wavelength band of a first light to be measured branched from a light to be measured; The first light under measurement and the second light under measurement branched from the light under measurement and not passing through the wavelength tunable filter are entered, and the first light under measurement and the second light under measurement are a photodetector comprising a plurality of photodetectors arranged in an array along the optically overlapping region for outputting photocurrents obtained based on power-law intensities of light at a plurality of positions in the region; a generator for generating a spectrogram based on the photocurrent corresponding to the transmission wavelength band set by the variable filter and the position of the region; and the amplitude and amplitude of the light to be measured based on the spectrogram generated by the generator. a specifying unit that specifies the phase.

A second aspect of the present invention is the optical pulse measuring instrument according to the first aspect, wherein the wavelength tunable filter can continuously change the transmission wavelength band according to temperature.

A third aspect of the present invention is the optical pulse measuring instrument according to the first aspect or the second aspect, wherein the light detection section receives the first light to be measured from one end and the second light to be measured from the other end. The measurement light is incident, and the first light to be measured and the second light to be measured which are incident from both ends are overlapped in opposite light propagation directions to perform optical correlation.

A fourth aspect of the present invention is the optical pulse measuring instrument according to any one of the first to third aspects, wherein the light to be measured is split into the first light to be measured and the second light to be measured. Have more equipment.

A fifth aspect of the present invention is an optical pulse measurement method, wherein a processor is capable of continuously changing the transmission wavelength band of a first light to be measured split from the light to be measured. is set, and the first light to be measured that has passed through the tunable filter and the second light to be measured that is branched from the light under measurement and has not passed through the tunable filter are made incident, and generating a spectrogram based on photocurrents obtained based on power-law intensities of light at a plurality of positions in an area where the light and the second light under measurement optically overlap; and generating a spectrogram of the light under measurement based on the generated spectrogram Perform a process to identify amplitude and phase.

A fifth aspect of the present invention is an optical pulse measurement program, wherein a computer stores the transmission wavelength band of a tunable filter capable of continuously changing the transmission wavelength band of the first light to be measured branched from the light to be measured. is set, and the first light to be measured that has passed through the tunable filter and the second light to be measured that is branched from the light under measurement and has not passed through the tunable filter are made incident, and generating a spectrogram based on photocurrents obtained based on power-law intensities of light at a plurality of positions in an area where the light and the second light under measurement optically overlap; and generating a spectrogram of the light under measurement based on the generated spectrogram A process to identify amplitude and phase is performed.

According to the present invention, when measuring an optical pulse, an optical pulse signal obtained by transmitting a predetermined wavelength band of the optical pulse signal to be measured and an optical pulse signal obtained by delaying the optical pulse signal to be measured by a predetermined time are synthesized. It is possible to provide an optical pulse measuring instrument, an optical pulse measuring method, and an optical pulse measuring program capable of shortening the measurement time as compared with the case where the measurement is performed.

1 is a diagram showing a schematic configuration of an optical pulse measuring instrument according to an embodiment of the present invention; FIG. FIG. 4 is a plan view showing a configuration example of a wavelength tunable filter; It is a block diagram which shows the hardware constitutions of an information processing apparatus. 2 is a block diagram showing an example of the functional configuration of an information processing device; FIG. It is a figure explaining the measuring method of the measurement pulse by an optical pulse measuring device. It is a figure explaining the measuring method of the measurement pulse by an optical pulse measuring device. It is a figure explaining the measuring method of the measurement pulse by an optical pulse measuring device. It is a figure explaining the measuring method of the measurement pulse by an optical pulse measuring device. It is a figure explaining the measuring method of the measurement pulse by an optical pulse measuring device. FIG. 4 is a diagram showing an example of a spectrogram generated by a generation unit and an example of a shape of a measurement pulse obtained from the amplitude and phase of the measurement pulse specified by the specification unit; FIG. 13 shows an example identification of the amplitude and phase of a measured pulse from a spectrogram; FIG. 13 shows an example identification of the amplitude and phase of a measured pulse from a spectrogram; 4 is a flow chart showing the flow of measurement processing of a measurement pulse by an information processing device;

An example of an embodiment of the present invention will be described below with reference to the drawings. In each drawing, the same or equivalent components and portions are given the same reference numerals. Also, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios.

FIG. 1 is a diagram showing a schematic configuration of an optical pulse measuring instrument according to this embodiment. The optical pulse measuring instrument 100 includes a chip 10 to which an optical pulse (measurement pulse) to be measured, which is light to be measured, is input through an optical fiber cable 1, an amplifier 20 for amplifying the output of the chip 10 with a plurality of amplifiers, A multiplexer 30 for synthesizing the output of the amplifier 20, an A/D converter 40 for converting the output of the multiplexer 30 into a digital signal, and an information processing device for obtaining the characteristics of the measurement pulse using the output of the A/D converter 40. 50 and

The chip 10 includes a splitter 11 that splits the measurement pulse into two, an optical waveguide 12 that propagates the measurement pulse, a wavelength tunable filter 13 that transmits the measurement pulse, and a plurality of photodetectors arranged in an array. and a device array 14 . The optical waveguide 12 is made of, for example, a semiconductor material such as silicon, silicon nitride, or indium phosphide, or an insulating material such as SiOx.

The wavelength tunable filter 13 selects and transmits an arbitrary wavelength of the measurement pulse. In this embodiment, as the wavelength tunable filter 13, a wavelength tunable filter whose selected wavelength changes continuously according to temperature is used. FIG. 2 is a plan view showing a configuration example of the wavelength tunable filter 13. As shown in FIG. The wavelength tunable filter 13 has a looped optical waveguide 12 as shown in FIG. The temperature of the heater 62 is set according to the amount of current flowing through the electrode 61 . Heating the optical waveguide 12 by the heater 62 changes the wavelength of the measurement pulse selected and transmitted by the wavelength tunable filter 13 .

In this embodiment, the wavelength tunable filter 13 has a size that can be mounted on the chip 10, so that the wavelength tunable filter that changes the selected wavelength depending on the temperature is used. However, the present invention is not limited to such an example. As the wavelength tunable filter 13, a wavelength tunable filter whose wavelength is changed electrically or manually may be used. The optical pulse measuring instrument 100 measures the characteristics of the measurement pulse while changing the wavelength selected by the wavelength tunable filter 13 . Therefore, the optical pulse measuring instrument 100 uses a wavelength tunable filter whose wavelength can be changed by changing the temperature, compared to the case of using a wavelength tunable filter whose wavelength is changed electrically or manually. Measurement time can be shortened.

The photodetector array 14 is an example of the photodetection section of the present invention, and is composed of a plurality of photodetectors arranged in an array, in which the measurement pulse split into two by the splitter 11 is incident and optically correlated. Detect the power law intensity of light. A photodetector configured to output a current corresponding to the power of light intensity is used. The number of photodetectors can be any number, such as 32, 64, 128, etc., depending on the accuracy of the measurement of the measurement pulse. The photodetector is formed by forming an n-doped region and a p-doped region such that the adjacent portions of both doped regions are on the optical waveguide 12, the n-doped region side is connected to a DC voltage source 15, and the p-doped region side is connected to a DC voltage source 15. It has a configuration in which a current detector is connected to

For the photodetector array 14, for example, an optical correlator disclosed in Japanese Patent Application Laid-Open No. 2017-32306 can be used. The optical correlator disclosed in Japanese Unexamined Patent Application Publication No. 2017-32306 makes light pulses to be measured enter a spatial region, forms an overlapping region where both light beams overlap, and performs optical correlation by autocorrelation or cross-correlation. This overlapping region is detected by a plurality of photodetectors, and a photocurrent corresponding to the power-law intensity of the light is output.

When a plurality of photodetectors are arranged corresponding to the overlapping region of light formed by photocorrelation, the spatial distribution of the photocurrent detected at the same time from each photodetector is formed by each photocorrelation. In addition, the photocurrent sequentially detected from each photodetector represents the state change of the optical correlation at each position in the overlapping region. The photocurrent distribution in the light overlap region obtained by accumulating photocurrents obtained by photocorrelation at each position in the overlap region is simultaneously detected by each photodetector corresponding to the photocorrelation waveform of the light to be measured. By obtaining the optical correlation waveform of the light under measurement from the accumulation of the spatial distribution of the photocurrent, the waveform of the light under measurement can be obtained from the optical correlation waveform.

In this embodiment, the photodetector array 14 receives a measurement pulse (an example of first light to be measured) that has passed through the wavelength tunable filter 13 from one end, and a measurement pulse that has not passed through the wavelength tunable filter 13 from the other end. A pulse (an example of the second light to be measured) is incident. That is, the photodetector array 14 performs optical correlation by superimposing the measurement pulse that has passed through the wavelength tunable filter 13 and the measurement pulse that has not passed through the wavelength tunable filter 13 in opposite optical propagation directions. Note that both the measurement pulse that has passed through the wavelength tunable filter 13 and the measurement pulse that has not passed through the wavelength tunable filter 13 may be incident on the photodetector array 14 from the same end.

The splitter 11, the optical waveguide 12, the tunable filter 13 and the photodetector array 14 are formed on, for example, an SOI substrate. The splitter 11 is composed of, for example, a thin wire waveguide of silicon photonics, the optical waveguide 12 is composed of an optical waveguide, and the photodetector array 14 is composed of a plurality of pn diodes integrated in the optical waveguide to detect distributed two-photon absorption photons. It consists of a plurality of photodetectors formed by constructing diodes.

The amplifier section 20 has a plurality of amplifiers arranged in parallel. Each amplifier amplifies the output of one photodetector by a predetermined amount and outputs it.

The multiplexer 30 multiplexes the output of each amplifier of the amplification section 20 and outputs the multiplexed output. The A/D converter 40 converts the output of the multiplexer 30, which is an analog signal, into a digital signal.

The information processing device 50 generates a spectrogram from the output of the A/D converter 40 and determines the phase and amplitude of the measurement pulse based on the generated spectrogram, thereby measuring the characteristics of the measurement pulse. A method of measuring the characteristics of the measurement pulse by the information processing device 50 will be described in detail later.

The optical pulse measuring instrument 100 according to the present embodiment is compact, lightweight, easy to handle, mechanically robust, and optically stable by providing the wavelength tunable filter 13 and the photodetector array 14 on the chip 10 . It has a feature that alignment becomes unnecessary.

FIG. 3 is a block diagram showing the hardware configuration of the information processing device 50. As shown in FIG.

As shown in FIG. 3, the information processing device 50 includes a CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 52, a RAM (Random Access Memory) 53, a storage 54, an input unit 55, a display unit 16, and a communication interface. (I/F) 57. Each component is communicatively connected to each other via a bus 59 .

The CPU 51 is a central processing unit that executes various programs and controls each section. That is, the CPU 51 reads a program from the ROM 52 or the storage 54 and executes the program using the RAM 53 as a work area. The CPU 51 performs control of the above components and various arithmetic processing according to programs recorded in the ROM 52 or the storage 54 . In this embodiment, the ROM 52 or storage 54 stores a measurement program for measuring the characteristics of the measurement pulse.

The ROM 52 stores various programs and various data. RAM 53 temporarily stores programs or data as a work area. The storage 54 is configured by a storage device such as a HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory, and stores various programs including an operating system and various data.

The input unit 55 includes a pointing device such as a mouse and a keyboard, and is used for various inputs.

The display unit 56 is, for example, a liquid crystal display, and displays various information. The display unit 56 may employ a touch panel system and function as the input unit 55 .

The communication interface 57 is an interface for communicating with other devices, and uses standards such as Ethernet (registered trademark), FDDI, and Wi-Fi (registered trademark), for example.

When executing the above measurement program, the information processing device 50 uses the above hardware resources to implement various functions. A functional configuration realized by the information processing device 50 will be described.

FIG. 4 is a block diagram showing an example of the functional configuration of the information processing device 50. As shown in FIG.

As shown in FIG. 4, the information processing apparatus 50 has a generation unit 501, a specification unit 502, a display unit 503, and a setting unit 504 as functional configurations. Each functional configuration is realized by the CPU 51 reading and executing a measurement program stored in the ROM 52 or storage 54 .

A generator 501 generates a spectrogram from the output of the A/D converter 40 . In this embodiment, the generating unit 501 generates the intensity of the measurement pulse, with the horizontal axis representing the position of each photodetector in the photodetector array 14 and the vertical axis representing the center wavelength _λn of the wavelength set by the wavelength tunable filter 13. Generate a spectrogram representing . The spectrogram generated by the generator 501 is a spectrogram representing the strength of the photocurrent signal output from the A/D converter 40 .

The specifying unit 502 specifies the amplitude and phase of the measurement pulse based on the spectrogram generated by the generating unit 501 . Specifically, the specifying unit 502 uses a characteristic function obtained by performing a double inverse Fourier transform on the spectrogram and an ambiguity function of the impulse response of the wavelength tunable filter that has been acquired in advance to determine a predetermined value for the spectrogram. Arithmetic processing identifies the amplitude and phase of the measurement pulse backwards. Methods for determining the amplitude and phase of the measured pulse based on the spectrogram are described, for example, in Kazuro Kikuchi and Kenji Taira, "Theory of sonogram characterization of optical pulses", IEEE Journal of Quantum Electronics, Volume 37, Issue 4, April 2001. The methods disclosed can be used.

The display unit 503 displays information about the measurement pulse whose amplitude and phase are specified as a result of the predetermined arithmetic processing performed by the specifying unit 502 . For example, the display unit 503 displays the amplitude, phase, outline of the waveform obtained from the amplitude and phase, etc. of the measurement pulse as information on the measurement pulse.

The setting unit 504 sets the wavelength selected by the wavelength tunable filter 13 . When the measurement pulse is measured by the optical pulse measuring instrument 100, the photocurrent is measured while the set wavelength is changed by the wavelength tunable filter 13 as described above. , may be performed by the setting unit 504 or may be performed by a device other than the information processing device 50 .

Next, a method of measuring a measurement pulse by the optical pulse measuring instrument according to this embodiment will be described.

5 to 9 are diagrams for explaining the method of measuring the measurement pulse by the optical pulse measuring instrument according to this embodiment. 5 to 9 are graphs of the magnitude of the photocurrent detected by each photodetector of the photodetector array 14 when the wavelength set by the wavelength tunable filter 13 is sequentially changed from _λ1 to _λ5 . An example is shown together with the configuration of the optical pulse measuring instrument. In the graphs shown in FIGS. 5 to 9, the horizontal axis represents the position of each photodetector in the photodetector array 14 (unit: m), and the vertical axis represents the magnitude of the photocurrent detected by each photodetector (unit: A). ). The graphs shown in FIGS. 5 to 9 are examples in which the frequency of the carrier wave is modulated inside the measurement pulse.

In the examples shown in FIGS. 5 to 9, when the wavelength set by the wavelength tunable filter 13 is changed in order from λ ₁ to λ ₅ , the peak position of the magnitude of the photocurrent changes in order. In the examples shown in FIGS. 5 to 9, when the wavelength set by the wavelength tunable filter 13 is changed in order from λ ₁ to λ ₅ , the magnitude of the photocurrent peak also changes. In the examples shown in FIGS. 5 to 9, when the wavelength is _λ3 , the peak position of the magnitude of the photocurrent is at the center of the photodetector array 14, and the peak magnitude of the photocurrent is also the largest.

Thus, when the wavelength is set by the wavelength tunable filter 13, the peak position of the photocurrent detected by the photodetector array 14 and the magnitude at the peak position change according to the set wavelength. The information processing device 50 uses the measurement result of the magnitude of the photocurrent obtained in this way to set the horizontal axis to the position of each photodetector in the photodetector array 14 and the vertical axis to the wavelength tunable filter 13. A generating unit 501 generates a spectrogram with the set wavelength.

FIG. 10 is a diagram showing an example of a spectrogram generated by the generation unit 501 and an example of the shape of the measurement pulse obtained from the amplitude and phase of the measurement pulse identified by the identification unit 502. FIG. As shown in the upper part of FIG. 10, the generation unit 501 generates a spectrogram from the measurement result of the magnitude of the photocurrent. Then, the specifying unit 502 can specify the amplitude and phase of the measurement pulse and the shape of the carrier wave of the measurement pulse by performing calculation processing on the spectrogram generated by the generation unit 501 .

FIG. 11 shows a specific example of the amplitude and phase of the measured pulse from the spectrogram. FIG. 11 shows an example when the chirp coefficient C of the measured pulse is C=0. FIG. 11(a) is the spectrogram generated by the generation unit 501, and FIG. 11(b) is the spectrogram obtained by the identification unit 502 The amplitude of the measurement pulse and FIG. 11(c) are the phases of the measurement pulse obtained from the spectrogram by the identifying unit 502 . FIGS. 11(b) and 11(c) show the identification result by the identification unit 502 and the actual amplitude and phase of the measured pulse.

As shown in FIG. 11B, as a result of specifying the amplitude by the specifying unit 502, it can be seen that the actual amplitude of the measurement pulse and the amplitude specified by the specifying unit 502 match very accurately. Then, as shown in FIG. 11C, as a result of specifying the phase by the specifying unit 502, the actual phase of the measurement pulse and the phase specified by the specifying unit 502 differ from each other within the range where the amplitude can be specified. It can be seen that they match very accurately.

FIG. 12 shows a specific example of the amplitude and phase of the measured pulse from the spectrogram. FIG. 12 shows an example in which the chirp coefficient C of the measured pulse is C=4×10 ²³ , FIG. 12(a) is the spectrogram generated by the generator 501, and FIG. FIG. 12(c) is the phase of the measurement pulse obtained from the spectrogram by the specifying unit 502. FIG. 12(b) and (c) show the identification result by the identification unit 502 and the actual amplitude and phase of the measured pulse.

As shown in FIG. 12B, as a result of specifying the amplitude by the specifying unit 502, it can be seen that the actual amplitude of the measurement pulse and the amplitude specified by the specifying unit 502 match very accurately. Then, as shown in FIG. 12(c), as a result of the phase identification by the identification unit 502, the actual phase of the measurement pulse and the phase identified by the identification unit 502 differ from each other within the range where the amplitude can be identified. It can be seen that they match very accurately.

Next, the action of the information processing device 50 will be described.

FIG. 13 is a flow chart showing the flow of measurement pulse measurement processing by the information processing device 50 . The CPU 51 reads the measurement program from the ROM 52 or the storage 54, develops it in the RAM 53, and executes it, thereby performing measurement processing of the measurement pulse.

The CPU 51 first sets the wavelength selected by the wavelength tunable filter 13 in step S101.

After setting the wavelength selected by the wavelength tunable filter 13, the CPU 51 acquires the intensity of the photocurrent detected by the photodetector array 14 in step S102.

After acquiring the intensity of the photocurrent detected by the photodetector array 14, the CPU 51 subsequently determines in step S103 whether or not there are wavelengths to be set in the measurement pulse measurement process. As a result of the determination in step S103, if there are still wavelengths to be set, the CPU 51 returns to step S101 and sets the wavelength selected by the wavelength tunable filter 13 again. On the other hand, as a result of the determination in step S103, if there is no wavelength to be set, the CPU 51 generates a spectrogram using the photocurrent intensity data detected by the photodetector array 14 in step S104. .

After generating the spectrogram using the photocurrent intensity data, the CPU 51 then identifies the amplitude and phase of the measurement pulse from the generated spectrogram in step S105.

After identifying the amplitude and phase of the measurement pulse from the spectrogram, the CPU 51 subsequently displays information on the measurement pulse in step S106. For example, the CPU 51 displays the amplitude, phase, outline of the waveform obtained from the amplitude and phase, etc. of the measurement pulse as information on the measurement pulse.

There is an increasing demand for measurement of high-speed optical pulses with a pulse width of 100 ps or less, particularly 10 ps or less. If the amplitude shape (envelope) and phase of a high-speed, short-period optical pulse signal can be measured, the shape of the carrier wave can be grasped, and detailed time characteristics of the optical pulse signal can be clarified. However, when an oscilloscope is used for observation, even the observation of the envelope becomes difficult when the optical pulse signal has a short period. Therefore, a dedicated device is used for observing the waveform of the high-speed optical pulse signal.

Conventional methods for observing the waveform of an optical pulse signal include the Frequency Resolved Optical Gating (FROG) method and the SPIDER (Spectral Phase Interferometry for Direct Electric-field Reconstruction) method. However, the measurement devices using these methods are large, heavy, mechanically fragile, and require precise alignment during measurement, but have the problem of low sensitivity.

On the other hand, the optical pulse measuring instrument 100 according to the present embodiment is small and lightweight because the photodetector array 14 is incorporated in the chip 10, unlike the conventional optical pulse signal measuring device. Optical pulses can be measured anywhere. In addition, the optical pulse measuring instrument 100 according to this embodiment is solid-state, mechanically robust, and does not require optical alignment because the photodetector array 14 is incorporated in the chip 10 . Furthermore, the optical pulse measuring instrument 100 according to this embodiment can perform measurement with high sensitivity because the measurement pulses are concentrated in a very small area. Further, since the optical pulse measuring instrument 100 according to the present embodiment does not require delayed scanning, it is possible to shorten the measurement time of the measurement pulse compared to the measurement method requiring delayed scanning.

Note that various processors other than the CPU may execute the measurement pulse measurement processing executed by the CPU by reading the software (program) in each of the above-described embodiments. In this case, the processor is a PLD (Programmable Logic Device) whose circuit configuration can be changed after manufacturing, such as an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit) for executing specific processing. A dedicated electric circuit or the like, which is a processor having a specially designed circuit configuration, is exemplified. Moreover, the measurement processing of the measurement pulse may be performed by one of these various processors, or by a combination of two or more processors of the same or different type (for example, multiple FPGAs, and a CPU and an FPGA). , etc.). More specifically, the hardware structure of these various processors is an electric circuit in which circuit elements such as semiconductor elements are combined.

Further, in each of the above-described embodiments, a mode in which a program for measurement processing of measurement pulses is stored (installed) in advance in a ROM or storage has been described, but the present invention is not limited to this. The program is recorded on a non-transitory recording medium such as CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), and USB (Universal Serial Bus) memory. may be provided in the form Also, the program may be downloaded from an external device via a network.

1 optical fiber cable 10 chip 11 splitter 12 optical waveguide 13 wavelength tunable filter 14 photodetector array 20 amplifier 30 multiplexer 40 A/D converter 50 information processing device 100 optical pulse measuring instrument

Claims (6)

a variable wavelength filter capable of continuously changing the transmission wavelength band of the first light under measurement split from the light under measurement;
The first light to be measured that has passed through the wavelength tunable filter and the second light to be measured that is branched from the light to be measured and has not passed through the wavelength tunable filter are made incident, and the first light to be measured and the second light to be measured are injected. 2. Light obtained by arranging a plurality of photodetectors arranged in an array along the area where the light to be measured optically overlaps, and which outputs photocurrents obtained based on the power-law intensity of the light at a plurality of positions in the area. a detection unit;
a generation unit that generates a spectrogram based on the photocurrent corresponding to the transmission wavelength band set by the wavelength tunable filter and the position of the region;
a specifying unit that specifies the amplitude and phase of the light under measurement based on the spectrogram generated by the generating unit;
An optical pulse meter, comprising: 2. The optical pulse measuring instrument according to claim 1, wherein said wavelength tunable filter can continuously change said transmission wavelength band according to temperature. The photodetector receives the first light to be measured from one end, receives the second light to be measured from the other end, and detects the first light to be measured and the second light to be measured that are incident from both ends. 3. The optical pulse measuring instrument according to claim 1, wherein optical correlation is performed by superimposing in opposite light propagation directions. 4. The optical pulse measuring instrument according to claim 1, further comprising a splitter for splitting the light under measurement into the first light under measurement and the second light under measurement. the processor
setting the transmission wavelength band of a tunable filter capable of continuously changing the transmission wavelength band of the first measured light branched from the measured light;
The first light to be measured that has passed through the wavelength tunable filter and the second light to be measured that is branched from the light to be measured and has not passed through the wavelength tunable filter are made incident, and the first light to be measured and the second light to be measured are injected. 2 generating a spectrogram based on photocurrents obtained based on power-law intensities of light at a plurality of positions in an area where the light to be measured optically overlaps;
An optical pulse measurement method, comprising specifying the amplitude and phase of the light to be measured based on the generated spectrogram. to the computer,
setting the transmission wavelength band of a tunable filter capable of continuously changing the transmission wavelength band of the first measured light branched from the measured light;
The first light to be measured that has passed through the wavelength tunable filter and the second light to be measured that is branched from the light to be measured and has not passed through the wavelength tunable filter are made incident, and the first light to be measured and the second light to be measured are injected. 2 generating a spectrogram based on photocurrents obtained based on power-law intensities of light at a plurality of positions in an area where the light to be measured optically overlaps;
An optical pulse measurement program for executing a process of specifying the amplitude and phase of the light to be measured based on the generated spectrogram.