Aging device of modulator and modulator reliability test system

Abstract

The invention relates to the field of chip reliability testing, in particular to an aging device of a modulator and a modulator reliability testing system. The aging device of the modulator comprises a test board used for bearing a plurality of test chips of the modulator. The light loading unit is used for inputting laser with rated power to each test chip. The frequency synthesizer is used for generating a periodic alternating-current radio-frequency signal. And the power divider unit is connected with the test chips, and the power divider unit is used for dividing the single-path radio frequency signal generated by the frequency synthesizer into multiple paths of radio frequency electric signals and inputting each path of radio frequency electric signal into one test chip. The frequency synthesizer is arranged in the aging device of the modulator, so that the aging device has both optical input and radio frequency driving functions. And the radio-frequency signals are shunted by utilizing a cascade form of the power divider units so as to input the radio-frequency signals with the same amplitude to a plurality of test chips at the same time, so that the aging test efficiency is improved, and the aging test of the test chips on a large scale is met.

Description

Technical Field

[0001] The invention relates to the field of chip reliability testing, and in particular to an aging device for a modulator and a modulator reliability testing system. Background Art

[0002] As the core transmitting component in the field of optical communication transmission, the modulator chip is becoming more and more important as the amount of data continues to rise. The intensity modulator based on lithium niobate is widely used in fields such as electro-optical modulation due to its advantages such as high bandwidth, low insertion loss, low power consumption, good linearity, and high extinction ratio. The reliability test of the chip is an extremely important experimental link before the chip is mass-produced. The aging test in the reliability test can accelerate the aging of the chip and then evaluate the service life of the chip. As an electro-optical conversion and transmission unit, the chip structure of the lithium niobate modulator needs to take into account three different functions: optical, electrical, and radio frequency. Therefore, its automated aging test system needs to be compatible with the characteristics of optical output, optical detection, radio frequency signal input, and DC signal loading. At the same time, the lithium niobate modulator chip is prone to drift due to its own operating point, so its automated aging system also needs to take into account the automatic bias control function of the modulator.

[0003] At present, there are few batch automated aging devices based on lithium niobate modulators on the market, and their functions are relatively simple. Generally, they only have light detection and DC signal loading, and rarely take into account the RF driving function. In addition, the RF driving components in related equipment are difficult to meet the aging test of large quantities of test chips. Therefore, the development of its automated aging system has the advantages of high efficiency and convenience for batch screening and evaluation of test chips, which is of great significance for promoting the application of lithium niobate test chips in the field of optoelectronic transmission. Summary of the invention

[0004] In the related art, the RF driving function of the batch automated aging device of the modulator is difficult to meet the aging test of a large number of test chips.

[0005] In a first aspect, an embodiment of the present application provides an aging device for a modulator, comprising:

[0006] A test board, on which a plurality of test chips of the modulator are carried;

[0007] A light loading unit, used for inputting a laser with rated power into each of the test chips;

[0008] A frequency synthesizer for generating a periodic AC radio frequency signal;

[0009] A power divider unit connected to the test chip, and used for dividing the single-channel radio frequency signal generated by the frequency synthesizer into multiple channels of radio frequency electrical signals with equal amplitude, and inputting each channel of radio frequency electrical signal into one of the test chips;

[0010] A control unit is connected to the frequency synthesizer and the light loading unit signal, and the control unit is used to adjust the light emitting power of the light loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

[0011] In combination with the first aspect, in one implementation, the light loading unit includes:

[0012] a laser, which is signal-connected to the control unit;

[0013] A plurality of optical beam splitters, one end of which is connected to the laser, and the optical beam splitter is used to split a light path emitted by the laser into a plurality of output light paths with the same power.

[0014] In combination with the first aspect, in one embodiment, the optical loading unit further includes: a plurality of erbium-doped fiber amplifiers, the number of which corresponds to the number of the plurality of output optical paths of the optical beam splitter, each of the erbium-doped fiber amplifiers is connected to an output optical path of the optical beam splitter at one end and connected to the test chip at the other end, and the erbium-doped fiber amplifier is used to amplify the output power of the output optical path of the optical beam splitter.

[0015] In combination with the first aspect, in one embodiment, the aging device of the modulator also includes: an automatic bias control unit, whose input end is connected to the control unit signal, the output end of the automatic bias control unit is connected to the DC bias input port of the test chip, and the automatic bias control unit is used to adjust the working state of the test chip in real time to keep the test chip working at an optimal working point.

[0016] In combination with the first aspect, in one implementation, the aging device of the modulator further includes: a photodetector, which is signal-connected to the control unit, and the photodetector is used to detect output optical power data of an output optical port of the test chip.

[0017] In combination with the first aspect, in one implementation, the photodetector is signal-connected to the control unit via a current-to-voltage conversion circuit.

[0018] In combination with the first aspect, in one embodiment, the aging device of the modulator also includes: a host computer, which is signal-connected to the control unit, and the host computer is used to issue instructions to the control unit to adjust the rated output power of the optical loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

[0019] In combination with the first aspect, in one implementation, the control unit is provided with a data uploading unit, and the data uploading unit is used to receive the output optical power data detected by the photoelectric detector, and upload the output optical power data to a host computer for storage and display.

[0020] In combination with the first aspect, in one implementation, the aging device of the modulator further includes: a control board on which the frequency synthesizer, the power divider unit, the control unit, the automatic bias control unit and the photodetector are mounted.

[0021] In a second aspect, an embodiment of the present application provides a modulator reliability testing system, which includes: an aging device for the modulator as described in any one of the above.

[0022] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0023] The present application sets a frequency synthesizer in the aging device of the modulator so that the aging device takes into account both the optical input and RF driving functions. Furthermore, the output end of the frequency synthesizer of the present application is provided with a power divider unit, and the cascaded form of the power divider unit is used to realize the RF signal branching so as to input the same amplitude RF signal to multiple test chips at the same time, thereby improving the aging test efficiency and meeting the aging test of a large number of test chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic diagram of a control panel in an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of a light loading unit in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of an aging device for a modulator in an embodiment of the present application;

[0028] Figure 4 Schematic diagram of a lithium niobate modulator test chip in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] In the related art, the RF driving function of the batch automated aging device of the modulator is difficult to meet the aging test of a large number of test chips.

[0031] First, as Figure 1 As shown, an embodiment of the present application provides an aging device for a modulator, which includes: a test board, an optical loading unit, a frequency synthesizer, a power divider unit and a control unit; wherein,

[0032] A test board, on which a plurality of test chips of the modulator are carried. A light loading unit, which is used to input a laser of rated power into each of the test chips. A frequency synthesizer, which is used to generate a periodic AC radio frequency signal. A power divider unit, which is connected to the test chip, and the power divider unit is used to divide the single radio frequency signal generated by the frequency synthesizer into multiple radio frequency electrical signals of equal amplitude, and input each radio frequency electrical signal into one of the test chips. A control unit, which is signal-connected to the frequency synthesizer and the light loading unit, and the control unit is used to adjust the light emitting power of the light loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

[0033] It should be noted that the frequency synthesizer (DDS signal generating unit) can generate a periodic AC radio frequency signal of a certain frequency (0-500 MHz). The control unit can be a micro control unit (MCU control unit).

[0034] It is worth noting that the present application provides a frequency synthesizer in the aging device of the modulator so that the aging device takes into account both the optical input and RF driving functions. Furthermore, the output end of the frequency synthesizer of the present application is provided with a power divider unit, and the cascaded form of the power divider unit is used to realize the branching of the RF signal so as to input RF signals of equal amplitude to multiple test chips at the same time, thereby improving the aging test efficiency and meeting the aging test of a large number of test chips.

[0035] In some optional implementations, the power splitter unit is used to split the single-channel RF signal generated by the frequency synthesizer into multiple RF electrical signals of equal amplitude. And the number of multiple RF electrical signals is the same as the number of multiple optical paths generated by the optical loading unit. Several power splitters can be in the form of 1-to-2 or 1-to-4 splitters, etc., which are cascaded to achieve 1-to-n RF signals, one end of which is optically connected to the frequency synthesizer, and the other end is connected to the test board such as Figure 4 The RF input port (radio frequency input interface) of each test chip to be aged is shown.

[0036] In combination with the first aspect above, in some implementation modes, Figure 2 As shown, the light loading unit includes: a laser and a plurality of light beam splitters; wherein,

[0037] A laser is connected to the control unit signal. A plurality of optical beam splitters, one end of which is connected to the laser, and the optical beam splitters are used to split a light path emitted by the laser into a plurality of output light paths with the same power.

[0038] It is understandable that a test chip with excellent performance needs to have the characteristics of high reliability, stable performance and long service life. Some modulators (such as lithium niobate modulators) are used as electro-optical conversion and transmission units, such as Figure 4 As shown, the chip structure needs to take into account three different functions: optical, electrical, and radio frequency. In order to improve the efficiency of aging testing, the optical loading unit also needs to simultaneously transmit output optical paths with the same power to multiple test chips.

[0039] Furthermore, the laser may be a 1550nm or 1310nm laser. The multiple optical beam splitters may be in the form of a 1-to-2 beam splitter or a 1-to-4 beam splitter, etc., which are cascaded to realize 1-to-n optical paths, and one end of the optical path is connected to the laser unit.

[0040] In some preferred embodiments, the optical loading unit further includes: a plurality of erbium-doped fiber amplifiers (EDFA), the number of which corresponds to the number of the plurality of output optical paths of the optical beam splitter, each of the erbium-doped fiber amplifiers is connected to an output optical path of the optical beam splitter at one end and connected to the test chip at the other end, and the erbium-doped fiber amplifier is used to amplify the output power of the output optical path of the optical beam splitter.

[0041] It can be understood that the multiple erbium-doped fiber amplifiers are used to compensate for the laser light power loss caused by splitting. The number of the multiple erbium-doped fiber amplifiers is equal to the number of multiple light paths generated by the beam splitter, which are used to input rated power light to each aging modulator chip.

[0042] In some optional implementations, the aging device of the modulator also includes: an automatic bias control unit, whose input end is connected to the control unit signal, the output end of the automatic bias control unit is connected to the DC bias input port of the test chip, and the automatic bias control unit is used to adjust the working state of the test chip in real time to keep the test chip working at an optimal working point.

[0043] It is worth noting that the automatic bias control unit is used to adjust the working state of each modulator chip in the test board in real time to ensure that the modulator chip works at the optimal working point. Its output port is directly connected to the DC bias input port (DC bias port) of each modulator chip.

[0044] In some preferred implementations, the aging device of the modulator further includes: a photodetector (PD detection unit), which is signal-connected to the control unit, and the photodetector is used to detect output optical power data of the output optical port of the test chip.

[0045] It can be understood that the photodetector can detect the output optical power value of the test chip output optical port of the modulator.

[0046] Furthermore, the photodetector is signal-connected to the control unit via a current-voltage conversion circuit.

[0047] In some optional implementations, the aging device of the modulator also includes: a host computer, which is signal-connected to the control unit, and the host computer is used to issue instructions to the control unit to adjust the rated output power of the optical loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

[0048] Furthermore, the control unit is provided with a data uploading unit, and the data uploading unit is used to receive the output optical power data detected by the photoelectric detector, and upload the output optical power data to the host computer for storage and display.

[0049] In some preferred implementations, Figure 3 As shown, the aging device of the modulator also includes: a control board, on which the frequency synthesizer, the power divider unit, the control unit, the automatic bias control unit and the photodetector are installed.

[0050] It is understandable that the control board has a relatively complex function. On the one hand, it receives instructions from the host computer, and on the other hand, the control board generates the radio frequency electrical signal required for modulator aging. The control board also has the function of detecting the optical power output by the modulator and locking the working state of the modulator in real time based on its own automatic bias control function. The test board is placed in the aging box and connected to the optical, electrical, and radio frequency signals of the control board. It is used to carry the lithium niobate modulator chip components and complete the aging of the optical, electrical, and radio frequency characteristics of the chip.

[0051] The use process of the aging device of the modulator of the present application includes: placing the test chips of the modulator in batches into a high-temperature aging box, powering on the entire aging test system, and then setting the optical power value output by the optical loading unit and the amplitude and frequency of the radio frequency signal generated by the frequency synthesizer through the host computer software. After receiving the host computer command, the control board sets the working state of the entire system and then starts the aging test. After that, the control board adjusts the working state of each modulator chip in real time through the automatic bias control unit, detects the output optical power value of the modulator output optical port through the photoelectric detector, and uploads the data of the modulator chip to the host computer in real time for storage and display.

[0052] In a second aspect, the present application provides a modulator reliability test system, which includes: an aging device for a modulator, the aging device including: a test board, an optical loading unit, a frequency synthesizer, a power divider unit and a control unit; wherein,

[0053] A test board, on which a plurality of test chips of the modulator are carried. A light loading unit, which is used to input a laser of rated power into each of the test chips. A frequency synthesizer, which is used to generate a periodic AC radio frequency signal. A power divider unit, which is connected to the test chip, and the power divider unit is used to divide the single radio frequency signal generated by the frequency synthesizer into multiple radio frequency electrical signals of equal amplitude, and input each radio frequency electrical signal into one of the test chips. A control unit, which is signal-connected to the frequency synthesizer and the light loading unit, and the control unit is used to adjust the light emitting power of the light loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

[0054] It should be noted that the frequency synthesizer (DDS signal generating unit) can generate a periodic AC radio frequency signal of a certain frequency (0-500 MHz). The control unit can be a micro control unit (MCU control unit).

[0055] It is worth noting that the present application provides a frequency synthesizer in the aging device of the modulator so that the aging device takes into account both the optical input and RF driving functions. Furthermore, the output end of the frequency synthesizer of the present application is provided with a power divider unit, and the cascaded form of the power divider unit is used to realize the branching of the RF signal so as to input RF signals of equal amplitude to multiple test chips at the same time, thereby improving the aging test efficiency and meeting the aging test of a large number of test chips.

[0056] In some optional implementations, the power splitter unit is used to split the single-channel RF signal generated by the frequency synthesizer into multiple RF electrical signals of equal amplitude. And the number of multiple RF electrical signals is the same as the number of multiple optical paths generated by the optical loading unit. Several power splitters can be in the form of 1-to-2 or 1-to-4 splitters, etc., which are cascaded to achieve 1-to-n RF signals, one end of which is optically connected to the frequency synthesizer, and the other end is connected to the test board such as Figure 4 The RF input port (radio frequency input interface) of each test chip to be aged is shown.

[0057] In combination with the first aspect above, in some implementation modes, Figure 2 As shown, the light loading unit includes: a laser and a plurality of light beam splitters; wherein,

[0058] A laser is connected to the control unit signal. A plurality of optical beam splitters, one end of which is connected to the laser, and the optical beam splitters are used to split a light path emitted by the laser into a plurality of output light paths with the same power.

[0059] It is understandable that a test chip with excellent performance needs to have the characteristics of high reliability, stable performance and long service life. Some modulators (such as lithium niobate modulators) are used as electro-optical conversion and transmission units, such as Figure 4 As shown, the chip structure needs to take into account three different functions: optical, electrical, and radio frequency. In order to improve the efficiency of aging testing, the optical loading unit also needs to simultaneously transmit output optical paths with the same power to multiple test chips.

[0060] Furthermore, the laser may be a 1550nm or 1310nm laser. The multiple optical beam splitters may be in the form of a 1-to-2 beam splitter or a 1-to-4 beam splitter, etc., which are cascaded to realize 1-to-n optical paths, and one end of the optical path is connected to the laser unit.

[0061] In some preferred embodiments, the optical loading unit further includes: a plurality of erbium-doped fiber amplifiers (EDFA), the number of which corresponds to the number of the plurality of output optical paths of the optical beam splitter, each of the erbium-doped fiber amplifiers is connected to an output optical path of the optical beam splitter at one end and connected to the test chip at the other end, and the erbium-doped fiber amplifier is used to amplify the output power of the output optical path of the optical beam splitter.

[0062] It can be understood that the multiple erbium-doped fiber amplifiers are used to compensate for the laser light power loss caused by splitting. The number of the multiple erbium-doped fiber amplifiers is equal to the number of multiple light paths generated by the beam splitter, which are used to input rated power light to each aging modulator chip.

[0063] In some optional implementations, the aging device of the modulator also includes: an automatic bias control unit, whose input end is connected to the control unit signal, the output end of the automatic bias control unit is connected to the DC bias input port of the test chip, and the automatic bias control unit is used to adjust the working state of the test chip in real time to keep the test chip working at an optimal working point.

[0064] It is worth noting that the automatic bias control unit is used to adjust the working state of each modulator chip in the test board in real time to ensure that the modulator chip works at the optimal working point. Its output port is directly connected to the DC bias input port (DC bias port) of each modulator chip.

[0065] In some preferred implementations, the aging device of the modulator further includes: a photodetector (PD detection unit), which is signal-connected to the control unit, and the photodetector is used to detect output optical power data of the output optical port of the test chip.

[0066] It can be understood that the photodetector can detect the output optical power value of the test chip output optical port of the modulator.

[0067] Furthermore, the photodetector is signal-connected to the control unit via a current-voltage conversion circuit.

[0068] In some optional implementations, the aging device of the modulator also includes: a host computer, which is signal-connected to the control unit, and the host computer is used to issue instructions to the control unit to adjust the rated output power of the optical loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

[0069] Furthermore, the control unit is provided with a data uploading unit, and the data uploading unit is used to receive the output optical power data detected by the photoelectric detector, and upload the output optical power data to the host computer for storage and display.

[0070] In some preferred implementations, Figure 3 As shown, the aging device of the modulator also includes: a control board, on which the frequency synthesizer, the power divider unit, the control unit, the automatic bias control unit and the photodetector are installed.

[0071] It is understandable that the control board has a relatively complex function. On the one hand, it receives instructions from the host computer, and on the other hand, the control board generates the radio frequency electrical signal required for modulator aging. The control board also has the function of detecting the optical power output by the modulator and locking the working state of the modulator in real time based on its own automatic bias control function. The test board is placed in the aging box and connected to the optical, electrical, and radio frequency signals of the control board. It is used to carry the lithium niobate modulator chip components and complete the aging of the optical, electrical, and radio frequency characteristics of the chip.

[0072] In summary, the present application sets a frequency synthesizer in the aging device of the modulator so that the aging device takes into account both the optical input and RF driving functions. Furthermore, the present application has a power divider unit at the output end of the frequency synthesizer, and utilizes the cascade form of the power divider unit to realize the branching of the RF signal so as to input RF signals of equal amplitude to multiple test chips at the same time, thereby improving the aging test efficiency and meeting the aging test of large quantities of test chips. The present application is based on a batch automated aging test system of a lithium niobate modulator, which integrates optical signals, electrical signals, RF signals, automatic bias control, etc. into the automated aging test system, and can guarantee the aging effect to the maximum extent. It ensures batch aging testing of chips through 1-to-n optical signal loading and 1-to-n RF signal loading, greatly improving the test efficiency.

[0073] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0074] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0075] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A modulator aging device, characterized in that: include: A test board, on which a plurality of test chips of the modulator are carried; A light loading unit, used for inputting a laser with rated power into each of the test chips; A frequency synthesizer for generating a periodic AC radio frequency signal; A power divider unit connected to the test chip, and used for dividing the single-channel radio frequency signal generated by the frequency synthesizer into multiple channels of radio frequency electrical signals with equal amplitude, and inputting each channel of radio frequency electrical signal into one of the test chips; A control unit is connected to the frequency synthesizer and the light loading unit signal, and the control unit is used to adjust the light emitting power of the light loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

2. The aging device for a modulator according to claim 1, characterized in that: The light loading unit comprises: a laser, which is signal-connected to the control unit; A plurality of optical beam splitters, one end of which is connected to the laser, and the optical beam splitter is used to split a light path emitted by the laser into a plurality of output light paths with the same power.

3. The aging device of the modulator according to claim 2, characterized in that: The optical loading unit also includes: multiple erbium-doped fiber amplifiers, the number of which corresponds to the number of the multiple output optical paths of the optical splitters, each of the erbium-doped fiber amplifiers is connected to an output optical path of the optical splitter at one end and connected to the test chip at the other end, and the erbium-doped fiber amplifier is used to amplify the output power of the output optical path of the optical splitter.

4. The aging device for a modulator according to claim 1, characterized in that: The aging device of the modulator also includes: an automatic bias control unit, whose input end is connected to the control unit signal, and the output end of the automatic bias control unit is connected to the DC bias input port of the test chip. The automatic bias control unit is used to adjust the working state of the test chip in real time so that the test chip can keep working at the optimal working point.

5. The aging device for a modulator according to claim 4, characterized in that: The aging device of the modulator also includes: a photoelectric detector, which is connected to the control unit signal, and the photoelectric detector is used to detect the output optical power data of the output optical port of the test chip.

6. The aging device for a modulator as claimed in claim 5, characterized in that: The photoelectric detector is connected to the control unit signal through a current-voltage conversion circuit.

7. The aging device for a modulator according to claim 5, characterized in that: The aging device of the modulator also includes: a host computer, which is connected to the control unit signal, and the host computer is used to issue instructions to the control unit to adjust the rated output power of the optical loading unit and the frequency of the radio frequency signal emitted by the frequency synthesizer.

8. The aging device for a modulator as claimed in claim 7, characterized in that: The control unit is provided with a data uploading unit, and the data uploading unit is used to receive the output optical power data detected by the photoelectric detector, and upload the output optical power data to the host computer for storage and display.

9. The aging device for a modulator according to claim 5, characterized in that: The aging device of the modulator also includes: a control board, on which the frequency synthesizer, the power divider unit, the control unit, the automatic bias control unit and the photoelectric detector are installed.

10. A modulator reliability test system, characterized in that: include: An aging device for a modulator as claimed in any one of claims 1 to 9.

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