JP4859250B2 - Distance adjustment apparatus and method for inspection object, inspection apparatus and method - Google Patents

Description

The present invention relates to a distance adjustment apparatus and method for an object (inspection object), an inspection apparatus and method for an object (inspection object), and the like. In particular, a distance adjustment apparatus and method for adjusting the distance to an inspection object using a high-frequency electromagnetic wave (also referred to as a terahertz wave in this specification) having an arbitrary frequency band within a frequency range of 30 GHz to 30 THz, and the inspection object The present invention relates to an inspection apparatus and an inspection method.

In recent years, nondestructive sensing technology using terahertz waves has been developed. As an application field of electromagnetic waves in this frequency band, a technique for performing imaging using a safe fluoroscopic inspection apparatus replacing X-rays has been developed. In addition, a spectroscopic technique for obtaining an absorption spectrum and a complex dielectric constant inside a substance and examining physical properties such as a binding state, a biomolecule analysis technique, and a technique for evaluating carrier concentration and mobility have been developed.

An apparatus for inspecting an object using terahertz waves is disclosed in Patent Document 1. This inspection apparatus is an apparatus that irradiates an object with a terahertz wave propagating in space and measures the characteristics of the constituent material of the object by changing the propagation state of the transmitted wave from the object. In this proposal, a transmission imaging image inside the object is obtained by scanning the object two-dimensionally.

On the other hand, it is known that terahertz waves propagate through transmission lines used for transmission of high-frequency electromagnetic wave signals. In order to utilize this characteristic, Non-Patent Document 1 discloses an inspection apparatus that measures the physical properties of an inspection object by on-chip (putting the inspection object on a transmission line). In the sensor chip of Non-Patent Document 1, a generation unit for generating terahertz waves, a microstrip line, and a detection unit for detecting terahertz waves are integrated on a glass substrate. Non-Patent Document 1 measures the attenuation of the intensity of the terahertz wave and the delay of the time waveform by the interaction between the leakage electromagnetic field and the water applied on the microstrip line. Here, the leakage electromagnetic field is an electromagnetic field generated when a terahertz wave propagating through the microstrip line leaks weakly from the microstrip line.
JP-A-8-320254 APL, 88,212511, 2006

The terahertz wave inspection system using the above-described sensor chip has the following problems because it is on-chip measurement.

First of all, it cannot be said that it is suitable for the purpose of measuring a large amount of inspection objects at high speed. For example, in screening tests for a wide variety of biomolecules and chemical substances, high speed and economic efficiency are required as well as accuracy. However, in the conventional system, man-hours are required for supplying samples and inserting / withdrawing chips into / from the inspection apparatus, so it is not easy to realize high-speed inspection.

In addition, in order to inspect a large amount of samples, the number of chips corresponding to the number of samples is required. However, in consideration of the fact that semiconductor crystals are generally used for generation and detection of terahertz waves, the number of chips increases. Along with this, the inspection cost is expected to increase.

An apparatus for adjusting the distance to the inspection object using the terahertz wave according to the present invention,
A sensor unit including a generation unit for generating a terahertz wave, a transmission line for propagating the terahertz wave, and a detection unit for detecting the terahertz wave propagating through the transmission line;
A delay unit for changing the detection timing of the detection unit;
A processing unit for obtaining information on a time waveform by sampling a signal detected by the detection unit, obtained using the delay unit;
A distance changing means for changing a distance between the sensor unit and the inspection object,
The distance is adjusted using information on the time waveform.

In addition, the method for adjusting the distance to the inspection object by the terahertz wave according to the present invention,
Generating a terahertz wave at a first distance between the transmission line and the inspection object for propagating the terahertz wave;
Detecting the terahertz wave generated at the first distance at the first distance;
Obtaining information regarding the time waveform of the terahertz wave detected at the first distance;
Moving the transmission line or inspection object to a second distance shorter than the first distance;
Generating a terahertz wave at the second distance;
Detecting the terahertz wave generated at the second distance at the second distance;
Obtaining information regarding the time waveform of the terahertz wave detected at the second distance;
Comparing the information about the time waveform acquired at the first and second distances;
From the presence or absence of a change in the comparison result of information on the time waveform, determining whether or not there is an interaction between the leakage electromagnetic field caused by the terahertz wave propagating through the transmission line and the inspection object,
It is characterized by having.

Further, in view of the above problems, the inspection apparatus of the present invention includes a sensor unit and a distance adjusting unit or a distance changing unit, and the interaction state between the terahertz wave propagating through the transmission line of the sensor unit and the inspection object is determined. Information on the inspection object is acquired based on the detection signal of the detection unit of the sensor unit to be reflected. Here, the sensor unit includes a terahertz wave generation unit, a transmission line, and a detection unit. The distance adjusting means adjusts the distance between the transmission line and the inspection object based on the detection signal of the detection unit that detects the terahertz wave emitted from the terahertz wave generation unit and propagated through the transmission line.

Further, in view of the above problems, the inspection method of the present invention includes a step of preparing a sensor including a terahertz wave generation unit, a transmission line, and a detection unit, an inspection object placement step, a coarse movement step, a distance recognition step, A distance setting step and a data acquisition step are included. Here, in the inspection object placement step, the inspection object is disposed at a position facing the transmission line of the sensor. In the coarse movement step, the distance between the transmission line and the inspection object is brought closer while monitoring the detection signal of the detection unit that detects the terahertz wave emitted from the terahertz wave generation unit and propagated through the transmission line. In the distance recognition step, the distance at which the leakage electromagnetic field from the transmission line and the surface of the inspection object start to interact is recognized from the change in the detection signal of the detection unit. In the distance setting step, after the distance is recognized, the distance between the transmission line and the inspection object is set to a target distance at which the leakage electromagnetic field and the inspection object interact. In the data acquisition step, the information on the inspection object is acquired based on the detection signal of the detection unit that reflects the state of interaction between the terahertz wave propagating through the transmission line and the inspection object in the state set to the target distance.

In addition, an apparatus for adjusting the distance to an inspection object using a terahertz wave according to another present invention,
A sensor unit including a generation unit for generating a terahertz wave, a transmission line for propagating the terahertz wave, and a detection unit for detecting the terahertz wave propagating through the transmission line;
A distance changing means for changing a distance between the sensor unit and the inspection object,
The distance is adjusted using information on the terahertz wave detected by the detection unit.

Further, a method for adjusting the distance to the inspection object by the terahertz wave according to another present invention,
Generating a terahertz wave at a first distance between the transmission line and the inspection object for propagating the terahertz wave;
Detecting the terahertz wave generated at the first distance at the first distance;
Obtaining information on the terahertz wave detected at the first distance;
Moving the transmission line or inspection object to a second distance shorter than the first distance;
Generating a terahertz wave at the second distance;
Detecting the terahertz wave generated at the second distance at the second distance;
Obtaining information about the terahertz wave detected at the second distance;
Comparing the information about the terahertz waves acquired at the first and second distances;
From the presence or absence of a comparison result of information on the terahertz wave, determining whether or not there is an interaction between the leakage electromagnetic field caused by the terahertz wave propagating through the transmission line and the inspection object;
It is characterized by having.

According to the distance adjusting device of the present invention, since the distance changing means or the distance adjusting means as described above is provided, the transmission line and the inspection up to the target distance where the leakage electromagnetic field of the transmission line and the test object sufficiently interact with each other. Things can be brought close together. For example, the propagation characteristic of the terahertz wave can be measured at a target distance, and information such as the physical properties of the test object can be acquired.

Further, according to the inspection method of the present invention, it is possible to recognize that the leakage electromagnetic field leaking weakly from the transmission line and the surface of the inspection object start interaction from the change in the detection signal of the detection unit. . Since the starting distance is generally known in advance, the relative distance between the transmission line and the inspection object can be generally recognized at this point. Furthermore, based on the change in the detection signal, the transmission line and the inspection object are brought close to the target distance where the leakage electromagnetic field and the inspection object have sufficient interaction, and the propagation characteristic of the terahertz wave is measured at that distance. In addition, information such as physical properties of the inspection object can be acquired. At this time, once the relative distance between the transmission line and the inspection object can be generally recognized, the distance between the transmission line and the inspection object can be easily reached to the target. It can be taken with certainty.

Embodiments of the present invention will be described with reference to the drawings. As described above, in this specification, an electromagnetic wave in a frequency band of 30 GHz to 30 THz is also referred to as a terahertz wave. In addition, this invention is not limited to the apparatus and method which concern on the following embodiment.

(apparatus)
An apparatus for adjusting a distance using a terahertz wave according to an embodiment of the present invention will be described with reference to FIG. First, reference numeral 901 denotes a generator for generating terahertz waves. For example, it is composed of a photoconductive film made of gallium arsenide (LT-GaAs) or indium gallium arsenide (InGaAs) grown at a low temperature. Here, the photoconductive film is a film that generates carriers when irradiated with light. Note that a semiconductor element having electromagnetic wave gain, such as a resonant tunneling diode or a Gunn diode, can also be used for the generation unit 901.

Next, reference numeral 902 denotes a transmission line through which the terahertz wave generated from the generating unit 901 propagates. As the transmission line 902, a microstrip line made of a material having electrical conductivity such as metal can be used. Reference numeral 903 denotes a detection unit for detecting a terahertz wave propagating through the transmission line 902. The detection unit 903 uses the photoconductive film. Note that a detection element such as a Schottky barrier diode can also be used for the detection unit 903. Here, reference numeral 904 denotes a sensor unit including a generation unit 901, a transmission line 902, and a detection unit 903.

Reference numeral 905 denotes a delay unit for changing (delaying) the timing detected by the detection unit 903. The delay unit 905 can be configured by means for changing the path of light irradiated to the generation unit 901 or the detection unit 903.

Here, as an example of the delay unit 905, a delay unit 1005 that optically delays will be described with reference to FIG. Reference numeral 1010 denotes a laser irradiation unit for irradiating the generation unit 901 and the detection unit 903 with laser (light). Reference numeral 1011 denotes a beam splitter for dividing the laser irradiated by the laser irradiation unit 1010. The laser beams split by the beam splitter 1011 are irradiated to the generation unit 901 and the detection unit 903, respectively. The laser irradiated on the generation unit 901 passes through the delay unit 1005. For the delay unit 1005, for example, a movable mirror is used.

The delay unit 905 may be configured to delay the time for the terahertz wave to reach the detection unit 903. In order to change the distance at which the terahertz wave propagates, it is also possible to change the irradiation position of the laser irradiating the generator 901. Further, in order to change the propagation speed of the terahertz wave, it is possible to change the refractive index of the propagation region.

Further, the delay unit 905 can be configured to be electrically delayed. For example, it is possible to adopt a configuration in which the time of an electric signal generated for mixing with a detected terahertz wave signal is delayed.

Reference numeral 906 denotes a processing unit for acquiring information related to a time waveform by sampling a signal detected by the detection unit 903, which is obtained using the delay unit 905. Sampling can be performed, for example, in the cycle of laser irradiation, but is not particularly limited.

Here, reference numeral 908 denotes an inspection object holding unit for holding the inspection object 907. The inspection object holding unit 908 can be a flat plate made of, for example, a polyethylene resin such as Teflon (registered trademark) or polyimide, a metal such as aluminum, or an inorganic material such as quartz or sapphire. In the case of an endoscope to be described later, this inspection object holding unit can be omitted. In order to easily adjust the distance to the inspection object, the inspection object holder may be provided or omitted depending on the characteristics of the inspection object. Further, reference numeral 909 denotes distance changing means (Z-axis stage) for changing the distance between the sensor unit 904 and the inspection object holding unit 908 or the inspection object 907. A piezoelectric element etc. can be used for the distance changing means. However, it is not limited to this. The distance is adjusted by operating the distance changing means 909 using information on the time waveform acquired by the processing unit 906.

Here, in order to adjust the distance, it is not essential to use information related to the time waveform, and information related to the terahertz wave detected by the detection unit may be used. Thereby, for example, the change in the amplitude can be known from the integral value at a certain time (Δt) of the signal detected by the detection unit. Further, by using information on the time waveform, it is possible to know a change in the phase of the terahertz wave.

As described above, the distance can be adjusted by the interaction between the leakage electromagnetic field caused by the terahertz wave propagating through the transmission line 902 and the test object 907. Here, the leakage electromagnetic field is an electromagnetic field generated when a terahertz wave propagating through the transmission line 902 leaks out of the transmission line 902 as described above.

The processing unit 906 preferably stores information on a pulse waveform in a state where the inspection object 907 and the leakage electromagnetic field do not interact with each other. Thereby, when the information regarding the time waveform is attenuated or delayed as compared with the information regarding the pulse waveform, it can be determined that the interaction occurs. Note that the storage unit 906 does not necessarily need to perform the storage, and a storage unit for storing the storage may be provided.

Moreover, it is preferable to have a memory | storage part for memorize | storing the information regarding the terahertz wave which the said detection part detected in the state which has not produced the test object and the said leakage electromagnetic field as reference information. Thereby, when the information regarding the terahertz wave detected by the detection unit changes from the reference information, it can be determined that the interaction occurs.

(XY stage)
It is preferable that the inspection object holding unit 908 has a moving unit (XY stage) for moving in a direction perpendicular to the direction of the distance changed by the distance changing unit. A stepping motor can be used for the moving part. When the moving unit moves the inspection object holding unit based on the strength of the leakage electromagnetic field, the following effects can be obtained. That is, even when the distances are the same, the strength of interaction between the leakage electromagnetic field and the inspection object 907 and the interacting region can be increased.

(Separate transmission line and inspection object)
Moreover, it is preferable that the transmission line and the inspection object are separated from each other (that is, the two are not in contact with each other) to cause the interaction. Accordingly, it is possible to prevent deterioration of the sensor unit 904 caused by contact between the sensor unit 904 and the inspection object 907. The cause of the deterioration is considered to be due to the quality change or breakage of the material of the components such as the transmission line 902 due to the inspection object 907. The deterioration causes problems such as a decrease in the intensity of the terahertz wave propagating through the transmission line 907 and a change in the intensity of the leakage electromagnetic field. In addition, this problem causes variations in inspection results. As described above, when the same sensor unit 904 is used a plurality of times, it is difficult to obtain measurement results with good reproducibility.

Here, as a countermeasure against the above-described deterioration, the sensor unit 904 is usually cleaned or replaced for each measurement. Therefore, it is a great burden in terms of cost. The semiconductor crystals used in the generation unit 901 and the detection unit 903 are expensive. In addition, since the work process is bulky for cleaning and replacement, the throughput of the inspection process is also a problem.

(Transmission line for inspection and distance adjustment)
Further, the sensor unit 904 is preferably configured to include transmission lines for inspection and distance adjustment. Here, the two transmission lines are a transmission line for transmitting an electromagnetic wave used for adjusting the distance and a transmission line for transmitting an electromagnetic wave used for inspection of an inspection object. Details will be described in Example 2 described later.

(Endoscope)
The sensor unit 904 can be provided at the tip of the endoscope probe. In this case, the sensor unit 904 includes a coarse movement part for changing the distance between the inspection object and the transmission line by coarse movement, and a fine movement part for changing the distance between the inspection object and the transmission line by fine movement. It is preferable to have a changing means. Further, the distance adjusting device is provided at the tip of the endoscope probe, and the inspection object can be inspected based on information on the terahertz wave detected by the detection unit. Details will be described in Example 3 to be described later.

(Operation)
Next, a method for adjusting the distance or inspecting the inspection object using the terahertz wave according to the present embodiment will be described. The method according to this embodiment includes the following steps.
First, a terahertz wave is generated at a first distance between the transmission line for the propagation of the terahertz wave and the inspection object. Here, the first distance is, for example, the distance (L> L ₀ ) between the transmission line 121 and the inspection object 102 in [a] of FIG.

Next, the terahertz wave generated at the first distance is detected at the first distance. Then, information on the time waveform of the terahertz wave detected at the first distance (for example, the time waveform of [a] in FIG. 5) is acquired. Here, as described above, it is not essential to acquire information related to the time waveform, and information related to the terahertz wave may be acquired. The information regarding the terahertz wave is preferably at least one of electromagnetic wave intensity, time waveform, amplitude, phase, and frequency spectrum acquired by Fourier transform. Further, the information regarding the time waveform is preferably at least one of a time waveform, a time waveform intensity, a time width of the time waveform, and a frequency spectrum obtained by Fourier transform.

Here, the transmission line or the inspection object is moved to a second distance shorter than the first distance. Here, the second distance is, for example, the distance (L ₀ ) between the transmission line 121 and the inspection object 102 in [b] of FIG. A terahertz wave is generated at this second distance. Then, the terahertz wave generated at the second distance is detected at the second distance. Further, information on the time waveform of the terahertz wave detected at the second distance (for example, the time waveform of [b] in FIG. 5) (or information on the terahertz wave. The same shall apply hereinafter) is acquired.

Next, information on the time waveforms acquired at the first and second distances is compared. Then, it is determined whether or not there is an interaction between the leakage electromagnetic field caused by the terahertz wave propagating through the transmission line and the inspection object, based on whether or not the comparison result of the information regarding the time waveform is changed. Here, when there is no interaction, it is preferable to move the transmission line or the inspection object to a third distance shorter than the second distance. For example, when the second distance is L> L _{0 as} in the case of the first distance, it is preferable that the movement is performed up to a third distance where L ₀ is satisfied. Thereby, it can measure in the state accompanied by the said interaction. That is, after adjusting the distance using the information related to the time waveform so that the leakage electromagnetic field caused by the terahertz wave propagating through the transmission line interacts with the test object 102, the information related to the time waveform is acquired and inspected. You can inspect things.

Information on the time waveform acquired at the first distance is preferably stored. Furthermore, it is preferable to use the stored information as a reference signal for comparing with information related to a time waveform acquired at a distance different from the first distance. Thereby, it can be determined whether it is a state with the said interaction.

Moreover, it is preferable to have the process of increasing the strength of the leakage electromagnetic field from the transmission line after adjusting the distance. This step is preferably performed before the step of inspecting the inspection object. In the step of increasing the strength of the leakage electromagnetic field from the transmission line, the first transmission line having a weak leakage electromagnetic field strength is changed to the second transmission line having a stronger leakage electromagnetic field strength than the first transmission line. It is preferable to switch. Thereby, the strength of the leakage electromagnetic field can be increased. In the step of increasing the strength of the leakage electromagnetic field from the transmission line, it is preferable to increase the strength of the generated terahertz wave. Thereby, the strength of the leakage electromagnetic field can be increased.

Hereinafter, specific examples of the present invention will be described.

(Example 1: Adjusting the distance using a leakage electromagnetic field)
A configuration example and an operation example of the distance adjustment device or method and the inspection device or method according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram illustrating a configuration of an inspection apparatus 100 according to the first embodiment of the present invention. FIG. 2 is a configuration diagram of the sensor chip 120 in the inspection apparatus that is Embodiment 1 of the present invention. FIG. 3 is a schematic configuration diagram of a portion of the inspection apparatus in which the vicinity of the sensor unit 101 and the inspection object 102 is enlarged.

FIG. 4 shows an analysis example of the distance between the transmission line and the test object and the change in the propagation characteristics of the terahertz wave in the microstrip line sensor chip with line widths of 2 μm and 10 μm. 5 shows the propagation characteristics (pulse waveform) of the terahertz wave measured by the signal detector 108 when the distance between the transmission line and the inspection object is set to three types of distances, and the inspection object 102 and the leakage electromagnetic wave at each distance. 4 is a diagram schematically illustrating a relationship with a boundary 140. FIG.

First, the configuration of the inspection apparatus 100 of the present embodiment will be described. The inspection apparatus 100 includes a sensor unit 101, an inspection object holding unit 103 for arranging the inspection object 102, a distance adjusting unit 110 for adjusting a distance between the inspection object 102 and the sensor unit 101, and a leakage electromagnetic field intensity adjusting unit 114. Etc. The distance adjusting means 110 is for adjusting the distance between the transmission line and the inspection object to a distance where the leakage electromagnetic field from the transmission line and the inspection object interact.

The configuration and operation of the sensor unit 101 will be described. A sensor chip 120 having a role of generating, transmitting, and detecting terahertz waves is mounted on the sensor unit 101. As shown in FIG. 2, the sensor chip 120 has a configuration in which a generation unit 132, a transmission line 121, a detection unit 133, a GND (ground) layer 128, a dielectric layer 125, a through electrode 130, and the like are integrated on a substrate 129. It has become. The sensor unit 101 is connected to the Z-axis stage 106 via the arm 115. The Z-axis stage 106 uses a precision stage that can perform coarse movement of μm order by a stepping motor and fine movement of nm order by a piezoelectric actuator, and is controlled by a Z-axis stage control unit 107.

The sensor chip 120 will be described. As shown in FIG. 2, the generation unit 132 includes a generation signal line 123, a generation semiconductor layer 126, a generation through electrode 130, a GND layer 128, and a GND through electrode 134a, and plays a role of generating terahertz waves. . The generation unit 132 is electrically connected to the generation power source 112 through the generation through electrode 130 and the GND through electrode 134a. The detection unit 133 includes a detection signal line 124, a detection semiconductor layer 127, a detection through electrode 131, a GND layer 128, and a GND through electrode 134b, and plays a role of detecting terahertz waves. The detection unit 133 is electrically connected to the signal detection unit 108 via the detection through electrode 131 and the GND through electrode 134b. By supplying the power for generation and detection from the back surface of the sensor chip 120 using the through electrode, the inspection object 102 and the sensor chip 120 are prevented from coming into contact with each other through the power supply means.

In the inspection apparatus of this embodiment, a microstrip line type transmission line 121 having a line width of 2 μm is used. The terahertz wave generated by the generator 132 is coupled to the transmission line 121 and propagates through the dielectric sandwiched between the upper electrode layer 122 and the GND layer 128. And it couple | bonds with the detection part 133 and is taken out by the signal detection part 108 as an electrical signal. The transmission line 121 is not limited to a microstrip line, and for example, a coplanar web guide type transmission line or the like may be used.

The constituent materials of the sensor chip 120 of this embodiment will be described. As the material of the substrate 129, synthetic quartz that transmits an optical pulse with a wavelength of 810 nm was used. The generation semiconductor layer 126 and the detection semiconductor layer 127 are low-temperature grown gallium arsenide layers having a thickness of 2 μm, and are transferred onto the substrate 129 by Au thermocompression bonding. Ti / Au layers (20 nm / 200 nm) were used for the upper electrode layer 122, the generation signal line 123, and the detection signal line 124 of the transmission line 121. As the GND layer 128, a Ti / Au / Ti layer (20 nm / 500 nm / 20 nm) was used. The GND layer 128 also serves as a bonding layer during thermocompression bonding. The dielectric layer 125 has a thickness of 3 μm, and BCB (benzocyclobutene), which has a proven record as a low-loss dielectric material in the terahertz band, was used. Further, Cu that is excellent in electrical conductivity and easy to embed is used for the generation through electrode 130, the GND through electrode 134a, the detection through electrode 131, and the GND through electrode 134b. Note that the above-described constituent materials are examples, and are not limited thereto.

Next, generation and detection of the terahertz wave according to the present embodiment will be described. In this inspection apparatus, a well-known optical switch system is adopted for generation and detection of terahertz waves. A femtosecond laser unit 113 (titanium-sapphire laser, wavelength 810 nm) emits a light pulse 118 for an optical gate, and generates a light pulse 118a for generation and a light pulse 118b for detection by a beam splitter (not shown). Branch. Of the branched light pulses, the generation light pulse 118a is applied to the generation unit 132 of the sensor unit 101, and the detection light pulse 118b is detected by the sensor unit 101 after passing through a delay optical system (not shown). The part 133 is irradiated.

A bias voltage is applied to a part of the generation semiconductor layer 126 sandwiched between the generation signal line 123 and the GND layer 128 by the generation power source 112. In this state, the light pulse 118a is irradiated to the portion to which the voltage of the generating semiconductor layer 126 is applied through a slit (not shown) provided in the GND layer 128. As a result, the generation semiconductor layer 126 is optically gated, and a terahertz wave is generated as the photocurrent is excited. The generated terahertz wave is coupled to the transmission line 121.

When the terahertz wave propagates through the transmission line 121, a small amount of electromagnetic field leaks from the transmission line 121. In this specification, such an electromagnetic field is referred to as a leakage electromagnetic field 140. FIG. 3 schematically shows an electromagnetic field generated in the microstrip line on the sensor chip 120 when the terahertz wave propagates along a direction perpendicular to the paper surface. The strength of the leakage electromagnetic field 140 is mainly determined by the constituent material, shape and structure of the transmission line, the strength of the terahertz wave signal, and the like. Therefore, if the surrounding state, environment, and atmosphere are substantially the same, determining the above parameters determines the strength of the leakage electromagnetic field from the transmission line and the region affected by the leakage electromagnetic field. When the inspection object 102 is in the vicinity of the transmission line 121, an interaction occurs between the leakage electromagnetic field 140 and the inspection object 102. Therefore, the propagation characteristic of the terahertz wave propagating through the transmission line 121 changes. The inspection apparatus or method of the present invention acquires information such as the physical properties of the inspection object 102 by using the change in the propagation characteristics.

The terahertz wave that has propagated through the transmission line 121 reaches the detection unit 133. In the detection unit 133, a bias voltage is applied to a part of the detection semiconductor layer 127 sandwiched between the detection signal line 124 and the GND layer 128 by the signal detection unit 108. Then, similarly to the generation unit, the light pulse 118b that has passed through the delay optical system is irradiated from the back surface of the substrate 129. By sampling the photocurrent generated in the optically gated semiconductor layer 127 for detection by the optical pulse 118b by the signal detection unit 108, the propagation characteristic of the terahertz wave is detected as an electric signal.

The generation and detection method of the terahertz wave is not limited to the above method. For example, a semiconductor element having an electromagnetic wave gain such as a resonant tunneling diode or a Gunn diode may be used for the generating part. Further, a method using a detection element such as a Schottky barrier diode in the detection unit may be used.

A configuration around the sensor unit 101 and the inspection object 102 will be described. As shown in FIG. 3, the inspection object 102 is arranged by the inspection object holding means 103 so as to face the transmission line 121 of the sensor unit 101 and at a distance from the transmission line 121. Here, the distance between the surface of the transmission line 121 and the surface of the inspection object 102 is defined as “L”. In the apparatus or method according to the present invention, the distance L is adjusted by the distance adjusting means 110 in accordance with the change in the terahertz wave detection signal detected by the signal detection unit 108. The test object 102 is, for example, a biomolecule, a drug, a polymer material, or the like. In this embodiment, DNA dissolved in a phosphate buffer solution is used. The inspection object 102 is usually arranged in a dry state with a predetermined thickness.

The inspection object holding means 103 is a flat plate made of a resin such as Teflon (registered trademark) or polyimide, a metal such as aluminum, or an inorganic material such as quartz or sapphire. In this embodiment, a polyethylene resin that is relatively inexpensive and easy to mold is used. The inspection object 102 is dropped on the inspection object holding means 103 by about several tens of nanoliters using a minute amount dropping device such as a micro injector. The inspection object holding means 103 is mechanically fixed to the XY stage 104, and its position is controlled in the XY plane by the XY stage control unit 105. As the X-Y stage 104, a precision stage that can be operated with an accuracy of the order of μm by a stepping motor was used. In order to improve inspection efficiency (throughput), a plurality of inspection objects 102 may be arranged on the inspection object holding means 103 (see FIG. 1). In this case, each inspection object 102 is sequentially arranged and inspected so as to face the transmission line 121 of the sensor unit 101.

The configurations of the distance adjusting unit 110 and the leakage electromagnetic field intensity adjusting unit 114 will be described. The distance adjusting unit 110 includes a signal detection unit 108, a signal recording unit 109, an arithmetic processing unit 111, a Z-axis stage 106, and a Z-axis stage control unit 107, which are connected as shown in FIG. The arithmetic processing unit 111 includes a comparison unit 116 and a determination unit 117. The inspection apparatus 100 of the present embodiment has a configuration in which the distance L between the surface of the transmission line 121 on the sensor unit 101 and the surface of the inspection object 102 can be adjusted according to the change in the detection signal from the sensor unit 101. Yes. In the present invention, the means for executing such adjustment is called distance adjusting means 110 or distance changing means.

In addition, a signal is transmitted from the arithmetic processing unit 111 to the generating power source 112 and the femtosecond laser 113 via the leakage electromagnetic field intensity adjusting unit 114.

The distance adjusting unit 110 adjusts the distance between the sensor chip 120 and the inspection object 102 according to the change in the detection signal from the sensor unit 101 by the following system.

The terahertz wave detected by the sensor unit 101 is sampled by the signal detection unit 108, and the detection signal is transmitted as a pulse waveform to the signal recording unit 109 and the comparison unit 116 of the arithmetic processing unit 111. The signal recording unit 109 plays a role of storing the detection signal and transmitting the reference signal to the comparison unit 116. Here, the reference signal is typically a propagation characteristic (pulse waveform) of the terahertz wave measured by the signal detection unit 108 in a state where the inspection object 102 and the leakage electromagnetic field 140 do not interact with each other. (See state [a] in FIG. 5).

When the inspection object 102 and the leakage electromagnetic field 140 have already interacted with each other, the reference signal may be a pulse waveform detected in a state before the distance L is changed. Even in this case, the inspection object 102 and the sensor chip 120 can be accurately adjusted to the target distance.

The comparison unit 116 compares the pulse waveform of the reference signal stored in the signal recording unit 109 with the pulse waveform of the detection signal transmitted from the signal detection unit 108. The determination unit 117 determines whether there is a significant difference in the comparison waveform, and transmits a signal to the Z-axis stage control unit 107 according to the determination result to move the Z-axis stage 106 in the Z-axis direction. Although the sensor unit side is moved here, the inspection object holding means side may be moved in the Z-axis direction. In short, it is only necessary that the distance between the surface of the transmission line 121 on the sensor unit 101 and the surface of the inspection object 102 is changed by relatively moving the sensor unit 101 and the inspection object 102 in the Z-axis direction.

Next, an inspection method of the inspection apparatus according to this embodiment provided with the distance adjustment unit 110 and the leakage electromagnetic field adjustment unit 114 will be described.

As in the state of [a] in FIG. 5, when the transmission line is sufficiently separated from the inspection object, that is, the distance at which the interaction between the leakage electromagnetic field 140 from the transmission line 121 and the inspection object 102 does not occur. In L, a pulse waveform [a] peculiar to the transmission line 121 is obtained. This is a reference signal in the present embodiment, and is determined by the configuration of the sensor chip 120 and the intensity of the terahertz wave. In the analysis result of FIG. 4, the reference signal corresponds to a pulse waveform when the distance L is 50 μm.

As described above, when the sensor unit 101 and the inspection object 102 are sufficiently separated from each other, the pulse waveform from the signal detection unit 108 is the same as the reference signal. It is transmitted to the control unit 107. Upon receiving the signal, the Z-axis stage control unit moves the Z-axis stage in a coarse movement step (for example, a step in the range of 1 mm to 1 μm), and again measures terahertz wave propagation characteristics in the sensor unit 101.

When the Z-axis stage 106 is moved while measuring the propagation characteristics of the terahertz wave, and the sensor chip 120 is moved closer to the inspection object 102, the pulse waveform with a slight amount of attenuation or delay compared to the reference signal is eventually obtained [b] Reach the distance you can get. As shown in the state of [b] in FIG. 5, this distance is a distance (distance L ₀ ) at which the leakage electromagnetic field 140 and the surface of the inspection object 102 start to interact. The distance L ₀ is the material of the transmission line, shape, structure, determined by the strength or the like of the terahertz wave signal, by detecting the distance L ₀ by the detection of the start of the interaction, Z-axis stage controller 107 of the inspection apparatus 100 Recognizes the relative distance between the surface of the inspection object 102 and the sensor chip 120. That is, the analysis result shows that in the sensor chip of the present embodiment, the change in the electric field strength and the phase delay are caused by bringing the distance L between the transmission line and the inspection object close to about 10 μm. Therefore, the Z-axis stage control unit 107 can recognize the relative distance between the surface of the inspection object 102 and the sensor chip 120. Figure 4 shows the change in electric field strength (peak electric field intensity) and phase delay (peak
position) starts to appear prominently at a distance of approximately 10 μm.

At this time, the arithmetic processing unit 111 determines that there is a significant difference between the pulse waveforms of the detection signal and the reference signal, and sends a signal to the Z-axis stage control unit 107. Thus, the control mode is switched to a mode in which the Z-axis stage 106 is operated with fine movement (for example, a step in the range of 1 μm to 10 nm).

Further, while measuring the propagation characteristics of the terahertz wave, the Z-axis stage 106 is operated to bring the sensor chip 120 and the inspection object 102 close to a distance L _m (for example, L = L _m = 1 μm, [c] in FIG. 5 See state). This distance is to Z-axis stage controller 107 after recognizing the distance L _0, the Z-axis stage 106 by an amount that is known to achieve traveling at fine motion mode.

At this time, a sufficiently strong interaction occurs between the inspection object 102 and the leakage electromagnetic field 140. In other words, the terahertz wave propagating through the transmission line 121 and the test object 102 are in a state of causing a strong interaction. Therefore, since the propagation characteristics of the terahertz wave propagating through the transmission line 121 change, a pulse waveform [c] in which strong attenuation and delay occur compared to the reference signal is obtained. From the analysis results, in the sensor chip of this example, in the region where the distance L is close to 10 μm or less, the electric field strength and the phase delay change almost exponentially with respect to the change of the distance L. Further, if the distance condition of this embodiment (L = L _m = 1 μm), it is possible to perform measurement while keeping the state of the transmission line and the inspection object in a non-contact state.

The inspection method includes a step of preparing a sensor including a terahertz wave generation unit, a transmission line, and a detection unit, an inspection object placement step, a coarse movement step, a distance recognition step, a distance setting step, and a data acquisition step. And. Here, in the inspection object arranging step, the inspection object 102 is disposed at a position facing the transmission line 121 of the sensor 120 so as to be separated from the transmission line. In the coarse movement step, the distance between the transmission line and the inspection object is brought close while monitoring the detection signal of the detection unit 133 that detects the terahertz wave emitted from the terahertz wave generation unit 132 and propagated through the transmission line 121. In the distance recognition step, the distance L _{0 at} which the leakage electromagnetic field 140 from the transmission line 121 starts to interact with the surface of the inspection object 102 is recognized from the change in the detection signal of the detection unit 133. In the distance setting step, after the distance recognition, the distance between the transmission line 121 and the inspection object 102 is set to a target distance where the leakage electromagnetic field and the inspection object interact. In the data acquisition step, information on the inspection object is obtained based on the detection signal of the detection unit 133 that reflects the state of interaction between the terahertz wave propagating through the transmission line 121 and the inspection object 102 in the state where the target distance is set. get.

The following operation may be added. That is, between the distance recognition step and the data acquisition step, a signal is sent from the arithmetic processing unit 111 to the leakage electromagnetic field strength adjusting means 114, and the bias voltage applied to the generation semiconductor layer 126 by the generation power source 112 is set. You may change from 5V to 20V. Further, a signal may be sent from the leakage electromagnetic field intensity adjusting means 114 to the femtosecond laser 113, and the optical output of the optical pulse 118 for optically gating the generating semiconductor layer 126 may be changed from 1 mW to 10 mW. At this time, since the signal intensity of the terahertz wave generated from the generation unit 132 increases, the intensity of the leakage electromagnetic field from the transmission line 121 further increases. As a result, the strength and area of interaction between the test object 102 and the leakage electromagnetic field 140 are effectively increased. In this state, the propagation characteristic of the terahertz wave is detected by the signal detection unit 108, and the physical property information of the inspection object is acquired. This leakage electromagnetic field increasing step can be executed, for example, after the distance recognition step or after the distance setting step.

According to the apparatus or method of the present embodiment, the distance adjustment unit 110 monitors the propagation characteristics of the terahertz wave propagating through the transmission line 121 of the sensor unit 101, and compares the detection signal with the reference signal, Bring the inspection object 102 closer. Then, the distance (L ₀ ) at which the electromagnetic field 140 leaking weakly from the surface of the transmission line 121 and the surface of the inspection object 102 starts to interact is recognized. That is, the relative distance between the sensor chip 120 and the inspection object 102 can be recognized from the change in the propagation characteristics of the terahertz wave. Further, the distance adjusting unit 110 is used to adjust the inspection object 102 and the sensor chip 120 from the distance L ₀ to a suitable distance that causes a sufficient interaction between the leakage electromagnetic field 140 and the inspection object 102. It is possible. Since the state between the transmission line and the inspection object can be uniquely determined by adjusting the distance between the transmission line and the inspection object in this way, measurement with good sensitivity and reproducibility is realized.

In addition, this inspection apparatus includes a leakage electromagnetic field strength adjusting means 114, and increases the strength of the leakage electromagnetic field from the transmission line while keeping the distance between the transmission line and the inspection object close to the distance at which the interaction occurs. It is also possible to make it. In this state, by acquiring the state of interaction between the leakage electromagnetic field from the transmission line and the test object as the propagation characteristic of the terahertz wave, information such as physical property data of the test object can be acquired with higher sensitivity.

Thus, according to the apparatus or method of the present embodiment, the state between the transmission line and the inspection object can be uniquely determined by adjusting the distance between the transmission line and the inspection object. Inspection with good reproducibility is realized. In addition, it is possible to perform measurement using a leakage electromagnetic field at high speed and low cost compared to on-chip measurement. Furthermore, terahertz wave measurement using a leakage electromagnetic field can be applied as an in-situ observation means such as a microscope. In addition, since the transmission line and the inspection object can be measured in a non-contact state, the frequency of sensor deterioration, cleaning and replacement is reduced, and more economical inspection is possible.

Here, in the conventional on-chip measurement, it is difficult to use the method of measuring the interaction with the leakage electromagnetic field for in-situ observation such as a microscope or in-situ measurement. The conventional on-chip measurement is, for example, the measurement disclosed in Non-Patent Document 1 (APL, 88, 212511, 2006). From the viewpoint of measurement sensitivity and reproducibility, it is important to uniquely determine the state of the observation object and the transmission line. Non-Patent Document 1 does not disclose or suggest the concept of the present invention for adjusting the distance.

In the present invention, as described above, the distance is adjusted using a leakage electromagnetic field. The present invention is different from that in which the distance is derived by obtaining the propagation time from when the terahertz wave is generated until the terahertz wave is reflected and detected by the inspection object.

(Example 2: Transmission line for inspection and distance adjustment)
FIG. 6 is a schematic configuration diagram showing a configuration of a distance adjustment device or method and an inspection device or method that are Embodiment 2 of the present invention. FIG. 7 is a configuration diagram of a sensor chip used in the distance adjustment apparatus or method and the inspection apparatus or method of this example.

The inspection apparatus 200 of this embodiment also includes a sensor unit 101, an inspection object holding unit 103 for arranging the inspection object 102, a distance adjustment unit 110 for adjusting the distance between the inspection object 102 and the sensor unit 101, and a leakage electromagnetic field intensity adjustment. Consists of means 114 and the like. In the present embodiment, unlike the first embodiment, the leakage electromagnetic field intensity adjusting means 114 is connected to an XY stage control unit 105 that moves and controls the XY stage 104 in the XY plane.

In this embodiment, as shown in FIG. 7, the sensor chip 220 includes a generation unit 132, an inspection transmission line 221, a distance adjustment transmission line 222, a detection unit 133, a GND layer 128, a dielectric layer 125, a through electrode 130, and the like. Is integrated on the substrate 129. The generation and detection of the terahertz wave employs an optical switch system as in the first embodiment. As in the first embodiment, microstrip line type transmission lines are used for the inspection transmission line 221 and the distance adjustment transmission line 222.

The inspection transmission line 221 is a microstrip line having a length of 300 μm and a line width of 2 μm, and is used for inspecting the inspection object 102. On the other hand, the distance adjusting transmission line 222 is a microstrip line having a length of 300 μm and a line width of 10 μm, and is used for adjusting the distance between the inspection object 102 and the sensor chip 220. The inspection transmission line 221 and the distance adjustment transmission line 222 are arranged in parallel at positions separated by 50 μm.

In general, the strength of the leakage electromagnetic field from the transmission line is determined by the constituent material, shape, structure, and strength of the terahertz wave signal of the transmission line. In the microstrip line, when the other structures are the same, the line with a narrower line width increases the strength of the leakage electromagnetic field and the leaked area. That is, when the distance L between the inspection object and the transmission line is the same, the terahertz wave propagating through the line having a narrow line width has a stronger interaction with the inspection object.

In the inspection apparatus of the present embodiment, first, the distance between the distance adjustment transmission line 222 and the inspection object 102 is adjusted by using the interaction between the leakage electromagnetic field from the distance adjustment transmission line 222 and the inspection object 102. . Similar to the first embodiment, the distance L is adjusted by the distance adjusting unit 110 to a distance at which the terahertz wave propagating through the distance adjusting transmission line 222 and the test object 102 interact with each other. Since the specific method is the same as that of the first embodiment, the description is omitted.

Here, a signal is sent from the distance adjusting unit 110 to the XY stage control unit 105 via the leakage electromagnetic field intensity adjusting unit 114, the XY stage 104 is moved by 50 μm in the horizontal direction, and the inspection site is the inspection transmission line 221. Arranged below. In the inspection transmission line 221 having a narrow line width, the strength and area of the interaction between the propagating terahertz wave and the inspection object 102 are effectively increased even at the same distance L. In this state, the propagation characteristic of the terahertz wave is detected by the signal detection unit 108, and information such as physical properties of the inspection object 102 is acquired. FIG. 4 shows how the change in electric field strength and the phase delay differ at the same distance L between the inspection transmission line 221 and the distance adjustment transmission line 222.

As the leakage electromagnetic field increasing step, both the method described in the first embodiment and the method described in the present embodiment can be performed. In the above example, two types of transmission lines are provided, but three or more types of transmission lines having different leakage electromagnetic fields may be provided. In this case, at least one is a distance adjustment transmission line and at least one is an inspection transmission line.

In this way, two or more types of transmission lines having different leakage electromagnetic field strengths are arranged, and the distance L is adjusted by the transmission line of the weak first leakage electromagnetic field, so that the second stronger than the first leakage electromagnetic field strength. Measure the propagation characteristics of terahertz waves on transmission lines with leakage electromagnetic field strength. As a result, more sensitive measurement is expected.

Also, as in Example 1, it is possible to uniquely determine the state between the transmission line and the inspection object by adjusting the distance between the transmission line and the inspection object, so that inspection with good measurement sensitivity and reproducibility is possible. Is realized. In addition, it is possible to perform measurement using a leakage electromagnetic field at high speed and low cost compared to on-chip measurement. Furthermore, terahertz wave measurement using a leakage electromagnetic field can be applied as an in-situ observation means such as a microscope. In addition, since measurement is possible even when the transmission line and the inspection object are not in contact with each other, the frequency of sensor deterioration, cleaning, and replacement is reduced, and more economical inspection is possible.

(Example 3: Endoscope)
FIG. 8 is a schematic configuration diagram showing an endoscope system using the inspection apparatus or method of the present invention which is the third embodiment of the present invention. Here, FIG. 8A is a configuration diagram of the present system, FIG. 8B is an enlarged cross-sectional view of the region A, and FIG. 8C is an example of the state of the sensor unit during measurement. In FIG. 8, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

A configuration of the endoscope system 300 of the present embodiment will be described. The endoscope system 300 includes an endoscope probe 320, a distance adjusting unit 310 that adjusts a distance between the inspection object 302 and the sensor unit 301, and each component described in the previous embodiment. The endoscope probe 320 includes a sensor unit 301, a flexible tube 321, a Z-axis coarse movement unit 328, a Z-axis fine movement unit 329, and the like.

The flexible tube 321 mainly includes a generation optical fiber 324, a detection optical fiber 325, a signal line 323, a Z-axis coarse movement portion 328, and the like, and a fine movement of nm order by a piezoelectric actuator is provided at the tip. A Z-axis fine movement portion 329 that can be used is disposed. Here, as the Z-axis coarse movement portion 328, a rotary microstage capable of performing coarse movement on the order of μm was used. In the rotary microstage, a cylindrical member having a fine female screw inner surface that is rotatably inserted into the flexible tube 321 is rotated, and a disk member having a fine screw outer surface is fixed. By moving in the axial direction of the tube 321, the sensor unit 301 is moved. FIG. 8 (b) shows a state in which the disk member to which the sensor chip 120 of the sensor unit 301 is fixed has been retracted inward, and FIG. 8 (c) shows a state in which the disk member has come out outward. Show.

The sensor unit 301 includes a sensor chip 120 (described in the first embodiment) disposed at the distal end of the endoscope 320. The sensor chip 120 is connected to the femtosecond laser unit 113 through the generation optical fiber 324 and the detection optical fiber 325, and is connected to the generation power source 112 and the signal detection unit 108 through the signal line 323. The surface of the sensor chip 120 is coated with an SOG (spin-on-glass) film serving as a protective film 330 with a thickness of about 50 nm to prevent the sensor portion from being deteriorated or damaged. Also in the present embodiment, as in the first embodiment, an optical switch system is employed for generation and detection of terahertz waves, and a microstrip line type transmission line is used for the inspection transmission line 121.

The endoscope system of the present embodiment operates as follows. In the present embodiment, a case where the endoscope probe 320 is inserted into the body and the inner wall surface of the internal organ is inspected will be described as an example. The operation of the sensor chip 120 is as described in the first embodiment.

First, the insertion of the endoscope probe 320, which is the first coarse movement step, brings the inner wall surface to be the inspection object 302 into contact with the tip of the endoscope probe 320. At this time, contact between the endoscope tip and the inspection object 302 is detected by a Z-axis fine movement unit 329 formed of a piezoelectric actuator located at the tip of the endoscope.

Next, as a second coarse movement step, the Z-axis coarse movement unit 328 is operated while measuring the propagation characteristic of the terahertz wave in the sensor unit 301 to bring the sensor chip 120 closer to the inspection object 102. When the distance L _{0 at} which the interaction that causes the change in the propagation characteristics of the terahertz wave is detected is detected, switching to the fine movement step is performed, and the Z-axis fine movement unit 329 is operated to bring the sensor chip 120 closer to the inspection object 102 to the target distance ( (See Figure 8 (c)). Detection of the detection unit 133 that reflects the state of interaction between the terahertz wave propagating through the transmission line 121 and the inspection object in a state adjusted to a suitable distance that causes sufficient interaction between the leakage electromagnetic field 140 and the inspection object Based on the signal, the physical property information of the inner wall of the body organ is acquired.

As described above, even when the measurement using the leakage electromagnetic field of the terahertz wave is used for the endoscope, the distance adjustment unit or the distance change unit, which is a feature of the present invention, is suitable for causing sufficient interaction. Measurement under distance conditions is possible. Thus, endoscopic examination with high sensitivity and good reproducibility is realized. Although only the inspection of the internal organs has been described in the present embodiment, the endoscope system of the present embodiment can naturally be used as, for example, an industrial endoscope for inspecting fine pipes and gaps.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram illustrating a configuration of a distance adjustment device or method and an inspection device or method according to a first embodiment. 1 is a configuration diagram of a sensor chip used in a distance adjustment device or method and an inspection device or method of Example 1. FIG. The schematic block diagram of the part which expanded the sensor part and the test object vicinity among distance adjustment apparatuses thru | or inspection apparatuses. The figure explaining the example of analysis of the relationship between the distance between a transmission line and a test object, and the propagation characteristic change of a terahertz wave. The figure which demonstrated typically the distance between a transmission line and a test object, and a propagation characteristic change. FIG. 3 is a schematic configuration diagram illustrating a configuration of a distance adjustment device or method and an inspection device or method according to a second embodiment. FIG. 3 is a configuration diagram of a sensor chip used in a distance adjustment device or method and an inspection device or method according to a second embodiment. FIG. 5 is a schematic configuration diagram illustrating an endoscope system according to a third embodiment. The schematic diagram for demonstrating the apparatus thru | or method which concerns on embodiment of this invention. The schematic diagram for demonstrating the apparatus thru | or method which concerns on embodiment of this invention.

Explanation of symbols

101, 904, sensor part (sensor)
102, 302, 907 Inspection object
103,908 Inspection object holding part (Inspection object holding means)
104 Moving part (XY stage)
108, 111, 906 Processor (signal detector, arithmetic processor)
109 Storage unit (signal recording unit)
110, 310, 909 Distance adjustment means (distance changing means)
121, 221, 222, 902 Transmission line
132,901 terahertz wave generator
133, 903 Sensor detector
905, 1005 delay section
108, 111, 906 Processor (signal detector, arithmetic processor)

Claims (12)

A distance adjustment device for adjusting a distance between the transmission line and an inspection object using the terahertz wave , including a transmission line for propagating the terahertz wave ,
A generator for generating a terahertz wave propagating through the transmission line ;
A detection unit for detecting a terahertz wave propagated through the transmission line,
A distance change means for varying exposed the distance in a direction intersecting the propagation direction of the terahertz wave in the transmission line,
A control unit for controlling the distance changing means ,
The terahertz wave propagating through the transmission line is configured to interact with the inspection object,
Wherein the control unit, the out of the terahertz wave detected by the detection unit, a distance adjusting device and controls the distance changing means using information on the terahertz waves at least said interaction. Wherein, among the terahertz wave detected by the detecting unit, by using a terahertz wave having an amplitude or phase that is at least the interaction distance according to claim 1, wherein the controller controls the distance changing means Adjustment device. Said interaction Keru Contact the absence Ji raw said distance, a storage unit for storing information about the terahertz wave detected by the detecting unit as the reference information,
Information about the terahertz wave detected by the detection unit, when the change from the reference information, according to claim 1 or 2, characterized in that and a determination unit for determining that the interaction occurs Distance adjustment device. The interaction is configured to be caused by a leakage electromagnetic field caused by a terahertz wave propagating through the transmission line and the inspection object,
The distance adjusting device according to claim 3, further comprising an adjusting unit configured to adjust the strength of the leakage electromagnetic field using a result of the determination unit. A delay unit for changing the timing of detecting the terahertz wave in the detection unit;
Wherein a terahertz wave signal detected by the detection unit, obtained using the delay unit, different from the plurality of signals said timing, be provided with a processing unit for obtaining information about the time waveform of the terahertz wave The distance adjusting device according to claim 1, wherein: Said transmission line includes a transmission line because the Ru used for the adjustment of the distance, any one of claims 1 to 5, characterized in that it consists of a transmission line of order to Ru used for the inspection of the inspection object 1 The distance adjusting device according to item. An inspection device for inspecting the inspection object, comprising the distance adjusting device according to any one of claims 1 to 6 ,
An inspection object holding unit for holding the inspection object;
An inspection apparatus , wherein the distance is determined using information on the terahertz wave, the interaction is performed at the determined distance, and the inspection object is inspected using information on the interacted terahertz wave . An inspection device for inspecting the inspection object, comprising the distance adjusting device according to any one of claims 1 to 6 ,
An inspection apparatus comprising an endoscope probe having the transmission line at a tip . An inspection method for inspecting an inspection object using the terahertz wave, including a transmission line for propagating the terahertz wave,
A first detection step of detecting a terahertz wave propagated through the transmission line at a first distance between the transmission line and the inspection object;
Regarding the direction intersecting the propagation direction of the terahertz wave in the transmission line, a changing step of changing the first distance to a second distance;
  A second detection step of detecting a terahertz wave propagated through the transmission line at the second distance;
Recognizing the distance between the transmission line and the inspection object using the terahertz waves detected in the first and second detection steps,
An inspection method characterized by causing a terahertz wave propagating through the transmission line to interact with the inspection object at a distance determined after the recognition, and inspecting the inspection object using the interacted terahertz wave . After the step of recognizing the distance between the transmission line and the inspection object, the step of bringing the distance between the transmission line and the inspection object closer to a third distance;
10. The inspection object according to claim 9, wherein at the third distance, the inspection object is inspected by acquiring information on an interaction between a leakage electromagnetic field caused by a terahertz wave propagating through the transmission line and the inspection object. Inspection method. The method includes an increasing step of increasing the strength of the leakage electromagnetic field from the transmission line before acquiring information on the interaction between the inspection object and the leakage electromagnetic field caused by the terahertz wave propagating through the transmission line. The inspection method according to claim 10. In the increasing step,
By switching the transmission line for propagating the terahertz wave from the first transmission line having a weak leakage electromagnetic field strength to the second transmission line having a stronger leakage electromagnetic field strength than the first transmission line, the leakage is caused. Increase the strength of the electromagnetic field, or
The inspection method according to claim 11, wherein the intensity of the leakage electromagnetic field is increased by increasing the intensity of the terahertz wave propagating through the transmission line.

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