JP2000238491A - Non-destructively inspecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-destructively inspecting apparatus for stably, accurately, highly sensitively, non-destructively simultaneously batch collecting static or dynamic elastic characteristics of a surface to be measured and an interior near the surface in one frame without contact structure-inspecting or dynamically or statically diagnosing a flaw or the like without influence to atmospheric fluctuation or surface irregularities to be measured. SOLUTION: A non-destructively inspecting apparatus comprises a transmitting optical system for emitting an excited optical beam 14a and a probe optical beam 24a to substantially the same positions to be measured, reversely plastically deforming a surface to be measured and an interior near the surface within an elastic limit and generating an elastic vibration on the surface to be measured and the interior near the surface, and a receiving optical system for heterodyne detecting the optical beam 4a reflected at the surface to be measured to strobe photographing static and dynamic holographic images as continuous strobe dynamic image to obtain static elastic characteristics and/or dynamic elastic characteristics of the surface to be measured or under the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nondestructive inspection technique, and more particularly to a method for diagnosing the strength of an object to be measured (particularly, a structure such as a highway or culvert, an outer wall of a building, etc., by directly contacting a probe. For structures that are difficult to measure, the static and dynamic elastic properties of the surface of the object to be measured and the interior of the surface are stable and high without being affected by atmospheric fluctuations or surface irregularities of the object to be measured. Non-contact and non-destructive simultaneous collection of one frame at a time with high accuracy and sensitivity, and dynamic inspection and structural inspection etc.
The present invention relates to a non-destructive inspection device for performing static diagnosis.

[0002]

2. Description of the Related Art Photoacoustic effects (Photoacousti)
c Effect is Tynd (1881)
all), Bell, X-ray (Rento)
gen) et al. That is, as shown in FIG. 3, when the intensity-modulated light (intermittent light) P19 is used as excitation light and condensed and irradiated on the sample P7 by the lens P5, heat is generated in the light absorption region (V _op ) P21. ,
The thermal diffusion region (V) given by the thermal diffusion length (μ _s ) P22
_th ) P23 is a phenomenon in which P23 is periodically diffused and an elastic wave (acoustic wave) is generated by the thermal strain wave. The sound wave, that is, the photoacoustic signal, is detected using a microphone (acousto-electrical transducer) or a piezoelectric element, or the periodic thermal expansion displacement generated on the sample surface is detected using an optical interferometer, and synchronized with the modulation frequency of the excitation light. By obtaining the obtained signal component, information on the surface and inside of the sample can be obtained. Thermal diffusion length ( _μs ) P2
2, the modulation frequency of the excitation light as f _E, the thermal conductivity of the sample P7 kappa, than the density [rho, and the specific heat c, is given by the following equation.

[0003] Regarding the method of detecting _{μ s = (κ / π ·} f E · ρ · c) 1/2 ... ( Equation 1) above photoacoustic signal, for example, the document "Non-destructive testing; Vol. 36, No. 10 , P.730-p.7.
36 (October 1987) "and the" IEE 1986 Ultra Sonics Symposium; p.
515-p. 526 (1986) (IEEE 1986)
ULTRASONICS Symposium; p.
515-p. 526 (1986)) "(first prior art).

The first prior art will be described with reference to FIG. The parallel light emitted from the laser P1 is intensity-modulated by an acousto-optic modulator (AO modulator) P2, and the intermittent light, that is, the excitation light is converted into a parallel light P19 having a desired beam diameter by a beam expander P3. The sample P is reflected by P4, and the sample P on the XY stage P6 is reflected by the lens P5.
Light is condensed on the surface 7. A sound wave is generated by the thermal strain wave generated from the light condensing portion P21 on the sample P7, and at the same time, a minute periodic thermal expansion displacement occurs on the surface of the sample P7. This minute displacement is detected by a Michelson interferometer described below. Laser P8
After the parallel light emitted from is expanded to a desired beam diameter by a beam expander P9, it is split into two optical paths by a half mirror P10, and one is condensed as probe light P24 at a position P21 on a sample P7 by a lens P5. Let it. The other irradiates the reference mirror P11. The reflected light from the sample P7 and the reflected light from the reference mirror P11 interfere with each other on the half mirror P10.
Is focused on a photoelectric conversion element P13 such as a photodiode. The photoelectrically converted interference intensity signal is a preamplifier P
After being amplified at 14, it is sent to the lock-in amplifier P16. In the lock-in amplifier P16, the acousto-optic modulator P
Using the modulation signal from the oscillator P15 used for the drive of No. 2 as a reference signal, only the modulation frequency component included in the interference intensity signal is extracted. This frequency component has information on the surface or inside of the sample P7 corresponding to the frequency. From equation (1), by changing the modulation frequency, the thermal diffusion length (μ _s ) P
22 can be changed, and information in the depth direction of the sample can be obtained. If there is an internal defect such as a crack in the thermal diffusion region (V _th ) P23, the thermal expansion displacement changes, and the amplitude of the modulation frequency component in the interference intensity signal and the phase with respect to the modulation frequency signal change. You can know. Movement signal of XY stage P6 and lock-in amplifier P
The output signal from 16 is processed by a computer P17, and a photoacoustic signal at each point on the sample is output as two-dimensional image information to a display P18 such as a monitor television.

[0005] However, the photoacoustic detection method of the first prior art is an effective means capable of detecting a photoacoustic signal in a non-contact and nondestructive manner. However, the optical path from the half mirror P10 to the sample P7 and the half mirror P10 When disturbance such as air fluctuation or vibration occurs between the optical paths reaching the reference mirror P11, the interference signal greatly fluctuates, and the S / N ratio (Signal to Noise Ratio) of the photoacoustic signal is reduced. There was a problem that it was greatly reduced.

As an optical interferometer for reducing the influence of such disturbance, a common optical path type interferometer shown in FIG. 4 is conceivable (second prior art). The excitation optical system in the second prior art is the same as the optical system shown in FIG. In the interferometer of the second prior art, after the parallel light emitted from the laser P8 is expanded to a desired beam diameter by the beam expander P9,
The light is reflected by a half mirror P39 via a lens P30, and is incident on a birefringent element P31 composed of calcite P31a, P31b and the like. In the birefringent element P31, the incident light has two polarization components P35 (solid line) and P36 orthogonal to each other.
(Broken line). With the lenses P32 and P5,
The polarized light component P35 is condensed at the same position P37 as the condensing point of the excitation light on the sample P7, and the polarized light component P36 is condensed at a position P38 slightly away therefrom. That is, the polarization component P35 is used as probe light, and the polarization component P36 is used as reference light. The probe light undergoes a phase change due to the thermal expansion displacement of the sample surface caused by the irradiation of the excitation light. Both reflected lights pass through the same optical path again, and then the birefringent element P3
1, and after passing through the half mirror P39, the photoelectric conversion element P1 such as a photodiode by a lens P12.
3 is collected. This combined light composed of polarization components orthogonal to each other causes polarization interference by the polarizing plate P33 provided in the optical path. The processing of the photoelectrically converted interference intensity signal is exactly the same as the optical system shown in the first prior art (FIG. 2).
Description is omitted.

[0007]

However, the photoacoustic detection method of the first prior art is an effective means capable of detecting a photoacoustic signal in a non-contact and nondestructive manner.
When a disturbance such as air fluctuation or vibration occurs between the optical path from 0 to the sample P7 and the optical path from the half mirror P10 to the reference mirror P11, the interference signal fluctuates greatly, and the S / N of the photoacoustic signal changes. (Signal / Noise) ratio had a problem that it dropped sharply.

On the other hand, in the photoacoustic detection method of the second prior art,
Since the probe light P35 and the reference light P36 pass through substantially the same optical path, they are less susceptible to disturbances such as air fluctuations and vibrations, and can be expected to have higher detection accuracy than the conventional method, but have the following problems. was there. First, sample P
7, the intensity modulation frequency f _E of the excitation light is lowered to obtain a thermal diffusion length (μ _s ) P22.
It is necessary to increase the thermal diffusion region (V t _{h) P23} given by, at this time, depending on the modulation frequency, as shown in FIG. 5, the thermal diffusion length (mu _s) P22, i.e. thermal expansion displacement occurs region results that may occur is larger case than the distance S between the reference light P36 and the probe light 35 with respect to thermal expansion displacement h to be detected originally, displacement and h _D actually detected There is a problem that the size of the photoacoustic signal is reduced and the detection sensitivity of the photoacoustic signal is reduced. In addition, it is possible to increase the interval S between the probe light P35 and the reference light P36 in accordance with the increase in the thermal diffusion length, but a new problem of lowering the spatial resolution occurs. Second, as shown in FIG. 6, the surface P40 of the sample P7
Has rough surfaces or minute irregularities, the reflected light of the probe light P35 and the reflected light of the reference light P36 are scattered, and coherence is reduced, making it difficult to accurately detect a phase change due to thermal expansion displacement. There was a problem of becoming. In addition, the photoacoustic detection methods of the first and second prior arts have the following problems in common. First, the sample P is moved while moving the XY stage P6.
7 surface P40 is two-dimensionally scanned with the probe light 35 to obtain a still image of one screen (diagnosis information of static elastic characteristics)
However, there is a problem that the optical resolution (spatial resolution) of a still image on one screen is about the beam diameter of the probe light P35. In particular, high-precision structural inspections, flaw detection, etc. are performed on objects to be measured (especially structures such as highways and culverts, and building outer walls, etc., where it is difficult to diagnose the strength by direct probe contact). -High resolution is required for non-contact / non-destructive execution with high sensitivity, but trade-off between high resolution of still image on one screen (diagnosis information of static elasticity) and frame creation time Therefore, if the beam diameter of the probe light 35 is reduced in response to the demand for high resolution,
As the number of pixels constituting a still image of a screen (diagnosis information of static elastic characteristics) increases at a rate of a square, the number of pixels constituting one still image (diagnosis information of static elastic characteristics) is required. There is a problem that a law state occurs in which the time increases at the rate of the square. For example, the number of pixels constituting a still image of one screen is 1000 ×
If the processing time of 1000 and 1 pixel is 10 μs, the frame creation time of a still image of one screen is about 10 seconds. When the beam diameter of the probe light 35 is reduced to half, a still image of one screen is formed. 2000x pixels
If the processing time of 2000 and one pixel is 10 μs, the frame creation time of a still image of one screen is quadrupled. As a result, the static elasticity characteristics (for example, vibration) of the size and depth of the internal defect (scratch), the growth possibility of the internal defect (scratch) (ie, whether or not the internal defect grows and grows in the future), etc. However, there is a problem that it is difficult to make a diagnosis of the steady-state characteristics of the mode in real time. Secondly, since the surface P40 of the sample P7 is two-dimensionally scanned with the probe light 35 while moving the XY stage P6 to create a still image (diagnosis information of static elasticity) of one screen, the absorption wavelength dependence and In order to obtain the spectral characteristics by sweeping the laser wavelength and the modulation frequency of the probe light 35 within a predetermined range in order to obtain the dependence on the thermal diffusion region, a still image (diagnosis information of static elastic characteristics) of one screen is considered. There is a problem that the frame creation time further increases. For example, when the laser wavelength is set to 10 points (not a sweep) under the above-described conditions, the number of pixels constituting a still image of one screen is 1000 × 1000.
Then, the frame creation time of a still image of one screen is 1
When the number of pixels constituting a still image of one screen is 2000 × 2000, the frame creation time of a still image of one screen is quadrupled (about 400 seconds). In this state, when the modulation frequency is set to 10 points (not a sweep), if the number of pixels constituting a still image of one screen is set to 1000 × 1000, the frame creation time of a still image of one screen is about 1000 seconds, and one screen is obtained. Assuming that the number of pixels constituting a still image is 2000 × 2000, the frame creation time of a still image of one screen is 4
Double (about 4000 seconds, how much a screen).
As a result, the dynamic elasticity characteristics (for example, vibration) of the size and depth of the internal defect (scratch) and the growth possibility of the internal defect (scratch) (that is, whether or not the internal defect grows in the future). There is a problem that it is difficult to diagnose in real time the mode characteristics, the spectral characteristics, the excitation wavelength dependence, the modulation frequency dependence, and the transient characteristics thereof.

An object of the present invention is to solve such a conventional problem. In particular, an object to be measured (particularly,
For structures where it is difficult to diagnose the strength etc. by directly contacting a probe, such as a highway or a ditch structure, or the outer wall of a building, etc.) , Dynamic, structural inspection, flaw detection, etc. by simultaneously collecting one frame of non-contact, non-destructive, stable, high accuracy, high sensitivity without being affected by atmospheric fluctuations or surface irregularities of the object to be measured -It is to provide a non-destructive inspection device that performs static diagnosis.

[0010]

The gist of the first aspect of the present invention is to provide a method for measuring static and internal characteristics of the surface of an object to be measured and the vicinity of the surface where it is difficult to directly contact the probe.
The dynamic elasticity is stable, high precision and high sensitivity without being affected by atmospheric fluctuations and surface irregularities of the object to be measured.
A non-destructive inspection device that collectively collects one frame at a time in a non-destructive manner and dynamically and statically diagnoses structural inspection, flaw detection, etc., and irradiates an excitation light beam and a probe light beam to substantially the same position of the measured object. Generating a photoacoustic signal corresponding to the excitation light beam inside the surface and near the surface of the object to be measured,
A perturbation is applied to the surface and the vicinity of the surface of the object to be measured by the photoacoustic signal, the surface and the vicinity of the surface are reversibly plastically deformed within the elastic limit, and an elastic vibration is generated in the surface and the vicinity of the surface. An optical system, receives the probe light beam reflected by the object to be measured, and optically continuously transmits the received probe light beam over the entire measurement surface irradiated with the received probe light beam; At the same time, optical heterodyne detection is performed at the same time to generate a static / dynamic holographic image as a continuous strobe moving image, and the beat frequency generated / output at the time of the optical heterodyne detection is used as the strobe frequency to obtain the static / dynamic The dynamic holographic image is shot with a strobe, and the measured The static elastic properties according to the evaluation of the elastic structural evaluation and testing results of the surface and subsurface of the subject and /
Alternatively, there is provided a nondestructive inspection apparatus having a receiving optical system for obtaining the dynamic elasticity characteristics. The gist of claim 2 of the present invention is that the static elasticity characteristic includes a steady-state characteristic of a vibration mode on the surface of the object to be measured and inside the vicinity of the surface. Exists in destructive inspection equipment. The gist of claim 3 of the present invention is that the dynamic elasticity property is a vibration mode property, a spectrum property, an excitation wavelength dependency, a modulation frequency dependency, or a vibration mode property on the surface of the object to be measured and inside the vicinity of the surface. The nondestructive inspection apparatus according to claim 1, wherein at least one of these transient characteristics is included. The gist of claim 4 of the present invention is that the state of the optical modulation superimposed on the probe light beam mainly due to the elastic vibration is a phase shift and / or a phase shift in the optical beat moving image signal.
Alternatively, the non-destructive inspection device according to claim 1 includes the beat frequency. The gist of claim 5 of the present invention is that the receiving optical system receives the probe light beam reflected by the object to be measured, and receives the probe light beam on the surface and inside the vicinity of the surface due to the elastic vibration. The optical beat moving image signal mainly superimposed on the probe light beam is detected by using optical mixing detection which is the optical heterodyne detection using the excitation light beam as a reference light, and the detected optical beat moving image signal is stroboscopically detected. An optical heterodyne interference optical system that generates and outputs the static / dynamic holographic image which is a continuous strobe moving image with a period and a degree of optical modulation as a holographic image, and the static / dynamic holographic image Generates and outputs photoelectric conversion signals by receiving light based on the strobe cycle, and visualizes the static and dynamic holographic images. Based on the image display system to be performed and the static / dynamic holographic image, the size or depth of the flaw / internal defect and / or the flaw / internal defect on the surface and inside the vicinity of the surface of the measured object Analysis of the static elastic properties and / or the dynamic elastic properties including growth potential
5. An analysis / diagnosis processing system which executes diagnosis in real time in synchronization with the strobe cycle of the static / dynamic holographic image (continuous strobe moving image). A non-destructive inspection apparatus according to one of the above aspects. The gist of claim 6 of the present invention is that the transmission optical system transmits a pump light having a predetermined first wavelength modulated at a predetermined first modulation frequency and / or a predetermined first pulse modulation factor. An excitation light transmitting optical system for collimating into a beam having a diameter and irradiating the surface of the object to be measured as a target, and pulse-modulated according to a predetermined second modulation frequency and / or a predetermined second pulse modulation degree. The probe light having the second wavelength λ ₂ is collimated into a beam having a second beam diameter to generate the probe light beam, and the probe is located at substantially the same position as the surface of the object to be irradiated with the excitation light beam. The non-destructive inspection apparatus according to any one of claims 2 to 5, further comprising a probe light transmission optical system that emits a light beam. The gist of claim 7 of the present invention is that the pumping light transmitting optical system generates and outputs pumping light having a predetermined wavelength and a predetermined power, and the pumping light generating unit generates and outputs the pumping light. A modulation process for modulating the pump light with the first modulation frequency at a predetermined pulse modulation factor and outputting the same, in synchronization with a predetermined first synchronization signal, a modulation process according to the first modulation frequency and the pulse modulation factor. A driving driver for generating and outputting a driving signal for performing the driving, and generating and outputting pumping light after performing modulation in accordance with the driving signal in synchronization with the first synchronization signal.
An excitation light phase modulation unit having an electro-optical element for outputting, and an excitation light after performing modulation according to a drive signal in synchronization with the first synchronization signal, according to an observation area on the object to be measured. An excitation light beam generating means for converting the excitation light beam, which is a parallel light having a beam cross section, into a predetermined surface, and a mirror for deflecting the excitation light beam collimated by the excitation light beam generation means to a predetermined surface. A non-destructive inspection apparatus according to claim 6. The gist of claim 8 of the present invention resides in that the first
7. The pulse modulation degree and the second pulse modulation degree of the probe light are set independently.
The non-destructive inspection device described in the above. The gist of claim 9 of the present invention is that the pumping light generating means sets at least one wavelength range of the pumping light from a near ultraviolet wavelength of about 200 nm to a far infrared wavelength range of about 100 μm as the first wavelength. The non-destructive inspection apparatus according to claim 6, wherein a plurality of types of excitation light lasers are provided. The gist of claim 10 of the present invention resides in that the probe light transmitting optical system is a probe light generating means which is a probe light laser for generating and outputting a probe light of the second wavelength and a predetermined power; The probe light generated and output by the light generation means is pulse-modulated at the second modulation frequency in accordance with the second pulse modulation degree and output, and the second modulation is performed in synchronization with the second synchronization signal. A driver for generating and outputting a drive signal for performing a modulation process according to a frequency and / or the second pulse modulation degree, and after performing a modulation according to the drive signal in synchronization with the second synchronization signal A probe light phase modulating means having an electro-optical element for generating and outputting the probe light; and a probe light after performing modulation in accordance with a drive signal in synchronization with the second synchronization signal, to the measurement object. upper A probe light beam generating means for converting the probe light beam into a parallel light beam having the second beam diameter corresponding to the measurement area and outputting the probe light beam, and bisecting the probe light beam emitted from the probe light beam generating means A probe light splitting means for providing the one of the two divided probe light beams as reference light to the optical heterodyne interference optical system and providing the other of the two divided probe light beams to a multiplexing means; Multiplexing means for superimposing the excitation light beam received from the mirror of the system and the probe light beam received from the probe light splitting means on the same optical axis and irradiating the observation area on the object to be measured. The non-destructive inspection device according to any one of claims 1 to 9, wherein: The gist of claim 11 of the present invention is that the probe light generating means sets at least one wavelength range of near-ultraviolet wavelength of about 200 nm to far-infrared wavelength range of about 100 μm as the second wavelength. The nondestructive inspection apparatus according to claim 10, further comprising at least one kind of laser for excitation light. Further, the gist of the twelfth aspect of the present invention is that the receiving optical system receives the energy of the excitation light beam and emits the light from the vicinity of a surface determined by a light absorption region and a thermal diffusion length of the measured object. The probe light beam modulated according to the photoacoustic signal is selected from laser light reflected from an observation area on the measured object and guided to the optical heterodyne interference optical system, and the optical heterodyne interference optical system is selected. Optical heterodyne detection is performed in a birefringent optical crystal provided in the optical fiber, and the optical beat moving image signal having the phase shift and the beat frequency having a two-dimensional distribution characteristic in the beam cross section of the probe light is optically mixed. The non-destructive inspection apparatus according to any one of claims 4 to 11, wherein the non-destructive inspection apparatus is configured to be generated by detection and applied to the image display system. The gist of claim 13 of the present invention is that a laser beam reflected from an observation area on the object to be measured is condensed by a lens, and the condensed laser beam is collimated by a collimator to select a subsequent wavelength. A light receiving means provided to the light receiving means, and at least the probe light beam modulated in accordance with the photoacoustic signal contained in the laser light received from the light receiving means is selected and provided to the optical heterodyne interference optical system at a subsequent stage. Wavelength selecting means, the probe light beam modulated according to the photoacoustic signal received from the wavelength selecting means and the probe light beam as the reference light, birefringent optical means having a predetermined Bragg diffraction angle Performing optical heterodyne detection by interfering in the phase shift and the phase shift having a two-dimensional distribution characteristic in the beam cross section of the probe light. 13. The optical heterodyne interference optical system which generates the optical beat moving image signal having a target frequency by optical heterodyne detection (optical mixed detection and optical beat detection) and provides the optical beat video signal to an image display system. The non-destructive inspection device described in the description. The gist of claim 14 of the present invention is that the optical heterodyne interference optical system constitutes a Michelson interference optical system together with an interference mirror, and the probe light beam modulated according to the photoacoustic signal transmits the wavelength of the probe light beam to the wavelength. The probe light beam received as the reference light from the probe light splitting means is received from the selection means, and the probe light beam modulated according to the photoacoustic signal and the probe light beam as the reference light are combined with each other. 14. The nondestructive inspection apparatus according to claim 13, wherein the optical mixing motion detection is performed by orthogonally and interfering with each other in the refraction optical means to output the optical beat moving image signal. The gist of the present invention resides in a non-destructive inspection device according to claim 14, wherein the birefringent optical means includes a birefringent optical crystal. The gist of claim 16 of the present invention resides in a nondestructive inspection apparatus according to claim 14, wherein the birefringent optical crystal includes an optical crystal of bismuth silicon oxide. The gist of claim 17 of the present invention is characterized in that the birefringent optical crystal includes a calcite optical crystal.
4. The non-destructive inspection device according to item 4. The gist of claim 18 of the present invention is that the analysis / diagnosis processing system samples the static / dynamic holographic image received from the image forming means in synchronization with a fourth synchronization signal, 18. A data collection means for generating and outputting data relating to the static / dynamic holographic image used for analyzing and diagnosing static elastic characteristics and / or the dynamic elastic characteristics. The non-destructive inspection device according to any one of the above.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the embodiment described below are that the object to be measured 60 (especially, the structure of a highway or culvert, the outer wall of a building, etc., is hardly diagnosed by directly contacting a probe with the probe, etc.). Elastic structure (e.g., steady-state vibration mode characteristics) and dynamic elastic characteristics (e.g., vibration mode characteristics, spectral characteristics, excitation Analysis and diagnosis of wavelength dependency, modulation frequency dependency, or their transient characteristics) are performed based on the phase shift Δψ having two-dimensional distribution characteristics in the beam cross section and the beat frequency Δf (= strobe frequency). Real-time and dynamic holographic images (continuous strobe animation)
Executes in a short time and collects one frame simultaneously in a stable, high-accuracy, high-sensitivity non-contact and non-destructive manner without being affected by fluctuations in the atmosphere or surface irregularities of the measured object 60 (for example, a strobe frequency of 30 Hz). Then 1/3 per frame
(0 seconds) and dynamically and statically diagnose structural inspections and flaw detection. In addition, the surface of the measured object 60, the light absorption region V _op and the thermal diffusion length μ _s (thermal diffusion region (V _th ))
Structure and scratches / internal defects 6 near the surface below the surface determined by
2 can be generated by in-situ observation visualized under real-time processing corresponding to the beat frequency Δf,
For visualization, existing commercially available image forming means can be used as it is. Particularly, in the case of static / dynamic holographic images for the scratches / internal defects 62, the growth potential of the scratches / internal defects 62 (that is, It is characterized in that it is possible to execute a diagnosis of whether or not the size becomes larger. As a result, instead of the conventional method of two-dimensionally scanning the laser beam within the measurement plane to synthesize a dot image, the optical beam is simultaneously and collectively formed in an optically continuous image form over the entire measurement plane. Processes static and dynamic holographic images (continuous strobe video) to beat frequency Δ
Since the flash photography (flash frequency = beat frequency Δf) is performed in real time according to f, the evaluation of the elastic structure and the flaw detection result on the surface and under the surface of the measured object 60 can be performed.
There is an effect that it can be realized by in-situ observation visualized in real time according to the beat frequency Δf. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an optical system diagram for explaining an embodiment of the nondestructive inspection apparatus according to the present invention. FIG.
The non-destructive inspection apparatus according to the present embodiment includes a structure to be measured 60 (particularly, a structure such as a highway or a ditch structure, or an outer wall of a building, etc., in which it is difficult to diagnose strength and the like by directly contacting a probe. Excitation light beam (parallel light) 14a
A transmission optical system for irradiating a probe light beam (parallel light) 24a, and a laser beam reflected by the measured object 60, and a static elastic characteristic (for example, on the surface of the measured object 60 and inside the vicinity of the surface) And a receiving optical system for obtaining dynamic elastic characteristics (for example, vibration mode characteristics, spectral characteristics, excitation wavelength dependence, modulation frequency dependence, or transient characteristics thereof).

The transmission optical system includes an excitation light transmission optical system and a probe light transmission optical system. The pumping light transmission optical system converts the pumping light (first wavelength λ ₁ ) that has been subjected to predetermined pulse modulation (first pulse modulation degree δ ₁ ) at a predetermined first modulation frequency f ₁ to a predetermined diameter (first beam diameter φ _1). ) Is an optical system that collimates into a beam and irradiates the surface of the target 60 to be measured, which is a target.
Excitation light phase modulation means (electro-optical element (EO), driving driver) 12, excitation light beam generation means (excitation light collimator) 14, mirror 16, timing control means (function generator) 44 ing. This makes it possible to perform structural inspection, flaw detection, and the like on the measurement target 60 (particularly, a structure such as a highway or culvert structure, or an outer wall of a building, or the like, which is difficult to diagnose with strength by directly contacting a probe). Can be executed with high resolution, high accuracy, high sensitivity, and without contact.

The first pulse modulation degree δ ₁ of the excitation light and the second pulse modulation degree δ ₂ of the probe light can be set independently. The first wavelength λ ₁ of the excitation light depends on the physical properties (mainly acoustic characteristics) of the measured object 60 at the first modulation frequency f ₁ , the light absorption length, the heat propagation region, and further, the state of the propagating atmosphere (fluctuation, The optimum wavelength is selected in consideration of the temperature, humidity, atmospheric pressure, etc., the surface state (roughness and minute unevenness) of the measurement target 60, the type and material of the inspection target, and the like. In other words, pulse modulated light (first pulse modulation degree δ ₁ , pump wavelength (first wavelength) λ ₁ , first modulation frequency f ₁ ) is used as the pump light, and the pump light is applied to the surface of the measured object 60 and the vicinity of the surface. Beam 1
A photoacoustic signal 64 corresponding to the optical beat moving signal 36a generated by the photoacoustic signal 64 corresponding to the elastic vibration from the surface of the measured object 60 and the vicinity of the surface (particularly, the scratches / internal defects 62) activated by the photoacoustic signal 64a. (Phase shift Δψ and beat frequency Δf (= strobe frequency)), the size and depth of the flaw / internal defect 62 and the growth potential of the flaw / internal defect 62 (that is, the feasibility of the flaw / internal defect 62 in the future) Dynamic elasticity (eg, vibration mode characteristic, spectral characteristic, excitation wavelength dependence, modulation frequency dependence) , Or their transient characteristics) can be analyzed and diagnosed in real time and in a short time using static and dynamic holographic images (continuous strobe moving images). . In other words, the measured object 6
A photoacoustic signal 64 corresponding to the excitation light beam 14a is generated on the surface and near the surface of the object 60.
The internal defect 62) is perturbed to reversibly plastically deform the surface and the interior near the surface (especially the scratch / internal defect 62) within the elastic limit.
The probe light beam 24a is mainly due to acoustic / elastic scattering phenomena such as burrian scattering and Rayleigh scattering and acoustic emission (AE) caused by elastic vibration (a kind of photoacoustic signal 66 including phonons) generated in the internal defect 62). The state of optical modulation such as Doppler shift that is considered to be superimposed (ie, optical beat moving image signal 36a
(Phase shift Δψ and beat frequency Δf (= strobe frequency)) are detected by optical heterodyne detection (optical mixing detection, optical beat detection), and the detected optical beat moving image signal 36a
Based on the degree of optical modulation of (phase shift Δψ and beat frequency Δf (= strobe frequency)), the size and depth of the flaw / internal defect 62 and the growth possibility of the flaw / internal defect 62 (that is, internal flaws in the future) Static elasticity (eg, steady state of vibration mode, etc.) and dynamic elasticity (eg, vibration mode characteristic,
Spectral characteristics, excitation wavelength dependence, modulation frequency dependence,
Or analysis and diagnosis of these transient characteristics, etc., using static and dynamic holographic images (continuous strobe video)
And can be executed in real time and in a short time. Further, the first pulse modulation factor δ ₁ , the excitation wavelength (first wavelength) λ ₁ , and the first modulation frequency f ₁ of the excitation light are determined by changing the physical properties (mainly acoustic characteristics), the light absorption length, and the heat propagation of the measured object 60. region,
In addition, the state can be freely changed in consideration of the state of the propagating atmosphere (fluctuation, temperature, humidity, pressure, etc.), the surface state (roughness or minute unevenness) of the measured object 60, and the type and material of the inspection object. In addition, diagnosis of static elastic characteristics such as the size and depth of the flaw / internal defect 62 and the growth direction of the flaw / internal defect 62 can be performed. Similarly, the probe light takes into account the state of the atmosphere (fluctuations, temperature, humidity, pressure, etc.) that propagates, the surface state (roughness and minute irregularities) of the measured object 60, the type and material of the inspection object, and the like. Since the second wavelength λ ₂ and the power P ₂ are optimized so as not to disturb the measurement field due to light, analysis of static elasticity and dynamic elasticity of the surface of the measured object 60 and the inside near the surface is performed. This makes it possible to remotely detect diagnostic information and static elastic characteristic diagnostic information with high resolution.

Referring to FIG. 1, the excitation light generating means 10
Is an excitation light laser that generates and outputs excitation light having a predetermined wavelength (first wavelength λ ₁ ) and predetermined power. In the present embodiment, since the wavelength range of the excitation light is a near ultraviolet wavelength range of about 200 nm to a far infrared wavelength range of about 100 μm, an excimer laser (wavelength of about 200 to 300 nm), a titanium-sapphire laser (wavelength of about 1060 nm), or the like is used. the solid-state laser, argon laser (wavelength 515 nm), CO ₂ laser (wavelength of about 10.6 nm), _CH 3 OH laser (wavelength of about 118 nm), gas laser such as HCN laser (wavelength of about 337 nm), and is constructed in combination with these A dye laser or the like is used. As a result, a photoacoustic signal 64 corresponding to the excitation light beam 14a is generated on the surface of the measured object 60 and inside the vicinity of the surface.
This causes a perturbation to the surface of the measured object 60 and the inside near the surface (especially the scratches / internal defects 62), and reversibly plastically deforms the surface and the inside near the surface (especially the scratches / internal defects 62) within the elastic limit. Acoustic and elastic scattering phenomena, such as burrian scattering and Rayleigh scattering, and acoustic emission (sometimes caused by elastic vibration (a type of photoacoustic signal 66 including phonons) generated on the surface and in the vicinity of the surface (especially, scratches / internal defects 62)) AE) can occur. As a result, the state of optical modulation such as Doppler shift which is considered to be superimposed on the probe light beam 24a mainly due to elastic vibration or AE (that is, the optical beat moving image signal 3
6a (phase shift Δψ and beat frequency Δf (= strobe frequency)) is detected by optical heterodyne detection (optical mixing detection, optical beat detection), and the detected optical beat moving image signal 36
a (phase shift Δψ and beat frequency Δf (= strobe frequency)) based on the degree of optical modulation, the size and depth of the flaw / internal defect 62, and the growth potential of the flaw / internal defect 62 (that is, Analysis and diagnosis of static and dynamic elastic properties (whether or not a defect grows and becomes larger) can be performed in real time and in a short time using static and dynamic holographic images (continuous strobe moving images). Become like

The excitation light phase modulating means (E / O and denoted in the figure) 12, a predetermined pulse modulation (first pulse excitation light at a first modulation frequency f ₁ to excitation light generation means 10 generates and outputs a and outputs running pulse modulation) in accordance with the degree of modulation [delta] _1), the first modulation frequency f ₁ and the first in synchronization with the first synchronizing signal 44a from the timing control means (function generator) 44 generating a driving driver generates and outputs a drive signal for performing modulation processing corresponding to the pulse modulation factor [delta] _1, the excitation light after the modulation in accordance with the drive signal in synchronization with the first synchronizing signal 44a -It has an output electro-optical element (EO). When the excitation light excitation light phase modulation means 12 for generating and outputting a _{E 1, E 1 = A 1} · exp {-i · δ 1 · sin (ω 1 · t + ψ 1)} represented by numerical formula (1) be able to. Here, A ₁ is amplitude, i is an imaginary operator, ω ₁ is angular frequency (= 2π · f ₁ ), t is time, ψ
₁ means phase.

The pumping light beam generating means (pumping light collimator) 14 modulates the pumping light E ₁ ｛δ ₁ , ω ₁ , ω ₁ , ω ₁ , ω ₁ , ω ₁ after performing modulation according to the drive signal in synchronization with the first synchronization signal 44 a.
{ ₁ } is determined according to the observation area on the object 60 to be measured (particularly, a structure such as a highway or culvert structure, an outer wall of a building, or the like, in which it is difficult to diagnose the strength by directly contacting a probe). An optical element for converting into a parallel light (excitation light beam 14a) having a beam cross-sectional area (first beam diameter φ ₁ ), which is configured around a collimator.

The mirror 16 combines the excitation light beam 14a (first modulation frequency f ₁ , first phase _{１ 1} , first beam diameter φ ₁ ) collimated by the excitation light beam generation means (excitation light collimator) 14. This is an optical element for deflecting the light to a predetermined surface of the wave means (combining beam splitter (BS)) 28.

The probe light transmitting optical system converts the probe light (second wavelength λ ₂ ) pulse-modulated according to the second pulse modulation factor δ ₂ at a predetermined second modulation frequency f ₂ into a predetermined diameter (second beam diameter). φ ₂ ) to generate a probe light beam 24 a (a second modulation frequency f ₂ , a second phase ψ ₂ , a second beam diameter φ ₂ ) and a pump light beam 1
4a (a first modulation frequency f ₁ , a first phase ψ ₁ , a first beam diameter φ ₁ ) is an optical system that irradiates the same position as the surface of the measurement target 60 irradiating the probe light generation means (probe light Laser) 20, probe light phase modulation means (electro-optical element (EO), driving driver) 22, probe light beam generating means (probe light collimator) 24, probe light splitting means (probe light beam splitter (B
S)) 26, multiplexing means (multiplexing beam splitter (B
S)), and a timing control means (function generator) 44 as a center.

As a result, the object to be measured 60 (particularly, a structure such as a highway or culvert structure, or an outer wall of a building, etc., for which it is difficult to diagnose the strength by directly contacting the probe).
In contrast, structural inspection, flaw detection, and the like can be performed with high resolution, high accuracy, high sensitivity, and without contact. That is, when the surface and the vicinity of the surface (particularly, the scratch / internal defect 62) are reversibly plastically deformed within the elastic limit, the elastic vibration (phonon) generated in the surface and the inside of the vicinity of the surface (particularly, the scratch / internal defect 62). Acoustic / elastic scattering phenomena, such as Brillouin scattering and Rayleigh scattering, and acoustic modulation (AE) caused by a photoacoustic signal 66a (a type of the photoacoustic signal 66 including a light-acoustic signal 66) including the optical beat moving image signal 36a (phase Probe means for remotely detecting the shift Δψ and the beat frequency Δf (= strobe frequency)) can be realized. As a result, the probe light beam 2
Based on the degree of optical modulation of the optical beat moving image signal 36a (the phase shift Δψ and the beat frequency Δf (= strobe frequency)) superimposed on 4a, the size of the flaw / internal defect 62, the existing depth, the flaw / internal defect 62 Static elastic characteristics (for example, steady-state characteristics of a vibration mode, etc.) and dynamic elastic characteristics (for example, vibration mode characteristics, spectral characteristics, etc.) Analysis and diagnosis of excitation wavelength dependence, modulation frequency dependence, or their transient characteristics, etc., can be performed in real time and in a short time using static and dynamic holographic images (continuous strobe moving images). . Also, the first pulse modulation degree δ of the excitation light E ₁ {δ ₁ , ω ₁ , t, { ₁ }
₁ , excitation wavelength (first wavelength) λ ₁ , first modulation frequency f
₁ is the physical properties (mainly acoustic properties) of the measured object 60, the light absorption length, the heat propagation area, and further the state of the propagating atmosphere (fluctuation, temperature, humidity, pressure, etc.), the surface of the measured object 60 It can be freely changed in consideration of the state (roughness and minute unevenness), the type and material of the inspection object, etc., so that the static elasticity such as the size and the existing depth of the scratch / internal defect 62, the growth direction of the scratch / internal defect 62, etc. Diagnosis of characteristics can be performed. Similarly,
The probe light takes into account the state of the atmosphere (fluctuation, temperature, humidity, pressure, etc.) that propagates, the surface state (roughness and minute irregularities) of the measured object 60, the type and material of the inspection object, and the like.
Since the second wavelength λ ₂ and the power P ₂ are optimized so as not to disturb the measurement field by the excitation light E ₁ {δ ₁ , ω ₁ , t, { ₁ }, the surface of the measured object 60 and the vicinity of the surface are optimized. This makes it possible to remotely detect, with high resolution, analysis / diagnosis information of static elastic characteristics and dynamic elastic characteristics of the inside and diagnostic information of static elastic characteristics. Also, there is no law between the resolution and the time required to compose one screen.

Referring to FIG. 1, the probe light generating means (probe light laser) 20 has a predetermined wavelength (second wavelength λ).
₂ ) A probe light laser that generates and outputs a probe light having a predetermined power. Probe light, atmospheric conditions propagating (fluctuation, temperature, humidity, atmospheric pressure, etc.), the surface state of the measurement target 60 (roughness and fine irregularities), with consideration of the type and material of the test object, the pumping light E ₁ ｛Δ ₁ , ω ₁ , t, ψ
It is optimized for the second wavelength lambda ₂ and power P ₂ so as not to disturb the measurement field by _1}. In this embodiment, 200n
Since the wavelength range of the probe light ranges from the near ultraviolet wavelength of about m to the far infrared wavelength of about 100 μm, solid-state lasers such as excimer laser (wavelength of about 200 to 300 nm) and titanium-sapphire laser (wavelength of about 1060 nm),
Argon laser (wavelength 515 nm), CO ₂ laser (wavelength about 10.6 nm), CH ₃ OH laser (wavelength 118
gas laser such as an HCN laser (wavelength of about 337 nm), and a dye laser configured in combination therewith.

The probe light phase modulating means (electro-optical element (EO), driving driver) 22 (denoted by E / O in the figure) is a probe light generating means (probe light laser) 2.
0 performs predetermined pulse modulation (pulse modulation corresponding to the second pulse modulation degree δ ₂ ) on the probe light generated and output by the second modulation frequency f ₂ , and outputs the probe light. a second synchronizing signal 44b in synchronism with a second modulation frequency f ₂ and a driver for driving for generating and outputting a drive signal for performing modulation processing corresponding to the second pulse modulation factor [delta] ₂ from the generator) 44, a An electro-optical element (EO) that generates and outputs probe light after performing modulation according to the drive signal in synchronization with the two synchronization signals 44b.

Excitation light E₁｛Δ₁, Ω₁, T, ψ₁第 No.
1 modulation frequency f₁And the second modulation frequency f of the probe light₂When
Can be set independently. Excitation light E₁｛Δ₁, Ω₁,
t, ψ₁The first pulse modulation degree δ of｝₁And second of probe light
Pulse modulation δ₂And can be set independently. Plow
The excitation light generated and output by the ₁
Then E₂= A₂・ Exp ｛-i ・ δ₂・ Sin (ω₂・ T + ψ₂)｝ (2nd formula). Where A₂Is the amplitude, i is the imaginary performance
Arithmetic, ω₂Is the angular frequency (= 2π · f₂), T is time, ψ
₂Means phase.

Probe light beam generating means (for probe light
The collimator 24 is driven in synchronization with the second synchronization signal 44b.
Probe light E after modulation according to the moving signal
₂｛Δ₂, Ω ₂, T, ψ₂｝ Is changed to the measurement target 60 (special
Highway and bridge structures, building exterior walls, etc.
Diagnosis of strength etc. is difficult by directly contacting the probe
Beam cross section (second view)
Beam diameter φ₂) (Probe light beam 24)
a) an optical element for converting into a)
It is configured.

Probe beam splitting means (probe beam
The splitter (BS) 26 is a probe light beam generator.
The probe emitted from the step (probe light collimator) 24
Light beam 24a (second modulation frequency f₂, The second phase
ψ₂, The second beam diameter φ₂) And 2 minutes
The other probe light beam (reference light) 24b (second modulation
Frequency f₂, The second phase ψ₂, The second beam diameter φ₂) To the light
The other probe given to the Telodyne interference optical system and divided into two
Light beam 24c (second modulation frequency f₂, The second phase ψ ₂,
Second beam diameter φ₂) To the multiplexing means (multiplexing beam splitter).
(BS) 28.

Multiplexing means (multiplexing beam splitter (B
S)) 28 is the excitation light beam received from the mirror 16
14a (first modulation frequency f₁, The first phase₁, The first bee
Diameter φ ₁) And probe beam splitting means (probe beam
Probe beam received from the splitter (BS) 26
24c (second modulation frequency f₂, The second phase ψ₂, Second
Beam diameter φ₂) On the same optical axis
It is an optical element for irradiating the observation area on 60.

The receiving optical system includes an excitation light beam 14a (first
Upon receiving the energy of the modulation frequency f ₁ , the first phase ψ ₁ , and the first beam diameter φ ₁ ), the light absorption region V _op of the measurement target 60 is received.
Probe light beam 24d (second modulation frequency f ₂ + Δ) modulated according to the photoacoustic signal 66 emitted from near the surface determined by the heat diffusion length μ _s and the heat diffusion region (V _th ).
f, the second phase ψ ₂ + Δψ) is selected from the laser light reflected from the observation area on the measured object 60 and guided to the optical heterodyne interference optical system, and the birefringence provided in the optical heterodyne interference optical system Optical heterodyne detection (detection also called optical mixing detection or optical beat detection) is performed in the optical crystal, and the two-dimensional distribution characteristics of the probe light E ₂ {δ ₂ , ω ₂ , t, { ₂ } in the beam cross section are performed. The optical beat moving image signal 36a having a phase shift Δψ and a beat frequency Δf (= strobe frequency) is generated by optical heterodyne detection (optical mixed detection, optical beat detection) and is given to an image display system. (Lens, collimator) 30,
A wavelength selecting means (spectroscope) 32, an optical heterodyne interference optical system, an image display system, and a diagnostic processing system are provided.

As a result, the measured object 60 (especially, high speed
For direct professional use such as road and bridge structures, building exterior walls, etc.
Structure that makes it difficult to diagnose strength etc. by contacting the probe)
High-resolution, high-precision, high-sensitivity
It can be executed in a non-contact and non-destructive manner. Sand
And the excitation light E₁｛Δ₁, Ω₁, T, ψ₁Pulse as パ ル ス
Modulated light (first pulse modulation degree δ₁, Excitation wavelength (first wavelength)
λ₁, The first modulation frequency f ₁), The measurement target 60
Light corresponding to the excitation light beam 14a on the surface and inside the vicinity of the surface
An acoustic signal 64 is generated, and the photoacoustic signal 64
The surface of the activated DUT 60 and the interior near the surface
(Especially the scratches / internal defects 62) by the optical heterogeneous
Optical signal obtained by Dyne detection (optical mixing detection, optical beat detection)
Signal 36a (phase shift Δ 位相 and beat frequency
Δf (= strobe frequency))
The size of the scratch / internal defect 62, the existing depth,
Growth potential of the local defect 62 (that is, internal defects
Static elastic properties (e.g.
Steady state vibration mode, etc.) and dynamic elasticity (eg,
Vibration mode characteristics, spectral characteristics, excitation wavelength dependence,
Tuning frequency dependence or their transient characteristics)
Analysis and diagnostics using static and dynamic holographic images
Runs in real time and in a short time using a continuous flash movie
become able to. In other words, the surface of the measured object 60
And photoacoustic corresponding to the excitation light beam 14a inside the vicinity of the surface
A signal 64 is generated, and the measured
The surface of the target 60 and the inside near the surface (particularly, scratches and internal defects)
62) to give a perturbation to the surface and the interior near the surface (especially
The internal defect 62) is reversibly plastically deformed within the elastic limit,
At this time, the surface and the inside near the surface (especially scratches / internal defects 6)
2) Elastic vibration (photoacoustic signal including phonon)
66 type), and Brillouin scattering and Rayleigh caused by
Acoustic and elastic scattering phenomena such as scattering and acoustic emission
Probe light E mainly due to the₂｛Δ₂,
ω₂, T, ψ₂Doppler thought to be superimposed on｝
The state of optical modulation such as shift (ie, optical beat movie
The signal 36a (the phase shift Δψ and the beat frequency Δf (=
Strobe frequency))) Optical heterodyne detection (optical mixing detection)
Wave, optical beat detection) and the detected optical beat video signal
No. 36a (phase shift Δψ and beat frequency Δf (=
Flaw based on the degree of optical modulation of the
The size of the internal defect 62, the existing depth, the scratch / internal defect 6
2 growth potential (that is, the growth of internal defects in the future
Solution of static elasticity and dynamic elasticity
Analysis and diagnostics using static and dynamic holographic images
Runs in real time and in a short time using a continuous flash movie
become able to. Also, the excitation light E₁｛Δ₁, Ω₁,
t, ψ₁The first pulse modulation degree δ of｝₁, Excitation wavelength (first wave
Length) λ₁, The first modulation frequency f₁Is the object to be measured 60
(Mainly acoustic characteristics), light absorption length, heat propagation area,
In addition, the state of the transmitting atmosphere (fluctuation, temperature, humidity, pressure
Etc.), the surface condition of the measurement target 60 (roughness and minute irregularities),
It can be changed freely considering the type and material of the inspection target
The size of the scratch / internal defect 62, the existing depth,
Diagnosis of static elastic characteristics such as the growth direction of the part defect 62 can be performed.
I will be able to. Similarly, the probe light E₂｛Δ₂,
ω₂, T, ψ₂｝ Indicates the state of the propagating atmosphere (fluctuation,
Temperature, humidity, air pressure, etc.), the surface condition of the measured object 60 (roughness)
Considering the type and material of the inspection object,
The excitation light E₁｛Δ₁, Ω₁, T, ψ₁Measurement by｝
Second wavelength λ that does not disturb the field₂And power P₂Optimized for
The surface of the measured object 60 and the vicinity of the surface
Analysis and diagnosis of static and dynamic elastic properties of parts
Remote detection of information and diagnostic information of static elasticity with high resolution
I will be able to.

That is, a phase shift Δψ having a two-dimensional distribution characteristic in a beam cross section and a beat frequency Δf (=
By providing a receiving optical system that generates a static / dynamic holographic image (continuous strobe moving image) based on the strobe frequency, the measured object 60 (particularly, the structure of a highway or a culvert, or the Analysis / diagnosis information of the static elasticity and dynamic elasticity of the surface of the measured object 60 and the inside of the vicinity of the surface of the object to be measured, such as a structure such as an outer wall, which is difficult to diagnose the strength by directly contacting the probe. And non-contact and non-destructive simultaneous collective collection of diagnostic information on static and elastic characteristics without affecting the fluctuations of the atmosphere or surface irregularities of the object 60 to be measured. (If the frequency is 30 Hz, 1/30 second per frame)
Diagnosis can be made statically.

Referring to FIG. 1, a light receiving means (lens, collimator) 30 is used for diagnosing strength or the like by directly contacting a probe with an object 60 to be measured (especially, a highway or culvert structure, an outer wall of a building, etc.). An optical element that collects laser light reflected from an observation area on a structure that is difficult to perform with a lens, collimates the collected laser light with a collimator, and provides the collimated laser light to a subsequent-stage wavelength selector (spectroscope) 32 It is. The laser beam reflected from the observation area on the measurement target 60 includes the excitation light beam 14a (first modulation frequency f ₁ ,
Phase ψ ₁ , first beam diameter φ ₁ ), excitation light beam 14 a
(First modulation frequency f ₁ , first phase ψ ₁ , first beam diameter φ
₁ ) Receiving the energy of ₁ ), it undergoes modulation in accordance with the photoacoustic signal 66 emitted from near the subsurface determined by the light absorption region _Vop , the thermal diffusion length _μs, and the thermal diffusion region ( _Vth ) of the measured object 60. Probe light beam 24d (second modulation frequency f ₂
+ Δf, the second phase ψ ₂ + Δψ).

The wavelength selecting means (spectroscope) 32 includes a probe light beam 24d (second modulation frequency f ₂ + Δf, second phase ψ ₂ + Δψ) included in the laser light received from the light receiving means (lens, collimator) 30. ) Is selected at least and given to the subsequent optical heterodyne interference optical system. As the wavelength selecting means (spectroscope) 32, a commercially available monochromator or the like can be used.

The optical heterodyne interference optical system includes a probe light beam 24 received from a wavelength selecting means (spectroscope) 32.
d (second modulation frequency f ₂ + Δf, second phase ψ ₂ + Δψ)
With the probe light beam (reference light) 24b (second modulation frequency f ₂ , second phase ψ ₂ , second beam diameter φ ₂ ) to perform optical heterodyne detection (detection also called optical mixing detection or optical beat detection). Execute, 2 in the beam cross section of the probe light
An optical beat moving image signal 36a having a phase shift Δψ having a dimensional distribution characteristic and a beat frequency Δf (= strobe frequency) is generated by optical heterodyne detection (optical mixing detection, optical beat detection) and is provided to an image display system. Yes, birefringent optical means (BSO) 36, mirror (M) 3
8. An interference mirror (M) 40 is provided.

That is, a phase shift Δψ having a two-dimensional distribution characteristic in a beam cross section and a beat frequency Δf (=
By providing an optical heterodyne interference optical system that generates a static / dynamic holographic image (continuous strobe moving image) based on the strobe frequency,
(Particularly, structures such as highways and culverts, and building outer walls, etc., which are difficult to diagnose by checking the strength by direct contact with the probe), the light absorption region _Vop, and the heat diffusion length μ _s
And dynamic holographic images (continuous strobe moving images) of the elastic structure and the scratches / internal defects 62 near the surface determined by the thermal diffusion region (V _th ) in real time according to the beat frequency Δf. = Beat frequency Δf). For visualization, an existing commercially available image forming means (CCD) 42 can be used as it is. In particular, with the static / dynamic holographic image of the flaw / internal defect 62, a diagnosis of the growth possibility of the flaw / internal defect 62 (that is, whether or not the internal defect grows and becomes large in the future) can be performed. As a result, static elastic characteristics (for example, steady-state characteristics of a vibration mode, etc.) and dynamic elastic characteristics (for example, vibration mode characteristics, spectral characteristics, excitation wavelength dependency, modulation, etc.) on the surface of the measured object 60 and inside the vicinity of the surface. Analysis / diagnosis information of frequency dependency or these transient characteristics) and diagnosis information of static elastic characteristics.
Simultaneous and simultaneous non-destructive, one-frame simultaneous collection with stable, high accuracy, and high sensitivity without being affected by atmospheric fluctuations or surface irregularities of the measured object 60 (for example, strobe frequency = 30H)
(If it is z, 1/30 second per frame), it is possible to dynamically and statically diagnose structural inspection, flaw detection and the like. As a result, instead of the conventional method of two-dimensionally scanning the laser beam within the measurement plane to synthesize a dot image, the optical beam is simultaneously and collectively formed in an optically continuous image form over the entire measurement plane. Since the static and dynamic holographic images (continuous strobe moving images) are subjected to strobe photographing (strobe frequency = beat frequency Δf) in real time according to the beat frequency Δf, the elasticity of the surface or under the surface of the measured object 60 is processed. The structure evaluation and the evaluation of the flaw detection result can be realized by in-situ observation visualized under real-time processing according to the beat frequency Δf.

Referring to FIG. 1, the birefringent optical means 36 comprises
Michelson interference optical system with interference mirror (M) 40
And the probe light beam 24d (the second modulation frequency f₂
+ Δf, second phase ψ₂+ Δψ) to the wavelength selection means (spectroscopy)
32) and a probe beam splitting means
(Beam splitter (BS) for probe light) 26
Lobe light beam (reference light) 24b (second modulation frequency
f₂, The second phase ψ₂, The second beam diameter φ₂)
Probe light beam 24d (second modulation frequency f₂+ Δf,
Second phase ψ₂+ Δψ) and probe light beam (reference light) 2
4b (second modulation frequency f ₂, The second phase ψ₂, Second beam
Diameter φ₂) Orthogonally interfere with each other,
Dyne detection (also known as optical mixing detection or optical beat detection)
(Wave) to mirror the optical beat video signal 36a (M)
38 is an optical element for outputting to the BSO (Bism
Uth Silicon Oxide) and calcite
Can be The birefringent optical means (BSO) 36
Lobe light beam 24d (second modulation frequency f₂+ Δf,
2 phase ψ₂+ Δψ) fixed to Bragg diffraction angle θ
Have been.

The mirror (M) 38 is provided with a birefringent optical means (B
The optical beat moving image signal 36a received from the SO) 36 is returned to the light receiving surface of the image forming means (CCD) 42. The interference mirror (M) 40 together with the birefringent optical means (BSO) 36 constitutes a (Michelson) interference optical system.

The probe beam splitting means (probe beam splitter (BS)) 26 transmits the birefringent optical means (BS).
O) 36, the probe light beam (reference light) 24b (the second modulation frequency f ₂ , the second
The phase ψ ₂ and the second beam diameter φ ₂ ) correspond to the birefringent optical means (B
After passing through the SO) 36, the light is emitted to the interference mirror (M) 40, and returns to the inside of the birefringent optical means (BSO) 36 again as reflected light reflected in the incident direction by the interference mirror (M) 40. In such an interference optical system, the probe light beam (reference light) 24b (second modulation frequency f ₂ , second phase ψ ₂ , second beam diameter φ ₂ ) and probe light beam 24d
The second modulation frequency f ₂ + Δf, the second phase ψ ₂ + Δψ) is subjected to optical heterodyne detection (optical mixing detection, optical beat detection) in the birefringent optical means (BSO) 36, so that the beat frequency Δf (= strobe frequency ) And the phase shift Δψ.

With such an optical heterodyne interference optical system, a disturbance superimposed on an optical path from the transmitting optical system to the receiving optical system via the surface of the measured object 60 (to a laser beam caused by air flow, aerosol, etc.). Effect) can be reduced.

The image display system uses a beat frequency Δf (==) obtained by optical heterodyne detection (optical mixing detection, optical beat detection).
Strobe frequency) to frame frequency (repetition frequency)
Static and dynamic holographic images with a phase shift Δψ as a luminance signal (continuous strobe video)
Image forming means (CCD) 4
2. An image display means (video monitor) 52 and a timing control means (function generator) 44 are provided.

The image forming means 42 outputs a third synchronizing signal 44c.
The optical beat moving image signal 36a obtained by optical heterodyne detection (optical mixing detection and optical beat detection) is received from the birefringent optical means (BSO) 36 in synchronization with
6a as a frame frequency (repetition frequency) and a phase shift Δψ of the optical beat moving image signal 36a obtained by optical heterodyne detection (optical mixing detection and optical beat detection) as a luminance signal. A photoelectric conversion element for converting the optical beat moving image signal 36a into a static / dynamic holographic image (moving image plane signal = video signal) and outputting the converted signal to an image display means (video monitor) 52. Element) A camera, a commercially available video camera, or the like can be used. As a result, instead of the conventional method of combining two-dimensional scanning of the laser beam within the measurement plane to synthesize a dot image, optical ensemble is simultaneously performed in the form of an optically continuous image over the entire measurement plane. Since a static / dynamic holographic image (continuous strobe moving image) is processed and strobe-photographed (strobe frequency = beat frequency Δf) in real time according to the beat frequency Δf, the elastic structure on the surface or under the surface of the measured object 60 is measured. The evaluation and the evaluation of the flaw detection result can be realized by in-situ observation visualized under real-time processing according to the beat frequency Δf.

That is, by synchronizing the beat frequency Δf (= strobe frequency) obtained by optical heterodyne detection (optical mixing detection, optical beat detection) with the frame frequency (normally about 30 Hz) of the image forming means (CCD) 42,
Static and dynamic holographic images (continuous strobe moving images) can be photographed and visualized by existing commercially available image forming means (CCD) 42. Image forming means (CCD)
The static / dynamic holographic image visualized at 42 is different from the conventional photoacoustic imaging method in which an image of one screen is created by two-dimensional scanning. Holographic image) can be generated. That is, an image (static / dynamic holographic image) having the number of screens corresponding to the frame frequency (= beat frequency Δf = strobe frequency, for example, 30 Hz) can be generated in one second. The surface, the light absorption region _Vop , the thermal diffusion length _μs, and the thermal diffusion region (V
_th ) determines a static / dynamic holographic image (continuous strobe moving image) of the elastic structure and the scratch / internal defect 62 near the surface below the surface in real time according to the frame frequency (= beat frequency Δf = strobe frequency, for example, 30 Hz). To enable flash photography (flash frequency = beat frequency Δf).

The image display means (video monitor) 52 is a monitor for displaying (visualizing) a static / dynamic holographic image (moving image plane signal = video signal), and an existing television monitor or the like can be used. .

The timing control means (function generator) 44 includes a first synchronizing signal 44a to be supplied to the driving driver of the excitation light phase modulating means 12 and a second synchronizing signal 44b to be supplied to the driving light of the probe light phase modulating means 22. A third synchronizing signal 44c to be given to the image forming means (CCD) 42, a data collecting means (lock-in amplifier) 50
To generate and output the fourth synchronizing signal 44d to be supplied to the first and second control signals, specifically, a function generator having a frequency synthesizing function is used. First
Synchronization signal 44a, second synchronization signal 44b, third synchronization signal 4
4c and the fourth synchronization signal 44d each have a predetermined phase relationship. The first synchronization signal 44a, the second synchronization signal 44b, the third synchronization signal 44c, and the fourth synchronization signal 4
The phase relationship between each of 4d can be arbitrarily changed. Further, the phase between the synchronization signals can be continuously changed. Thereby, static and dynamic holograms relating to the elastic structure and the scratches / internal defects 62 in the vicinity of the surface determined by the surface of the measured object 60, the light absorption region V _op , the thermal diffusion length _μs, and the thermal diffusion region (V _th ). A graphic image (continuous strobe moving image) can be strobe-photographed (strobe frequency = beat frequency Δf) in real time according to the beat frequency Δf. For visualization, an existing commercially available image forming means (CCD) 42 can be used as it is. In particular, with the static / dynamic holographic image of the flaw / internal defect 62, a diagnosis of the growth possibility of the flaw / internal defect 62 (that is, whether or not the internal defect grows and becomes large in the future) can be performed.

The analysis / diagnosis processing system includes image forming means (CC
D) Based on the static / dynamic holographic image (moving image plane signal = video signal) received from 42, the size and depth of the flaw / internal defect 62, and the growth potential of the flaw / internal defect 62 (ie, Static elastic characteristics (eg, steady state of vibration mode) and dynamic elastic characteristics (eg, vibration mode characteristics, spectral characteristics, excitation wavelength dependence, modulation, etc.) It is a processing device that executes analysis and diagnosis of frequency dependency or these transient characteristics, etc., based on in-situ observation visualized under real-time processing according to the beat frequency Δf, and displays the result. Computer (PC) 46, diagnostic display means (display (CR
T)) 48, data collection means (lock-in amplifier (Lo)
ck in Amp. )) 50.

The static elasticity characteristics are obtained by a static / dynamic holographic image in which various variables (parameters) of the excitation light beam 14a are specified, and in a state where various variables (parameters) of the probe light beam 24c are specified. It can analyze based on static and dynamic holographic images. In other words, the first pulse modulation factor [delta] ₁ and the excitation wavelength (first wavelength) lambda ₁ and the first modulation frequency f _1, etc. parameters of the excitation light beam 14a or the second modulation frequency f ₂ Ya of the probe light beam 24c, in a state of fixing the second phase [psi ₂ and parameters of the second beam diameter phi _2, etc., the static elastic properties of static and dynamic holographic image (optical beat video signal 36a of the frequency deviation Δf and phase shift Δψ , Etc.) can be obtained by analyzing the steady-state characteristics. For visualization, an existing commercially available image forming means (CCD) 42 can be used as it is.

The dynamic elasticity characteristics are calculated based on the relation between the static / dynamic holographic image and various parameters (parameters) of the excitation light beam 14a, and the relation between the static / dynamic holographic image and various parameters of the probe light beam 24c. Analyze based on relationships. In other words, the first pulse modulation degree δ ₁ of the excitation light beam 14 a, the excitation wavelength (first wavelength) λ ₁ , the first
The modulation frequency _{f 1} or the like of the variable (parameter), or a second modulation frequency _{f 2} and a second phase of the probe light beam 24c [psi
For ₂ and a second beam diameter phi _2, etc. variables (parameters), Ya dependency such as frequency deviation Δf and phase shift Δψ dynamic elastic properties (optical beat video signal 36a of static and dynamic holographic images (Transient characteristics). For example, the dynamic elastic properties of static and dynamic holographic image, the excitation light first pulse modulation factor [delta] ₁ and the excitation wavelength of the beam 14a (first wavelength) lambda ₁ and the first modulation frequency f ₁ and the like variables (parameter), or spectral properties include found by sweeping second modulation frequency f ₂ and a second phase [psi ₂ and the second beam diameter phi _2, etc. variables of the probe light beam 24c (parameter) in a predetermined range. Thereby, the surface of the measured object 60 and the light absorption region V
_The static / dynamic holographic image (continuous strobe moving image) of the elastic structure and the flaw / internal defect 62 near the surface determined by the _op , the thermal diffusion length _μs, and the thermal diffusion region (V _th ) according to the beat frequency Δf Flash photography (flash frequency = beat frequency Δf) can be performed in real time. For visualization, existing commercial image forming means (CC
D) 42 can be utilized as it is. In particular, scratches / internal defects 6
In the static and dynamic holographic images for 2,
Diagnosis of the possibility of growth of the scratch / internal defect 62 (that is, whether or not the internal defect grows and grows in the future) can be executed.
As a result, the size of the scratch / internal defect 62, the existing depth,
Dynamic elastic characteristics (for example, vibration mode characteristics, spectral characteristics, excitation wavelength dependence, modulation frequency dependence) with respect to the growth possibility of the scratch / internal defect 62 (that is, whether or not the internal defect grows and grows in the future). , Or their transient characteristics) can be diagnosed in real time according to the beat frequency Δf.

The data collecting means 50 is provided with an image forming means (C
CD) 42, a static / dynamic holographic image (moving image plane signal = video signal)
Generates and outputs static and dynamic holographic image data used for analysis and diagnosis of static elastic characteristics (for example, steady-state characteristics of vibration modes) and dynamic elastic characteristics by sampling in synchronization with d (reference signal) Specifically, a lock-in amplifier or a boxcar integrator can be used.

The diagnosing means 46 is a static / dynamic holographic image based on the static / dynamic holographic image data used for analyzing and diagnosing the static and dynamic elastic properties collected by the data collecting means 50. Static elastic characteristics of images (steady-state characteristics such as frequency deviation Δf and phase deviation Δψ of optical beat moving image signal 36a) and dynamic elastic characteristics of static / dynamic holographic images (frequency of optical beat moving image signal 36a) Analyzing the dependence and transient characteristics of the deviation Δf and the phase deviation Δψ, etc., and analyzing the size and depth of the flaw / internal defect 62 and the growth possibility of the flaw / internal defect 62 (that is, the possibility that the internal defect will grow in the future) The function of diagnosing whether or not it becomes larger) can be realized using a personal computer or the like.

The diagnostic display means 48 displays the diagnostic result from the diagnostic means 46, that is, the size and depth of the flaw / internal defect 62, the growth possibility of the flaw / internal defect 62 (ie,
This is a display device that displays a diagnosis result such as whether or not an internal defect grows and becomes large in the future). Specifically, a CRT display or a liquid crystal display can be used.

As described above, according to the present embodiment,
The excitation light E₁｛Δ₁, Ω₁, T, ψ ₁｝ (Excitation light bee
Pulse modulated light (first pulse modulation degree)
δ₁, Excitation wavelength (first wavelength) λ₁, The first modulation frequency
f₁) To be measured 60 (especially highways and culverts).
Direct probe contact with structures, building exterior walls, etc.
Surface of structures that are difficult to diagnose
Photoacoustic signal corresponding to the excitation light beam 14a inside the vicinity of the surface
64, which are activated by the photoacoustic signal 64.
The surface of the measured object 60 to be measured and the inside near the surface (particularly,
Elastic vibration from the internal defect 62) is detected by optical heterodyne detection.
Beat video signal obtained by (mixed optical detection, optical beat detection)
No. 36a (phase shift Δψ and beat frequency Δf (=
(Throbo frequency)
The size of the defect 62, the existing depth, the scratch / internal defect 62
Growth potential (ie, as internal defects grow in the future,
Or not) or other static elastic properties (for example,
Analysis and diagnosis of dynamic elastic properties
Dynamic holographic images (continuous strobe video)
And can be executed in real time and in a short time.

In other words, pulse modulated light (= excitation light beam 14a (first pulse modulation degree δ ₁ , excitation wavelength (first wavelength) λ ₁ ,
A photoacoustic signal 64 corresponding to the modulation frequency f ₁ )) is generated, and the photoacoustic signal 64 perturbs the surface of the object 60 to be measured and the inside of the surface (particularly, the flaw / internal defect 62), and the surface and the vicinity of the surface are measured. The inside (especially the scratches / internal defects 62) is reversibly plastically deformed within the elastic limit, and at this time, elastic vibrations (photoacoustic signals including phonons) generated on the surface and in the vicinity of the surface (especially the scratches / internal defects 62) 66, a probe light beam 24d (second modulation frequency f ₂ ) mainly due to acoustic / elastic scattering phenomena such as Brillouin scattering and Rayleigh scattering and acoustic emission (AE).
+ Δf, the state of an optical modulation such as a Doppler shift that is considered to be superimposed on the second phase ψ ₂ + Δψ) (ie,
The optical beat moving image signal 36a (phase shift Δψ and beat frequency Δf (= strobe frequency)) is detected, and the optical modulation of the detected optical beat moving image signal 36a (phase shift Δψ and beat frequency Δf (= strobe frequency)) is performed. Based on the degree, the size of the scratch / internal defect 62 and the existing depth,
Analysis and diagnosis of static elasticity and dynamic elasticity, such as the possibility of growth of the flaws / internal defects 62 (ie, whether or not the internal defects grow and grow in the future), are performed using static / dynamic holographic images. (Continuous strobe moving image) can be executed in real time and in a short time.

Further, the excitation light E ₁ １δ ₁ , ω ₁ , t,
The first pulse modulation degree δ ₁ , the excitation wavelength (first wavelength) λ ₁ , and the first modulation frequency f _{1 of} { ₁ } (the excitation light beam 14a)
The physical properties (mainly acoustic characteristics) of the measured object 60, the light absorption length, the heat propagation area, the state of the propagating atmosphere (fluctuation, temperature, humidity, atmospheric pressure, etc.), the surface state of the measured object 60 (Roughness and minute irregularities), the type and material of the inspection object, etc., can be freely changed, so that the static elasticity characteristics such as the size and depth of the flaw / internal defect 62 and the growth direction of the flaw / internal defect 62 Diagnosis can be performed.

Similarly, the probe light E ₂ ｛δ ₂ , ω ₂ ,
t, { ₂ } (probe light beam 24 a) is the state of the propagating atmosphere (fluctuation, temperature, humidity, pressure, etc.), the surface state of the measurement target 60 (roughness or minute irregularities), the type of the inspection target,
In consideration of the material, etc., the excitation light E ₁ ｛δ ₁ , ω ₁ ,
Since the second wavelength λ ₂ and the power P ₂ are optimized so as not to disturb the measurement field due to t, { ₁ } (excitation light beam 14 a), the static on the surface of the measured object 60 and the inside near the surface is static. It becomes possible to remotely detect the analysis / diagnosis information of the elastic characteristic and the dynamic elastic characteristic and the diagnostic information of the static elastic characteristic with high resolution.

It is to be noted that the present invention is not limited to the above embodiments, and each embodiment can be appropriately modified within the scope of the technical idea of the present invention. Further, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment,
The number, position, shape, and the like suitable for carrying out the present invention can be obtained. In each drawing, the same components are denoted by the same reference numerals.

[0054]

According to the nondestructive inspection apparatus of the present invention, it is difficult to diagnose the strength of the object to be measured (especially, the structure of a highway or a culvert, the outer wall of a building, etc., by directly contacting a probe. Static and dynamic elastic properties of the surface of the object to be measured and the interior near the surface,
Static and dynamic holographic images (continuous strobe video) based on phase shift and beat frequency (= strobe frequency) having two-dimensional distribution characteristics in the beam cross section
As a result, stable, high-precision, high-sensitivity non-contact
It is possible to collectively collect non-destructively one screen at the same time and to dynamically and statically diagnose structural inspection, flaw detection, and the like.

[Brief description of the drawings]

FIG. 1 is an optical system diagram for explaining an embodiment of a nondestructive inspection apparatus according to the present invention.

FIG. 2 is a diagram of a photoacoustic detection optical system for describing a photoacoustic detection method according to a first related art.

FIG. 3 is a cross-sectional view of a sample near the surface for explaining the principle of the photoacoustic effect.

FIG. 4 is a photoacoustic detection optical system diagram for explaining a photoacoustic detection method of a second related art using a common optical path interferometer.

FIG. 5 is a cross-sectional view of a sample near the surface for explaining how the detection sensitivity for thermal expansion displacement decreases due to an increase in thermal diffusion length in the common optical path interferometer of FIG.

FIG. 6 is a cross-sectional view of the sample near the surface in the common optical path interferometer of FIG. 4 for explaining how the coherence of the probe light and the reference light is reduced due to roughness and minute irregularities on the sample surface.

[Explanation of symbols]

Reference Signs List 10 excitation light generation means (excitation light laser) 12 excitation light phase modulation means (electro-optical element, driver) 14 excitation light beam generation means (excitation light collimator) 14a excitation light beam (parallel light) 16 ... Mirror 20 ... Probe light generating means (probe light laser) 22 ... Probe light phase modulation means (electro-optical element, driving driver) 24 ... Probe light beam generating means (probe light collimator) 24a ... Probe light Beam (parallel light) 24b ... Probe light beam (reference light) 26 ... Probe light splitting means (beam splitter for probe light) 28 ... Combining means (beam splitter for multiplexing) 30 ... Light receiving means (lens, collimator) 32 ... Wavelength selecting means (spectroscope) 36 Birefringent optical means (BSO) 36a Optical moving picture signal 38 Mirror 40 Interference 42: Image forming means (CCD) 44: Timing control means (function generator) 44a: First synchronization signal 44b: Second synchronization signal 44c: Third synchronization signal 44d: Fourth synchronization signal 46: Diagnosis means (personal computer) 48 diagnostic display means (display) 50 data collection means (lock-in amplifier) 52 image display means (video monitor) θ Bragg diffraction angle 60 subject to be measured 62 scratch / internal defect 64 photoacoustic signal, acoustic Emission

Claims (18)

[Claims] 1. The static and dynamic elastic characteristics of the surface of a measured object and the vicinity of the surface where it is difficult to directly contact the probe are affected by fluctuations in the atmosphere and surface irregularities of the measured object. A non-destructive inspection device that collects one frame at a time in a stable, high-accuracy, high-sensitivity, non-contact, non-destructive, and dynamically and statically diagnoses structural inspection and flaw detection, etc. The same position is irradiated with an excitation light beam and a probe light beam to generate a photoacoustic signal corresponding to the excitation light beam on the surface of the object to be measured and inside the vicinity of the surface, and the surface of the object to be measured is generated by the photoacoustic signal. And a perturbation inside the vicinity of the surface, reversibly plastically deform the surface and inside the vicinity of the surface within the elastic limit, and a transmission optical system that generates an elastic vibration on the surface and inside the vicinity of the surface, and is reflected by the object to be measured. hand The probe light beam is received, and the received probe light beam is collectively and simultaneously subjected to optical heterodyne detection in an optically continuous image form over the entire measurement surface irradiated with the received probe light beam. To generate a static / dynamic holographic image as a continuous strobe moving image, strobe-photograph the static / dynamic holographic image using the beat frequency generated / output during the optical heterodyne detection as the strobe frequency, and Optical system for obtaining the static elasticity property and / or the dynamic elasticity property related to the evaluation of the elastic structure or the flaw detection result on the surface or under the surface of the object to be measured based on information of a dynamic / dynamic holographic image And a non-destructive inspection device. 2. The non-destructive inspection apparatus according to claim 1, wherein the static elasticity characteristic includes a steady-state characteristic of a vibration mode on the surface of the object to be measured and inside the vicinity of the surface. 3. The dynamic elastic characteristic is at least one of a vibration mode characteristic, a spectral characteristic, an excitation wavelength dependence, a modulation frequency dependence, and a transient characteristic of the surface of the object to be measured and the vicinity of the surface. The non-destructive inspection device according to claim 1, comprising: 4. The optical modulation state superimposed on the probe light beam mainly due to the elastic vibration includes a phase shift in the optical beat moving image signal and / or the beat frequency. 2. The nondestructive inspection device according to 1. 5. The receiving optical system receives the probe light beam reflected by the measured object, and generates the probe light beam mainly due to the elastic vibration generated inside the surface and the vicinity of the surface. The optical beat moving image signal to be superimposed is detected using optical mixing detection which is the optical heterodyne detection using the excitation light beam as the reference light, and the detected optical beat moving image signal is used as a strobe period to determine the degree of optical modulation. An optical heterodyne interference optical system that generates and outputs the static / dynamic holographic image that is a continuous strobe moving image to be a holographic image, and receives the static / dynamic holographic image based on the strobe cycle. An image display system that generates and outputs a photoelectric conversion signal and visualizes the static / dynamic holographic image; Based on static and dynamic holographic images,
The static elasticity properties and / or the size or depth of the flaws / internal defects and / or the growth potential of flaws / internal defects on the surface and inside the vicinity of the surface of the object to be measured.
Alternatively, there is provided an analysis / diagnosis processing system which executes analysis / diagnosis of the dynamic elastic characteristic in real time in synchronization with the strobe cycle of the static / dynamic holographic image (continuous strobe moving image). The non-destructive inspection device according to claim 2. 6. The transmission optical system collimates an excitation light having a predetermined first wavelength modulated at a predetermined first modulation frequency and / or a predetermined first pulse modulation degree into a beam having a predetermined diameter. An excitation light transmitting optical system for irradiating a surface of the target to be measured with a target; and a probe light having a second wavelength pulse-modulated according to a predetermined second modulation frequency and / or a predetermined second pulse modulation degree. A probe light transmission optical system for generating the probe light beam by collimating into a beam shape having a second beam diameter, and irradiating the probe light beam at substantially the same position as the surface of the measured object to which the excitation light beam is irradiated The nondestructive inspection apparatus according to claim 2, further comprising: 7. The pumping light transmitting optical system includes: a pumping light generating unit that generates and outputs a pumping light having a predetermined wavelength and a predetermined power; and a pumping light that the pumping light generating unit generates and outputs.
A drive signal for outputting a signal modulated by a predetermined pulse modulation factor at a modulation frequency and performing a modulation process according to the first modulation frequency and the pulse modulation factor in synchronization with a predetermined first synchronization signal; A driving driver for generating / outputting an excitation light; and a phase modulation unit for excitation light including an electro-optical element for generating / outputting excitation light after performing modulation according to the drive signal in synchronization with the first synchronization signal. The excitation light after performing the modulation according to the drive signal in synchronization with the first synchronization signal is converted into the excitation light beam that is a parallel light having a beam cross-sectional area corresponding to an observation area on the measured object. The non-destructive inspection apparatus according to claim 6, further comprising: an excitation light beam generating unit that converts the light; and a mirror that deflects the excitation light beam collimated by the excitation light beam generation unit to a predetermined surface. 8. The nondestructive inspection apparatus according to claim 6, wherein the first pulse modulation degree of the excitation light and the second pulse modulation degree of the probe light are set independently. . 9. The pumping light generating means according to claim 1, wherein said first wavelength is at least one wavelength range of a near ultraviolet wavelength of about 200 nm to a far infrared wavelength range of about 100 μm.
7. The nondestructive inspection apparatus according to claim 6, further comprising at least two types of lasers for excitation light. 10. The probe light transmission optical system, wherein the probe light generation means is a probe light laser for generating and outputting the probe light of the second wavelength and predetermined power, and the probe light generation means generates and outputs the probe light. The probe light is pulse-modulated at the second modulation frequency in accordance with the second pulse modulation degree, and is output. The second modulation frequency and / or the second pulse are synchronized with the second synchronization signal. A driver for generating and outputting a drive signal for performing a modulation process in accordance with a modulation factor; and generating and outputting a probe light after performing a modulation in accordance with the drive signal in synchronization with the second synchronization signal. A probe light phase modulation unit having an electro-optical element, and the probe light after performing a modulation according to a drive signal in synchronization with the second synchronization signal, the probe light corresponding to an observation area on the measurement target. A probe light beam generating means for converting into the probe light beam which is a parallel light having a second beam diameter and outputting the probe light beam; and dividing the probe light beam emitted from the probe light beam generating means into two parts, A probe light splitting means for providing one of the probe light beams as reference light to the optical heterodyne interference optical system, and providing the other half of the probe light beam to the multiplexing means; Multiplexing means for superimposing the excitation light beam and the probe light beam received from the probe light dividing means on the same optical axis and irradiating the observation light on the observation area on the object to be measured. The nondestructive inspection device according to any one of claims 1 to 9. 11. The probe light generating means according to claim 2, wherein
Near UV wavelength of about 200 nm to 100 μm as wavelength
The nondestructive inspection apparatus according to claim 10, further comprising at least one kind of laser for excitation light having a wavelength range of the excitation light in a far-infrared wavelength region of a degree. 12. The receiving optical system receives the energy of the excitation light beam and modulates the light according to the photoacoustic signal emitted from the vicinity of a surface determined by a light absorption region and a thermal diffusion length of the object to be measured. The probe light beam received is selected from laser light reflected from an observation area on the object to be measured and guided to the optical heterodyne interference optical system, and a birefringent optical element provided in the optical heterodyne interference optical system is provided. Optical heterodyne detection is performed in the crystal, and the optical beat moving image signal having the phase shift and the beat frequency having a two-dimensional distribution characteristic in the beam cross section of the probe light is generated by optical mixing detection to display the image. The non-destructive inspection apparatus according to any one of claims 4 to 11, wherein the apparatus is configured to be applied to a system. 13. A light receiving means for converging laser light reflected from an observation area on the object to be measured by a lens, collimating the condensed laser light by a collimator, and providing the collimated laser light to a subsequent wavelength selecting means, Wavelength selecting means for selecting at least the probe light beam modulated according to the photoacoustic signal included in the laser light received from the light receiving means and providing the probe light beam to the subsequent optical heterodyne interference optical system; and Optical heterodyne detection by causing the probe light beam modulated according to the photoacoustic signal received from the means and the probe light beam as the reference light to interfere in birefringent optical means having a predetermined Bragg diffraction angle. Before having the phase shift and the beat frequency having a two-dimensional distribution characteristic in the beam cross section of the probe light. 13. The nondestructive inspection apparatus according to claim 12, further comprising: the optical heterodyne interference optical system which generates an optical beat moving image signal by optical heterodyne detection (optical mixed detection and optical beat detection) and provides the optical display to an image display system. . 14. The optical heterodyne interference optical system constitutes a Michelson interference optical system together with an interference mirror, and receives a probe light beam modulated according to the photoacoustic signal from the wavelength selection means, and The probe light beam as the reference light is received from the light splitting means, and the probe light beam modulated according to the photoacoustic signal and the probe light beam as the reference light are orthogonally and interfered in the birefringent optical means. 14. The non-destructive inspection apparatus according to claim 13, wherein the optical mixing detection is executed to output the optical beat moving image signal. 15. The nondestructive inspection apparatus according to claim 14, wherein the birefringent optical means includes a birefringent optical crystal. 16. The non-destructive inspection apparatus according to claim 14, wherein the birefringent optical crystal includes a bismuth silicon oxide optical crystal. 17. The nondestructive inspection device according to claim 14, wherein the birefringent optical crystal includes a calcite optical crystal. 18. The analysis / diagnosis processing system, wherein the static / dynamic holographic image received from the image forming means is sampled in synchronization with a fourth synchronization signal, and the static / elasticity characteristic and / or the static / dynamic holographic image are sampled. 18. The apparatus according to claim 2, further comprising a data collection unit configured to generate and output data on the static / dynamic holographic image used for analysis and diagnosis of a dynamic elastic characteristic. Non-destructive inspection equipment.