JPH1048039A - Method and device for ultrasonic detection, and ultrasonic image pick-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of signal wires regardless of the number of channels of a detecting array, by making the light of wide band pass through a wave-guiding channel formed by connecting plural optical ring resonators, and detecting the ultrasonic wave pressure as the variation of the resonance frequency of each resonator. SOLUTION: An ultrasonic wave receiver 10 forms plural sensor arrays 3i , and a wave- guiding channel 40 obtained by connecting the sensors 31 -3n , is connected with a light source part 50 and a spectral/demodulating part 60 from both edges through the photoconductive wires 51, 61. When the sensors 3i receive the ultrasonic wave, the variation of the refractive index is generated on the wave-guiding channel 40, and an optical signal in which the resonance frequency of each ring resonator is varied corresponding to the pressure of the ultrasonic wave, is generated. Each sensor 3i absorbs an optical component agreed with each resonance frequency, from the optical signal of wide band from the light source part 50, and the demodulating part 60 inputs an ultrasonic wave detecting signal. The resonance frequency components are separated from each other by the spectral dispersion, and the detecting signal of the separated sensor 3i , is respectively demodulated to generate an electric signal corresponding to the ultrasonic wave. Thereby the ultrasonic wave receiving signal of multichannel can be collected by two photoconductive wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic detection method and apparatus and an ultrasonic imaging apparatus, and more particularly to an ultrasonic detection method and apparatus using an array of optical ring resonators and an ultrasonic imaging apparatus.

[0002]

2. Description of the Related Art Detection of ultrasonic waves coming from a sound field to be detected
This is performed by an ultrasonic probe. The ultrasonic probe has an ultrasonic detector (detector) made of a piezoelectric material,
Thereby, the ultrasonic wave is detected as an electric signal.

[0003] When imaging the state of a sound field to be detected based on an ultrasonic wave reception signal, that is, when performing ultrasonic imaging, a plurality of detectors are arranged in an array as an ultrasonic probe. A multi-channel type is used.
Then, an image of the sound field to be detected is generated by subjecting the multi-channel echo reception signals to image reconstruction processing.

[0004]

SUMMARY OF THE INVENTION In order to transmit a received signal of each channel to an electric circuit on the imaging device main body side,
Individual signal lines are used. That is, the same number of signal wires as the number of channels are used. Therefore, for example, when an ultrasonic probe in a medical ultrasonic imaging apparatus is configured by an array of 128 channels, 128 signal line wirings are required.

[0005] These signal lines transmit the echo reception signal to the RF.
(radio frequency) Since the signal must be transmitted as it is, a coaxial cable is generally used. For this reason,
It is inevitable that the bundle of cables connecting the ultrasonic probe to the imaging device main body becomes thick.

From the viewpoint of improving the performance or the degree of freedom of the ultrasonic imaging, it is desirable that the array has as many channels as possible, but the number of channels is naturally limited because the thickness of the easy-to-handle cable is limited. Is done.
Such a limitation is particularly acute when constructing a two-dimensional array of ultrasound probes, which requires an extremely large number of detectors.

In order to reduce the number of connecting cables between the ultrasonic probe and the imaging apparatus main body, it is conceivable to arrange an electric circuit for processing the echo reception signal in the ultrasonic probe. New problems arise, such as the necessity of supplying power to the circuit and taking measures to generate heat in the electric circuit in the ultrasonic probe. Another problem is that the size of the ultrasonic probe increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an ultrasonic detection method and apparatus and an ultrasonic imaging apparatus which require a small number of signal lines regardless of the number of channels of a detection array. It is to realize.

The present invention has been made by applying an optical integrated circuit micro pressure sensor using a ring resonator. Such a pressure sensor is disclosed in, for example, IEICE Transactions, Vol. J79-C-
I No. 1 pp. 1-9 January 1996.

FIG. 15 shows a schematic configuration of this pressure sensor. 15A is a perspective view, and FIG. 15B is a cross-sectional view.
As shown in the figure, a ring resonator RLS which is a multiple interference optical circuit and a diaphragm DPM which is a pressure sensitive part are formed on a glass substrate GBS.

The ring resonator RLS includes a ring-shaped waveguide RNG and a directional coupler CPL for inputting and outputting light to and from the waveguide RNG.
It is composed of The directional coupler CPL is formed by the proximity between the waveguide WG and the waveguide portion on one side of the ring-shaped waveguide RNG. The optical input signal IN is input to one end of the waveguide WG, and the optical output signal OUT is output from the other end. The waveguide portion on the other side of the ring-shaped waveguide RNG passes over the diaphragm DPM.

The ring-shaped waveguide RNG and the waveguide WG are
It is formed on a glass substrate GBS by an optical integrated circuit technology. That is, it is formed by diffusing a substance (for example, aluminum (Al) or the like) that slightly increases the refractive index into the glass substrate GBS. Diaphragm DPM is
It is formed by etching the glass substrate GBS from the side opposite to the surface on which the ring resonator RLS is formed.

FIG. 16 shows a frequency characteristic of the optical output signal OUT of the ring resonator RLS, which shows a sharp resonance characteristic due to multiple interference of light. The graph of FIG. 16 shows that a frequency component corresponding to the resonance frequency is absorbed by the ring-shaped waveguide RNG through the directional coupler CPL. The light absorbed by the ring-shaped waveguide RNG circulates therein.

[0014] When pressure is applied to the diaphragm DPM, the diaphragm DPM bends, causing distortion inside. This distortion causes a change in the relative dielectric constant, that is, a change in the refractive index due to the photoelastic effect in the waveguide passing over the diaphragm DPM, and a phase change occurs in the guided light propagating therethrough.
Due to this phase change, the resonance frequency of the ring resonator RLS changes as shown by a broken line, for example. This frequency change Δ
Since f corresponds to the magnitude of the applied pressure, the pressure can be measured by measuring it.

[0015]

[Means for Solving the Problems]

[1] A first invention for solving the problem is that a plurality of optical ring resonators each having a different resonance frequency are connected by a common waveguide, and a wide band of light is passed through the waveguide. The ultrasonic pressure applied to the ring resonator is detected as a change in the resonance frequency of each optical ring resonator.

According to the first aspect of the present invention for solving the problems, a plurality of optical ring resonators are connected by a common waveguide, and a wide band of light is passed through the waveguide to be added to the plurality of optical ring resonators. Since the ultrasonic pressure is detected as a change in the resonance frequency of each optical ring resonator, a plurality of ultrasonic detection signals can be extracted through a common waveguide, thereby reducing the number of channels of the detection array. Regardless, it is possible to realize an ultrasonic detection method that requires only a small number of signal lines.

[2] According to a second aspect of the present invention, a plurality of optical ring resonators having different resonance frequencies from each other, a common waveguide connecting the plurality of optical ring resonators, and the waveguide are provided. Detecting means for detecting ultrasonic pressure applied to the plurality of optical ring resonators by transmitting light of a wide band to the optical ring resonators as changes in resonance frequencies of the individual optical ring resonators.

According to the second aspect of the present invention, a plurality of optical ring resonators are connected by a common waveguide, and a wide band of light is passed through the waveguide to be added to the plurality of optical ring resonators. Since the ultrasonic pressure is detected as a change in the resonance frequency of each optical ring resonator, a plurality of ultrasonic detection signals can be extracted through a common waveguide, thereby reducing the number of channels of the detection array. Regardless, it is possible to realize an ultrasonic detection device that requires only a small number of signal lines.

[3] A third invention for solving the problem is an ultrasonic imaging apparatus which receives an ultrasonic wave arriving from a test sound field and generates an image based on the ultrasonic reception signal, The ultrasonic waves are received by a plurality of optical ring resonators having different resonance frequencies, a common waveguide linking the plurality of optical ring resonators, and the plurality of light beams are transmitted by passing broadband light through the waveguide. It is characterized in that the ultrasonic pressure applied to the ring resonator is detected as a change in the resonance frequency of each optical ring resonator by a receiving means provided with a detecting means.

According to the third aspect of the present invention, a plurality of optical ring resonators are connected by a common waveguide, and a wide band of light is passed through the waveguide to be added to the plurality of optical ring resonators. Since the ultrasonic pressure is detected as a change in the resonance frequency of each optical ring resonator, a plurality of ultrasonic detection signals can be extracted through a common waveguide, thereby reducing the number of channels of the detection array. Regardless, it is possible to realize an ultrasonic imaging apparatus that requires a small number of signal lines.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiment.

FIG. 1 shows a block of the ultrasonic detecting apparatus.
The figure is shown. This device is an example of an embodiment of the present invention.
Note that an example of an embodiment relating to the device of the present invention is shown by the configuration of the present device. Further, an example of an embodiment relating to the method of the present invention is shown by the operation of the present apparatus. The same applies to other examples of the embodiment of the present invention.

As shown in FIG. 1, the ultrasonic wave receiver 10 comprises:
A plurality of sensors 3i on a substrate 20
The (i: 1 to n) array is formed, for example, in a circular shape. The value of n is, for example, 128. As the substrate 20, for example, a glass substrate is preferable in that a sensor array is formed by optical integrated circuit technology.

The shape of the array is not limited to a circle, but may be any desired shape such as an ellipse or a rectangle. Alternatively, a linear array may be used. Furthermore, a two-dimensional array may be used.

The plurality of sensors 31 to 3n are connected by a waveguide 40 in a single stroke. The waveguide 40 is an example of an embodiment of the waveguide according to the present invention. Waveguide 40
The light source unit 50 has an optical conductor 51 and an optical connector at one end.
The optical signal is supplied to the waveguide 40 through a (connector) 52.

The light conducting wire 51 is, for example, an optical fiber.
Etc. The light source unit 50 supplies a multicolor or wideband optical signal. The light source unit 50 is configured using, for example, a laser light source or the like. The generation of polychromatic light may be performed by spectrum sweeping.

At the other end of the waveguide 40, a spectroscopy / demodulation unit 60
Are connected through an optical conductor 61 and an optical connector 62. The spectroscopy / demodulation unit 60 performs spectroscopy and demodulation of the optical output signal of the waveguide 40. The light source unit 50 and the spectroscopy / demodulation unit 60 are an example of the embodiment of the detection unit in the present invention.

The sensor 3i has the same basic configuration as the pressure detector described in the above-mentioned document. That is, as shown in the plan view of FIG. 2 and the cross-sectional view taken along the line AA of FIG. The ring resonator 3i1 is an example of an embodiment of the optical ring resonator according to the present invention.

The ring resonator 3i1 includes a ring-shaped waveguide RNG and a directional coupler CPL for inputting and outputting light to and from the waveguide RNG.
It is composed of The directional coupler CPL is formed by a proximity between the waveguide 40 and a waveguide portion on one side of the ring-shaped waveguide RNG. The optical input signal IN is input to one end of the waveguide 40, and the optical output signal OUT is output from the other end. The waveguide portion on the other side of the ring-shaped waveguide RNG passes over the diaphragm 3i2.

The ring-shaped waveguide RNG and the waveguide 40 are
It is formed on the substrate 20 by, for example, an optical integrated circuit technique. That is, a substance (for example, aluminum (Al)) that slightly increases the refractive index of the substrate 20 is used.
Etc.). The diaphragm 3i2 is formed by, for example, etching the substrate 20 from the side opposite to the surface on which the ring resonator 3i1 is formed.

The diaphragm 3i2 receives an ultrasonic wave coming from the sound field to be detected as indicated by an arrow ARW. An acoustic matching layer M may be provided on the ultrasonic wave receiving surface of the diaphragm 3i2 if necessary.
CH is provided. The sound transmission medium MDI is filled in the etching hole.

FIG. 4 shows an optical output signal O of the ring resonator 3i1.
It shows sharp resonance characteristics due to multiple interference of light in the frequency characteristics of the UT. The graph of FIG. 4 shows that the frequency component corresponding to the resonance frequency passes through the directional coupler CPL to form the ring-shaped waveguide R.
It means that it is absorbed by NG. The absorbed light circulates in the ring-shaped waveguide RNG.

When an ultrasonic wave is applied to the diaphragm DPM, the diaphragm DPM bends in accordance with the pressure, and distortion occurs inside the diaphragm DPM. This distortion causes a change in the relative dielectric constant, that is, a change in the refractive index due to the photoelastic effect in the waveguide passing over the diaphragm DPM, and a phase change occurs in the guided light propagating therethrough. Due to this phase change, the ring resonator 3
The resonance frequency of i1 changes, for example, as indicated by the broken line.
This frequency change Δf corresponds to the magnitude of the ultrasonic pressure. That is, the resonance frequency is FM (frequ
An optical signal subjected to ency modulation) is obtained.

The plurality of sensors 31 to 31 configured as described above
3n connects the waveguides 40 in series and
Arranged above. The plurality of sensors 31 to 3n are configured such that the resonance frequencies of the ring resonators 3i1 are individually different. The difference in the resonance frequency is realized by making the dimensions of the ring-shaped waveguide RNG different.

In this way, from the multicolor optical signal supplied from the light source unit 50, the light components whose frequencies match the respective resonance frequencies are absorbed by the sensors 3i. Then, the optical signal after each of the resonance frequency components is absorbed is transmitted through the optical conductor 61 into the spectral / demodulation unit 60.
Is input to

That is, an optical signal having a so-called dark line spectrum is input to the spectral / demodulation unit 60. Each dark line spectrum represents the resonance frequency of each sensor 3i, and the frequency change indicates the ultrasonic pressure. Since the resonance frequencies are different from each other, the ultrasonic detection signals of the plurality of sensors 31 to 3n can be transmitted by one light conducting wire 61. That is, the ultrasonic detection signal is transmitted by frequency multiplexing.

An optical amplifier (not shown) is provided in the optical conductor 61 as needed. Among the optical amplifiers, for example, an optical amplifier (amplifier) using an erbium (Er) -doped optical fiber or the like is preferable because of its simple configuration.

The spectroscopy / demodulation unit 60 separates individual resonance frequency components by spectroscopy. Thereby, the detection signals of the sensor 3i are separated individually. The spectroscopy / demodulation unit 60 also generates an electric signal corresponding to the ultrasonic wave by performing FM detection (demodulation) on each detection signal. Thereby, an ultrasonic reception signal for each channel of the sensor array of the ultrasonic wave receiver 10 is obtained as an electric signal.

As described above, according to the present apparatus, multi-channel ultrasonic reception signals are collected simply by connecting the ultrasonic wave receiver 10, the light source unit 50, and the spectral / demodulation unit 60 with two optical conductors. be able to. That is, when the light source unit 50 and the spectroscopy / demodulation unit 60 are installed on the apparatus main body side, only two signal lines are required to connect them to the ultrasonic wave receiver 10 regardless of the number of channels. In addition, by increasing the number of optical conductors and increasing the number of systems, it is possible to easily cope with an enormous number of channels such as a two-dimensional array.

FIG. 5 shows another example of the embodiment of the present invention. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description is omitted. In this embodiment, the waveguide is composed of two systems, an input waveguide 41 and an output waveguide 42.

The input light from the light source unit 50 is supplied to one end of the input waveguide 41. The other end of the input waveguide 41 is terminated by a non-reflection terminator (terminator) 43. Output waveguide 4
A spectroscopy / demodulation unit 60 is connected to one end of 2. The other end of the output waveguide 42 is terminated by a non-reflection terminator (terminator) 44. A plurality of sensors 3i '(i: 1 to n) are arranged between the input waveguide 41 and the output waveguide 42.

The sensor 3i 'is shown in the plan view of FIG.
As shown in the cross-sectional view taken along the line BB of FIG. 5, the ring resonator 3i1 'and the diaphragm 3i2 of the pressure sensing unit are provided. The ring resonator 3i1 'includes a ring-shaped waveguide RNG and directional couplers CPL1 and CPL2 for inputting and outputting light to and from the waveguide RNG.

The directional coupler CPL1 is formed between the input waveguide 41 adjacent to the waveguide portion on one side of the ring-shaped waveguide RNG. The directional coupler CPL2 is formed between the ring-shaped waveguide RNG and the output waveguide 42 adjacent to the waveguide portion on the other side. Waveguide portions on both sides or either side of the ring-shaped waveguide RNG pass over the diaphragm 3i2.

A plurality of sensors 31 'constructed as described above
-3n 'are input waveguides 41 and output waveguides 42
The PLs 2 are formed on the substrate 20 in series. The plurality of sensors 31 'to 3n' are configured such that the resonance frequencies of the ring resonators 3i1 'are individually different. Therefore, the input waveguide 41 from the light source unit 50
The optical component having a frequency corresponding to the respective resonance frequency of the optical signal supplied to is extracted by each sensor 3i '.

The extracted light circulates in the ring-shaped waveguide RNG in each sensor 3i ', and a part of the light is transmitted to the output waveguide 42 through the directional coupler CPL2. As a result, an optical signal having a spectrum as shown in FIG. 8 is obtained in the output waveguide 42, for example. Therefore,
In the output waveguide 42, a group of optical signals having a frequency matching the resonance frequency of each ring resonator 3i1 ', that is,
An optical signal having a so-called bright-line spectrum is obtained, which is transmitted to the spectroscopy / demodulator 60 through the optical conductor 61. That is, optical transmission is performed by frequency multiplexing on a common transmission path. It is desirable to provide an optical amplifier in the light conducting wire 61.

The spectroscopy / demodulation unit 60 separates individual resonance frequency components by spectroscopy. Thus, the detection signals of the individual sensors 3i are separated individually. Spectroscopy / demodulation unit 60
Generates an electrical signal corresponding to the ultrasonic wave by performing FM detection (demodulation) on each detection signal. Thereby, an ultrasonic reception signal for each channel of the sensor array of the ultrasonic wave receiver 10 is obtained as an electric signal.

As described above, according to the present apparatus, multi-channel ultrasonic reception signals are collected simply by connecting the ultrasonic wave receiver 10, the light source unit 50, and the spectral / demodulation unit 60 with two optical conductors. be able to. That is, when the light source unit 50 and the spectroscopy / demodulation unit 60 are installed on the apparatus main body side, only two signal lines are required to connect them to the ultrasonic wave receiver 10 regardless of the number of channels. In addition, by increasing the number of optical conductors and increasing the number of systems, it is possible to easily cope with an enormous number of channels such as a two-dimensional array.

In this embodiment, the spectroscopy / demodulator 60 is used.
This is preferable in that the optical signal input to the device has a bright line spectrum. On the other hand, in the example of the embodiment shown in FIG. 1, although the optical signal input to the spectroscopy / demodulator 60 has a dark line spectrum, the input waveguide and the output waveguide of the optical signal in the ultrasonic wave receiver 10 are used. It is preferable in that the waveguide can be shared by one waveguide, and the configuration is simplified.

FIG. 9 shows a conceptual configuration of an example of the embodiment of the spectral / demodulation unit 60. As shown in the figure, the spectroscopy / demodulation unit 60 has an array of a plurality of spectroscopy / demodulators 8i (i: 1 to n) formed on a substrate 70. n is, for example, 128. The number of spectroscopy / demodulators 8i is equal to the number of sensors 3i or 3i 'in the ultrasonic receiver 10. The spectroscopy / demodulator 8i is a sensor 3i or 3i '.
Is configured in pairs.

The plurality of spectroscopy / demodulators 81 to 8n are connected to the waveguide 9
Linked by 0. An ultrasonic wave receiver 10 is connected to one end of the waveguide 90 through an optical conductor 61 and an optical connector 63.
An optical output signal is input from the device. The other end of the waveguide 90 is terminated by a non-reflection terminator (terminator) 100.

The spectroscopy / demodulator 8i is also configured using a ring resonator. That is, the plan view of FIG.
As shown in the CC sectional view of FIG.
It is composed of a ring-shaped waveguide RNG and a directional coupler CPL for inputting and outputting light to and from the ring-shaped waveguide RNG. Directional coupler CPL
Is formed by the proximity between the waveguide 90 and the waveguide portion on one side of the ring-shaped waveguide RNG.

Such a ring resonator 8i1 is connected to the sensor 3
It is configured by the optical integrated circuit technology similarly to the ring resonator 3i1 in i. A photodetector 8i2 is provided in a waveguide portion on the other side of the ring-shaped waveguide RNG. As the photodetector 8i2, for example, a photodiode (p
An appropriate light / electric conversion means such as a hotodiode is used.

The plurality of spectral / demodulators 81 to 8n thus configured are arranged on the substrate 70 by connecting the waveguides 90 in series. The ring resonator 8i1 of the spectroscopy / demodulator 8i is connected to the paired sensor 3i or 3i.
It is configured to have resonance characteristics tuned to the resonance characteristics of the ring resonator 3i1 or 3i1 'of i'. Specifically, a ring resonator 3i1 'as shown in FIG.
With respect to the resonance characteristics of (1) and (2), the configuration is such that the center frequency is shifted to have a slightly broad tuning characteristic. Thereby, the ring resonator 3i
The resonance frequency of 1 'comes to the slope of the tuning curve of the ring resonator 8i1.

By such tuning, the resonance frequency component of the ring resonator 3i1 'is separated from the optical signal passing through the waveguide 90. The split light circulates through the ring-shaped waveguide RNG, and this light is detected by the photodetector 8i2.

When the resonance frequency of the ring resonator 3i1 'changes in response to the ultrasound, it will move on the slope of the tuning curve of the ring resonator 8i1. For this reason, the level of the optical signal circulating through the ring-shaped waveguide RNG
Changes according to the frequency change, similarly to the case where slope detection is performed on the FM signal. Therefore, an analog electric signal whose amplitude changes according to the amplitude of the ultrasonic wave is obtained as the output signal of the photodetector 8i2.

Such an operation is performed by a plurality of spectral / demodulators 81.
To 8n, the sensor 3
The ultrasonic waves received by 1 ′ to 3n ′ are converted into electric signals. That is, the ultrasonic waves received by each channel of the sensor array of the ultrasonic receiver 10 are obtained as electric signals. However, since a DC component is superimposed on each electric signal, it is necessary to remove the DC component when using the signal.

With respect to the sensor 3i that generates an optical output signal having a dark line spectrum, the resonance characteristic of the ring resonator 3i1 as shown in FIG. It is configured to have a steeper tuning characteristic with a shifted frequency. Thereby, the ring resonator 8i1
At the slope of the absorption spectrum curve (tuning curve) of the ring resonator 3i1.

By such tuning, the resonance frequency component of the ring resonator 8i1 is separated from the optical signal passing through the waveguide 90. The split light circulates through the ring-shaped waveguide RNG, and this light is detected by the photodetector 8i2.

When the resonance frequency of the ring resonator 3i1 changes in response to the ultrasonic wave, the frequency components of different portions on the slope of the tuning curve of the ring resonator 3i1 are changed to the ring resonator 8i.
It will be synchronized with i1. For this reason, the level of the optical signal circulating in the ring-shaped waveguide RNG changes according to the frequency change, similarly to the case where the FM signal is slope-detected. Therefore, an analog electric signal that changes according to the amplitude of the ultrasonic wave is obtained as the output signal of the photodetector 8i2.

Such an operation is performed by a plurality of spectral / demodulators 81.
To 8n, the sensor 3
The ultrasonic waves received by 1 to 3n are respectively converted into electric signals. That is, the ultrasonic waves received by each channel of the sensor array of the ultrasonic receiver 10 are obtained as electric signals. However, since a DC component is superimposed on each electric signal, it is necessary to remove the DC component when using the signal.

Such a spectroscopy / demodulation unit 60 is preferable in that it can be manufactured in pairs using the same equipment as that for manufacturing the ultrasonic wave receiver 10. Note that the spectral / demodulation unit 60 is not limited to the above embodiment.

An ultrasonic imaging apparatus can be constructed by using the above ultrasonic detecting apparatus. FIG. 14 shows an example of an embodiment of an ultrasonic imaging apparatus. In FIG.
The same reference numerals are given to the same parts as those described above, and the description is omitted.
The ultrasonic wave receiver 10 has a through-hole at the center, and the ultrasonic wave transmitter 110 is arranged therein. The ultrasonic transmitter 110 is configured using, for example, an ultrasonic vibrator made of a piezoelectric material. The ultrasonic transmitter 110 is a transmitting unit 12
0 to transmit ultrasonic waves to the sound field to be measured.

The echo corresponding to the transmitted wave is the ultrasonic wave receiver 1
0 are detected by the sensors 31 to 3n of the light source unit 50, and the spectral /
The signal is input to the demodulation unit 60.

Each change in the optical spectrum is demodulated into an analog electric signal in the spectroscopy / demodulation unit 60, and an echo reception signal for each channel of the array of the sensors 31 to 3n is obtained. That is, echo reception signals of a plurality of channels similar to those received by the conventional ultrasonic transducer array are obtained. Here, the ultrasonic wave receiver 10 and the light source unit 5
0 and the spectroscopy / demodulation unit 60 are an example of an embodiment of a receiving unit in the present invention.

The image generator 130 generates an image based on the echo reception signal for each channel. As the image generating unit 130, the same unit as the image generating unit in the ultrasonic imaging apparatus using the conventional ultrasonic transducer array can be used. The generated image is displayed on the display unit 140 as a visible image.

In such an ultrasonic imaging apparatus, the signal line connecting the ultrasonic wave receiver 10 and the main body of the imaging apparatus can be composed of only two optical conductors irrespective of the number of channels for the detection signal. . In addition, by increasing the number of optical conductors and increasing the number of systems, it is possible to easily cope with an enormous number of channels such as a two-dimensional array.

[0067]

As described in detail above, according to the first aspect of the present invention for solving the problems, a plurality of optical ring resonators are connected by a common waveguide, and a broadband light is transmitted through this waveguide. As a result, the ultrasonic pressure applied to a plurality of optical ring resonators is detected as a change in the resonance frequency of each optical ring resonator, so that a plurality of ultrasonic detection signal groups can be extracted through a common waveguide. Thereby, it is possible to realize an ultrasonic detection method that requires a small number of signal lines regardless of the number of channels of the detection array.

According to the second aspect of the present invention for solving the problems, a plurality of optical ring resonators are connected by a common waveguide,
By transmitting the broadband light through this waveguide, the ultrasonic pressure applied to the plurality of optical ring resonators is detected as a change in the resonance frequency of each optical ring resonator. The ultrasonic wave can be extracted through a common waveguide, thereby realizing an ultrasonic detection device that requires a small number of signal lines regardless of the number of channels of the detection array.

According to the third aspect of the present invention, a plurality of optical ring resonators are connected by a common waveguide.
By transmitting the broadband light through this waveguide, the ultrasonic pressure applied to the plurality of optical ring resonators is detected as a change in the resonance frequency of each optical ring resonator. It can be extracted through a common waveguide, thereby realizing an ultrasonic imaging apparatus that requires a small number of signal lines regardless of the number of channels of the detection array.

[Brief description of the drawings]

FIG. 1 is a block diagram of a device according to an example of an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a sensor in a device according to an example of an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a sensor in the device according to an example of the embodiment of the present invention.

FIG. 4 is an explanatory diagram of an operation of a sensor in the device according to the embodiment of the present invention;

FIG. 5 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a sensor in the device according to an example of the embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a sensor in the device according to an example of the embodiment of the present invention.

FIG. 8 is an explanatory diagram of an operation of a sensor in the device according to an example of the embodiment of the present invention.

FIG. 9 is a schematic configuration diagram of a spectroscopy / demodulation unit in an apparatus according to an example of an embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of a spectrometer / demodulator in an apparatus according to an example of an embodiment of the present invention.

FIG. 11 is a schematic configuration diagram of a spectroscopy / demodulator in an apparatus according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram of an operation of the spectroscopy / demodulator in the apparatus according to the embodiment of the present invention;

FIG. 13 is an explanatory diagram of the operation of the spectroscopy / demodulator in the apparatus according to one embodiment of the present invention.

FIG. 14 is a block diagram of an apparatus according to an example of an embodiment of the present invention.

FIG. 15 is a schematic configuration diagram of a ring resonator.

FIG. 16 is an explanatory diagram of the operation of the ring resonator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ultrasonic wave receiver 20 Substrate 31-3n, 31'-3n 'Sensor 40 Waveguide 41 Input waveguide 42 Output waveguide 43,44 Terminator 50 Light source part 51 Optical line 52 Connector 60 Spectral / demodulation part 61 Light ray Path 62, 63 Connector 3i1, 3i1 'Ring resonator 3i2 Diaphragm CPL, CPL1, CPL2 Directional coupler RNG Ring-shaped waveguide MCH Acoustic matching layer MDI Sound transmission medium 70 Substrate 81-8n Spectral / demodulator 90 Waveguide REFERENCE SIGNS LIST 100 Terminator 8i1 Ring resonator 8i2 Photodetector 110 Ultrasonic wave transmitter 120 Transmitter 130 Image generator 140 Display

Claims (3)

[Claims] A plurality of optical ring resonators each having a different resonance frequency are connected by a common waveguide, and an ultrasonic pressure applied to the plurality of optical ring resonators is individually reduced by passing broadband light through the waveguide. And detecting the change as a change in the resonance frequency of the optical ring resonator. 2. A plurality of optical ring resonators each having a different resonance frequency, a common waveguide connecting the plurality of optical ring resonators, and a plurality of optical ring resonators formed by passing broadband light through the waveguide. Detecting means for detecting the ultrasonic pressure applied to the resonator as a change in the resonance frequency of each optical ring resonator. 3. An ultrasonic wave arriving from a test sound field is received,
An ultrasonic imaging apparatus that generates an image based on an ultrasonic reception signal, wherein reception of ultrasonic waves is performed by a plurality of optical ring resonators each having a different resonance frequency, and a common linking the plurality of optical ring resonators. Receiving means comprising: a waveguide; and detecting means for detecting ultrasonic pressure applied to the plurality of optical ring resonators by passing broadband light through the waveguide as a change in the resonance frequency of each optical ring resonator. An ultrasonic imaging apparatus characterized in that the ultrasonic imaging apparatus is configured to perform the above operation.