JP2020163107A - Photoacoustic wave measurement apparatus - Google Patents

Abstract

To provide a method for performing photoacoustic wave measurement by irradiating a measurement object with pulse light having a wavelength and, immediately after that, irradiating the measurement object with pulse light having a different wavelength.SOLUTION: A photoacoustic wave measurement apparatus 100 comprises: an ultrasound pulse output unit 2 for outputting ultrasound pulses PU; a laser light output device 1 for outputting laser light PL; and a measurement unit 4 for measuring a measurement object 200 on the basis of a reflection wave US of the ultrasound pulses reflected by the measurement object and a photoacoustic wave AW generated at the measurement object by the laser light. The laser light output device comprises: an excitation laser for outputting laser light having a predetermined wavelength as first pulses having a predetermined frequency; an acoustic optical modulator that receives the first pulses and, for each of the first pulses, determines any one of a plurality of optical paths before outputting the pulse; and a wavelength change unit that receives advancing light having advanced through the respective optical paths and changes the advancing light to light having wavelengths differing from each other before performing output.SELECTED DRAWING: Figure 14

Description

The present invention relates to measurement using a device that outputs laser light of a plurality of wavelengths as pulses.

Conventionally, it has been known that measurement (for example, measurement of oxygen saturation in blood) is performed by a response (for example, absorption coefficient) obtained by irradiating a test object (for example, a living body) with pulsed light. .. It is also known that the response obtained from the object to be measured differs depending on the wavelength of the pulsed light. Therefore, it is desired to irradiate the object to be measured with pulsed light having a plurality of wavelengths from the viewpoint of improving the measurement accuracy. At that time, if the time from irradiating a certain point P of the object to be measured with pulsed light of a certain wavelength to irradiating the pulsed light of another wavelength to the point P becomes longer, the object to be measured moves (for example, (Body movement) causes deterioration of measurement accuracy.

However, there is no known technique for irradiating pulsed light of a certain wavelength and then immediately irradiating pulsed light of another wavelength. For example, in Patent Document 1, Patent Document 2, and Patent Document 3, although there is a description that laser light having different wavelengths is combined, a pulse light having a certain wavelength is irradiated and then a pulse having another wavelength is immediately generated. It is not about irradiating light.

Japanese Unexamined Patent Publication No. 2011-107894 International Publication No. 2017/138619 Japanese Unexamined Patent Publication No. 2016-101393

Therefore, an object of the present invention is to perform photoacoustic wave measurement by irradiating a measurement target with pulsed light of a certain wavelength and then immediately irradiating pulsed light of another wavelength.

The photoacoustic wave measuring device according to the present invention includes a laser light output device that outputs laser light and a measuring unit that measures the measurement target based on the photoacoustic wave generated in the measurement target by the laser light. The laser light output device receives a pulse laser output unit that outputs laser light of a predetermined wavelength as a first pulse, and receives the first pulse, and each of the first pulses is divided into one of a plurality of optical paths. The output of the optical path determination unit that determines and outputs the optical path, the wavelength change unit that receives the traveling light traveling through each of the plurality of optical paths and changes the wavelength to a different wavelength, and the output of the wavelength change unit are combined. It is configured to have a combiner.

According to the photoacoustic wave measuring device configured as described above, the laser light output device outputs the laser light. The measuring unit measures the measurement target based on the photoacoustic wave generated in the measurement target by the laser light. According to the laser light output device, the pulse laser output unit outputs a laser light having a predetermined wavelength as a first pulse. The optical path determination unit receives the first pulse, determines an optical path in any one of a plurality of optical paths for each of the first pulses, and outputs the optical path. The wavelength changing unit receives the traveling light traveling through each of the plurality of optical paths, changes the wavelengths to different wavelengths, and outputs the light. The combiner combines the output of the wavelength change section.

The photoacoustic wave measuring device according to the present invention includes an ultrasonic pulse output unit that outputs an ultrasonic pulse, so that the measuring unit further measures the reflected wave reflected by the ultrasonic pulse in the measurement target. It may be.

In the photoacoustic wave measuring device according to the present invention, the first pulse has a predetermined frequency, and the optical path determining unit sets the predetermined frequency from each of the plurality of optical paths of the plurality of optical paths. A second pulse having a frequency divided by the number and having different phases may be output.

In the photoacoustic wave measuring device according to the present invention, the combiner may output a third pulse having the predetermined frequency.

In the photoacoustic wave measuring device according to the present invention, the pulse laser output unit may be an excitation laser.

In the photoacoustic wave measuring device according to the present invention, the optical path determining unit may be an acousto-optic modulator or an acoustic-optical deflector.

In the photoacoustic wave measuring apparatus according to the present invention, the wavelength changing portion has a polarization inversion portion in which the traveling light propagates and is arranged at a predetermined interval, and the predetermined interval is the traveling. It may be different for each light.

In the photoacoustic wave measuring apparatus according to the present invention, the wavelength changing portion has a nonlinear optical crystal substrate on which the polarization inversion portion is formed, and the centroid of the polarization inversion portion is the nonlinear optical crystal substrate. It may be arranged on a straight line parallel to the x-axis.

In the photoacoustic wave measuring device according to the present invention, the centroid of the polarization reversal portion may be arranged on a straight line parallel to the traveling direction of the traveling light.

In the photoacoustic wave measuring device according to the present invention, the wavelength changing portion may have one nonlinear optical crystal substrate in which all of the polarization inversion portions are formed.

In the photoacoustic wave measuring device according to the present invention, the wavelength changing portion has a nonlinear optical crystal substrate on which the polarization inversion portion is formed, and the nonlinear optical crystal substrate is provided for each propagating traveling light. It may be done.

In the photoacoustic wave measuring device according to the present invention, the wavelength changing portion may have a nonlinear optical crystal through which the traveling light propagates.

The photoacoustic wave measuring device according to the present invention may include an optical fiber that receives the output of the combiner at one end and outputs the output from the other end.

The photoacoustic wave measuring device according to the present invention may include a timing control unit that matches the output of the optical path determination unit with the timing of the output of the first pulse.

In the photoacousto-optic wave measuring device according to the present invention, the optical path determination unit receives the first pulse, determines the optical path to any one of a plurality of optical paths for each of the first pulses, and outputs the optical path. The optical path is determined to be one of one or more optical paths for each pulse of the output of the first acousto-optic modulator and the output of the first acousto-optic modulator. It may have a second acousto-optic modulator to output.

In the photoacousto-wave measuring apparatus according to the present invention, the first acousto-optic modulator diffracts or advances each of the first pulses and outputs the device, and the second acousto-optic modulator outputs the first pulse. The first pulse may be diffracted and output in a straight line, and the first pulse may be diffracted and output in a straight line.

In the photoacousto-wave measuring apparatus according to the present invention, the first acousto-optic modulator diffracts or advances each of the first pulses and outputs the device, and the second acousto-optic modulator outputs the first pulse. The first pulse may be diffracted and diffracted or straightened to be output, and the first pulse may be received and straightened to be output.

In the photoacousto-wave measuring apparatus according to the present invention, the first acousto-optic modulator diffracts or advances each of the first pulses and outputs the device, and the second acousto-optic modulator outputs the first pulse. Each pulse of the output of the first acousto-optic modulator may be diffracted or linearly output.

It is a figure which shows the structure of the laser light output device 1 which concerns on 1st Embodiment. It is a top view of the wavelength change part 14 which concerns on 1st Embodiment. It is a timing chart of the first pulse P1, the second pulse (before wavelength conversion) P2a, the second pulse (after wavelength conversion) P2b, and the third pulse (after filtering) P3b according to the first embodiment. It is a top view of the wavelength change part 14 which concerns on the modification of 1st Embodiment. It is a figure which shows the structure of the laser light output device 1 which concerns on the 2nd Embodiment. It is a figure which shows the structure of the laser light output device 1 which concerns on 3rd Embodiment. 3 is a timing chart of the first pulse P1, the second pulse (before wavelength conversion) P2a, the second pulse (after wavelength conversion) P2b, and the third pulse (after filtering) P3b according to the third embodiment. It is a figure which shows the structure of the laser light output device 1 which concerns on 4th Embodiment. It is an enlarged view of the vicinity of the optical path determination part (the first acousto-optic modulator (AOM) 12a and the second acousto-optic modulator (AOM) 12b) in the laser light output device 1 according to the fourth embodiment. It is a figure which shows the structure of the laser light output device 1 which concerns on 5th Embodiment. It is an enlarged view of the vicinity of the optical path determination part (the first acousto-optic modulator (AOM) 12a and the second acousto-optic modulator (AOM) 12b) in the laser light output device 1 according to the fifth embodiment. It is an enlarged view of the vicinity of the optical path determination part (the first acousto-optic modulator (AOM) 12a and the second acousto-optic modulator (AOM) 12b) in the laser light output device 1 according to the modified example of the fourth embodiment. It is a functional block diagram which shows the structure of the photoacoustic wave measuring apparatus 100 which concerns on the 6th Embodiment of this invention. It is a functional block diagram which shows the structure of the photoacoustic wave measuring apparatus 100 which concerns on 7th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 is a diagram showing a configuration of a laser light output device 1 according to the first embodiment. FIG. 2 is a plan view of the wavelength changing unit 14 according to the first embodiment. FIG. 3 is a timing chart of the first pulse P1, the second pulse (before wavelength conversion) P2a, the second pulse (after wavelength conversion) P2b, and the third pulse (after filtering) P3b according to the first embodiment. In FIG. 3, the thickness of the line indicating the pulse and the type of the line (solid line or broken line) are changed according to the wavelength.

The laser light output device 1 according to the first embodiment includes an excitation laser (pulse laser output unit) 10, an optical attenuator (ATT) 11, an acousto-optic modulator (optical path determination unit) (AOM) 12, and a wavelength change unit (AOM). It includes a PPLN) 14, a mirror 15, a dichroic mirror (combiner) (DCM) 16, a filter (F) 17, an optical fiber (MMF) 18, and a timing control circuit (timing control unit) 19.

The excitation laser (pulse laser output unit) 10 outputs a laser beam having a predetermined wavelength W1 [nm] as a first pulse P1 (see FIG. 3) having a predetermined frequency (for example, 2 kHz). The excitation laser 10 is, for example, a Yb: YAG laser.

The optical attenuator (ATT) 11 attenuates the first pulse P1 and supplies it to the acousto-optic modulator 12.

The acousto-optic modulator (optical path determination unit) (AOM) 12 receives the first pulse P1 and determines and outputs an optical path to one of a plurality of optical paths OP1 and OP2 for each of the first pulses P1. ..

For example, referring to FIGS. 1 and 3, when the acousto-optic modulator 12 receives the odd-numbered (1, 3, 5, ...) Pulse of the first pulse P1, the acousto-optic modulator 12 acoustically Don't give waves. Then, the odd-numbered pulse of the first pulse P1 passes straight through the acousto-optic modulator 12 as it is (optical path OP1).

Further, when the acousto-optic modulator 12 receives the even-numbered (2nd, 4th, 6th, ...) pulses of the first pulse P1, an acoustic wave (angular frequency ω2) is applied to the acousto-optic modulator 12. Then, the even-numbered pulse of the first pulse P1 passes through the acousto-optic modulator 12 while diffracting to some extent (optical path OP2).

However, when the acousto-optic modulator 12 receives the odd-th pulse of the first pulse P1, the acousto-optic modulator 12 may be given an acoustic wave (angular frequency ω1) (however, ω1 is different from ω2). ..

As a result, the acousto-optic modulator 12 has a frequency (1 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (2) from each of the plurality of optical paths OP1 and OP2. And, the second pulse (before wavelength conversion) P2a, which is a pulse whose phase is 180 degrees different from each other, is output.

The timing control circuit (timing control unit) 19 matches the output of the acousto-optic modulator (optical path determination unit) 12 with the output timing of the first pulse P1. The result of adjusting the timing is as described above with reference to FIG. The timing control circuit 19 receives a signal from the excitation laser (pulse laser output unit) 10 synchronized with the output timing of the first pulse P1, and controls the output timing of the acousto-optic modulator 12 based on this signal. ..

The wavelength change unit (PPLN) 14 receives the traveling light (the second pulse P2a) that has traveled through each of the plurality of optical paths OP1 and OP2, changes the wavelengths to different wavelengths, and outputs the light. The output of the wavelength changing unit 14 is the second pulse (after wavelength conversion) P2b.

With reference to FIG. 3, the wavelength changing unit 14 receives the second pulse P2a that has advanced the optical path OP1 (wavelength W1 [nm]) and converts it into the second pulse P2b (wavelength W2 [nm]). .. Further, the wavelength changing unit 14 receives the second pulse P2a that has advanced the optical path OP2 (wavelength W1 [nm]) and converts it into the second pulse P2b (wavelength W3 [nm]).

With reference to FIG. 2, the wavelength changing unit 14 has an LN crystal substrate 142 and a polarization inversion unit 144. Note that, in FIG. 2, unlike FIG. 1, the x-axis direction of the LN crystal substrate 142 is shown parallel to the lateral direction of the paper surface for convenience of illustration.

The polarization inversion portion 144 propagates the traveling light (the second pulse P2a). The polarization inversion portion 144 includes one in which the second pulse P2a traveling in the optical path OP1 propagates and one in which the second pulse P2a traveling in the optical path OP2 propagates. The polarization inversion portion 144 is PPLN (periodic polarization inversion lithium niobate) in FIG. 2, but is not limited to this, and may be, for example, PPLT (lithium tantalate) or PPKTP.

The polarization inversion portions 144 through which the second pulse P2a traveling in the optical path OP1 propagates are arranged at a predetermined interval D1. The polarization inversion portions 144 through which the second pulse P2a traveling in the optical path OP2 propagates are arranged at a predetermined interval D2. The predetermined interval is different for each traveling light. That is, the predetermined interval D1 and the predetermined interval D2 are different.

A polarization inversion portion 144 is formed on the LN crystal substrate 142. There is only one LN crystal substrate 142, and all of the polarization inversion portions 144 are formed. In the first embodiment, the LN crystal substrate 142 may be a nonlinear optical crystal substrate, not just an LN crystal substrate. Similarly, in other embodiments, a nonlinear optical crystal substrate can be used instead of the LN crystal substrate.

The center of gravity 144c of the polarization inversion portion 144 propagated by the second pulse P2a traveling in the optical path OP1 is arranged on a straight line parallel to the x-axis of the LN crystal substrate 142. The center of gravity 144c of the polarization inversion portion 144 in which the second pulse P2a traveling in the optical path OP2 propagates is also arranged on a straight line parallel to the x-axis of the LN crystal substrate 142. The center of gravity 144c of the polarization inversion portion 144 coincides with the center of gravity when gravity acts uniformly on the polarization inversion portion 144.

The mirror 15 receives the second pulse (after wavelength conversion) P2b that has traveled in the optical path OP2 and reflects it toward the dichroic mirror 16.

The dichroic mirror (combiner) (DCM) 16 receives from the wavelength change unit 14 the second pulse (after wavelength conversion) P2b output by the wavelength change unit 14 that has traveled through the optical path OP1. The dichroic mirror 16 further receives from the mirror 15 the second pulse (after wavelength conversion) P2b output by the wavelength changing unit 14 that has traveled through the optical path OP2. Further, the dichroic mirror 16 combines the second pulse (after wavelength conversion) P2b output by the wavelength changing unit 14 with the one traveling through the optical path OP1 and the traveling through the optical path OP2 to obtain a predetermined frequency (after wavelength conversion). The third pulse (before filtering) P3a having (2kHz) is output.

However, in addition to the third pulse (before filtering) P3a, the output of the dichroic mirror 16 includes laser light (pump light) of wavelength W1 [nm] output by the excitation laser 10 and red generated by the wavelength change unit 14. The idler light in the outer region is mixed. When laser light (pump light) is applied to the wavelength changing unit 14, signal light and the above-mentioned idler light are generated due to optical parametric generation. The signal light is the output of the wavelength changing unit 14 (second pulse (after wavelength conversion) P2b) (the same applies to the wavelength changing unit of other embodiments).

The filter (F) 17 removes the pump light and the idler light from the third pulse (before filtering) P3a, and outputs the third pulse (after filtering) P3b.

The optical fiber (MMF) 18 receives the third pulse P3a output from the dichroic mirror 16 at one end thereof via the filter 17 and outputs the third pulse P3a from the other end.

Next, the operation of the first embodiment will be described.

First, the excitation laser 10 outputs a laser beam having a predetermined wavelength W1 [nm] as a first pulse P1 (see FIG. 3) having a predetermined frequency (for example, 2 kHz). The first pulse P1 is attenuated by the optical attenuator 11 and then given to the acousto-optic modulator 12. The timing control circuit 19 controls the output timing (see FIG. 3) of the acousto-optic modulator 12.

When the acousto-optic modulator 12 receives the odd-numbered (1, 3, 5, ...) Pulse of the first pulse P1, no acoustic wave is applied to the acousto-optic modulator 12. As a result, the odd-numbered pulse of the first pulse P1 passes straight through the acousto-optic modulator 12 as it is (optical path OP1). Therefore, the traveling light traveling in the optical path OP1 is the second pulse (before wavelength conversion) P2a having a frequency (1 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (2). Become.

When the acousto-optic modulator 12 receives the even-numbered (2nd, 4th, 6th, ...) pulses of the first pulse P1, the acousto-optic modulator 12 is provided with an acoustic wave (angular frequency ω2). As a result, the even-numbered pulse of the second pulse P1 passes through the acousto-optic modulator 12 while diffracting to some extent (optical path OP2). Therefore, the traveling light traveling in the optical path OP2 is the second pulse (before wavelength conversion) P2a having a frequency (1 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (2). Become.

Moreover, the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP1 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP2 are 180 degrees different.

The traveling light traveling through the optical path OP1 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) propagates in the polarization inversion portion 144 arranged at a predetermined interval D1 in the wavelength change portion 14. The wavelength is converted to W2 [nm] to become the second pulse (after wavelength conversion) P2b, which is given to the dichroic mirror 16.

The traveling light traveling through the optical path OP2 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) propagates in the polarization inversion portion 144 arranged at a predetermined interval D2 in the wavelength change portion 14. The wavelength is converted to W3 [nm] to become the second pulse (after wavelength conversion) P2b, which is reflected by the mirror 15 and then given to the dichroic mirror 16.

Of the second pulse (after wavelength conversion) P2b output by the wavelength change unit 14, the wavelength W2 [nm] and the wavelength W3 [nm] are combined by the dichroic mirror 16 and have a predetermined frequency (2 kHz). ) Is the third pulse (before filtering) P3a.

The third pulse (before filtering) P3a becomes the third pulse (after filtering) P3b after the pump light and idler light are removed by the filter 17. The third pulse (after filtering) P3b is given to one end of the optical fiber 18 and output from the other end.

According to the first embodiment, the third pulse (after filtering) P3b can be output from the optical fiber 18. The third pulse (after filtering) P3b is irradiated with pulsed light having a wavelength W2 [nm] and immediately (for example, 500 microseconds) irradiated with pulsed light having another wavelength W3 [nm]. .. That is, according to the first embodiment, it is possible to irradiate a pulsed light having a certain wavelength and then immediately irradiate a pulsed light having another wavelength.

In the first embodiment, the center of gravity 144c of the polarization inversion portion 144 is arranged on a straight line parallel to the x-axis of the LN crystal substrate 142 (see FIG. 2), but the figure of the polarization inversion portion 144 is shown. Regarding the arrangement of the core 144c, the following modified examples can be considered.

FIG. 4 is a plan view of the wavelength changing unit 14 according to the modified example of the first embodiment. Note that, in FIG. 4, unlike FIG. 1, for convenience of illustration, the x-axis direction of the LN crystal substrate 142 is shown parallel to the lateral direction of the paper surface, as in FIG. 2.

With reference to FIG. 4, in the wavelength changing portion 14 according to the modified example of the first embodiment, the polarization inversion portion 144 through which the traveling light (second pulse P2a traveling in the optical path OP1) propagates has a predetermined interval D1. 144c is arranged on a straight line (for example, on the traveling direction) parallel to the traveling direction of the traveling light (second pulse P2a traveling in the optical path OP1). Further, the polarization inversion portions 144 through which the traveling light (second pulse P2a traveling in the optical path OP2) propagates are arranged at a predetermined interval D2, and the center 144c thereof is the traveling light (second traveling in the optical path OP2). The pulse P2a) is arranged on a straight line parallel to the traveling direction (for example, on the traveling direction).

According to the modification of the first embodiment as described above, the vertical length (length in the Y-axis direction) of the polarization inversion portion 144 can be shortened as compared with the case of the first embodiment. it can.

Further, in the first embodiment, the polarization inversion portion 144 is provided in the wavelength change portion 14 (see FIGS. 2 and 4), but the traveling light propagates without providing the polarization inversion portion 144. A modified example having a non-linear optical crystal is also conceivable. For example, the wavelength changing unit 14 can be OPO (optical parametric oscillation), SHG (second harmonic generation), THG (third harmonic generation), or the like by BPM (birefringence phase matching).

Second Embodiment In the laser light output device 1 according to the second embodiment, there is only one LN crystal substrate 142 in that the LN crystal substrate is provided for each propagating light. It is different from the laser light output device 1 according to the form.

FIG. 5 is a diagram showing the configuration of the laser light output device 1 according to the second embodiment. The laser light output device 1 according to the second embodiment includes an excitation laser (pulse laser output unit) 10, an optical attenuator (ATT) 11, an acousto-optic modulator (optical path determination unit) (AOM) 12, and a romvoid prism 13. , Wavelength change unit (PPLN) 14a, 14b, mirror 15, dichroic mirror (combiner) (DCM) 16, filter (F) 17, optical fiber (MMF) 18, timing control circuit (timing control unit) 19. .. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

Excitation laser (pulse laser output unit) 10, optical attenuator (ATT) 11, acousto-optic modulator (optical path determination unit) (AOM) 12, mirror 15, dichroic mirror (combiner) (DCM) 16, filter (F) ) 17, the optical fiber (MMF) 18, and the timing control circuit (timing control unit) 19 are the same as those in the first embodiment, and the description thereof will be omitted.

The romvoid prism 13 receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP2, and changes the optical path so as to be parallel to the optical path and away from the optical path OP1.

The wavelength change unit (PPLN) 14a receives the second pulse P2a that has advanced the optical path OP1 (wavelength W1 [nm]) from the acousto-optic modulator 12 and converts it into the second pulse P2b (wavelength W2 [nm]). Convert. The configuration of the wavelength changing portion 14a corresponds to the polarization inversion portion 144 arranged at a predetermined interval D1 in FIG. 2 or FIG. 4 and the LN crystal substrate 142 on which the polarization inversion portion 144 is formed.

The wavelength change unit (PPLN) 14b receives the second pulse P2a that has advanced the optical path OP2 (wavelength W1 [nm]) from the romvoid prism 13 and converts it into the second pulse P2b (wavelength W3 [nm]). To do. The configuration of the wavelength changing portion 14b corresponds to the polarization inversion portion 144 arranged at a predetermined interval D2 in FIG. 2 or FIG. 4 and the LN crystal substrate 142 on which the polarization inversion portion 144 is formed.

The LN crystal substrate included in the wavelength changing portion 14a and the LN crystal substrate included in the wavelength changing portion 14b are different from each other. That is, the LN crystal substrate possessed by the wavelength changing unit 14a and the LN crystal substrate possessed by the wavelength changing unit 14b are provided for each propagating traveling light (one in which the optical path OP1 is advanced and one in which the optical path OP2 is advanced). There is.

The operation of the second embodiment is the same as that of the first embodiment, and the description thereof will be omitted.

According to the second embodiment, since the LN crystal substrate is provided for each propagating traveling light (one traveling in the optical path OP1 and one traveling in the optical path OP2), the LN crystal substrate is provided according to predetermined intervals D1 and D2. The manufacturing conditions of the polarization reversing section 144 can be set, and the wavelength changing sections 14a and 14b can be easily manufactured.

Third Embodiment In the laser light output device 1 according to the third embodiment, the acousto-optic deflector (AOD) (optical path determination unit) 120 is replaced with the acousto-optic modulator (AOM) (optical path determination unit) 12. The point of use is different from the laser light output device 1 according to the first embodiment.

FIG. 6 is a diagram showing the configuration of the laser light output device 1 according to the third embodiment. FIG. 7 is a timing chart of the first pulse P1, the second pulse (before wavelength conversion) P2a, the second pulse (after wavelength conversion) P2b, and the third pulse (after filtering) P3b according to the third embodiment. In FIG. 7, the thickness of the line indicating the pulse and the type of line (solid line, broken line, or alternate long and short dash line) are changed according to the wavelength.

The laser light output device 1 according to the third embodiment includes an excitation laser (pulse laser output unit) 10, an optical attenuator (ATT) 11, an acoustic optical deflector (AOD) (optical path determination unit) 120, and a wavelength change unit (a wavelength change unit). It includes a PPLN) 14, a mirror 154, a dichroic mirror (attenuator) (DCM) 162, 164, a filter (F) 17, an optical fiber (MMF) 18, and a timing control circuit (timing control unit) 19. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The excitation laser (pulse laser output unit) 10, the optical attenuator (ATT) 11, the filter (F) 17, the optical fiber (MMF) 18, and the timing control circuit (timing control unit) 19 are the same as those in the first embodiment. Yes, the description is omitted. However, the timing control circuit 19 controls the output timing (see FIG. 7) of the acoustic-optical deflector 120.

The acoustic-optical deflector (AOD) (optical path determination unit) 120 receives the first pulse P1 and determines the optical path in any one of a plurality of optical paths OP1, OP2, and OP3 for each of the first pulse P1. Output.

For example, with reference to FIGS. 6 and 7, the acoustic-optical deflector 120 received the 1 + 3Nth (1, 4, 7, ...) (where N is an integer greater than or equal to 0) pulse of the first pulse P1. At this time, no acoustic wave is applied to the acoustic optical deflector 120. Then, the 1 + 3Nth pulse of the first pulse P1 passes straight through the acoustic-optical deflector 120 (optical path OP1).

Further, when the acoustic-optical deflector 120 receives the 2 + 3Nth (2nd, 5th, 8th, ...) Pulse of the first pulse P1, an acoustic wave (angular frequency ω2) is applied to the acoustic-optical deflector 120. Then, the 2 + 3Nth pulse of the first pulse P1 passes through the acoustic-optical deflector 120 while diffracting to some extent (optical path OP2).

Further, when the acoustic-optical deflector 120 receives the 3 + 3Nth (3, 6, 9, ...) Pulse of the first pulse P1, the acoustic optical deflector 120 receives an acoustic wave (angular frequency ω3) (however, ω3). Is different from ω2). Then, the 3 + 3Nth pulse of the first pulse P1 passes through the acoustic-optical deflector 120 while diffracting to some extent (optical path OP3). However, the angle formed by the optical path OP3 with the optical path OP1 (however, less than 90 degrees) is larger than the angle formed by the optical path OP2 with the optical path OP1 (however, less than 90 degrees).

When the acoustic optical deflector 120 receives the 1 + 3Nth pulse of the first pulse P1, the acoustic optical deflector 120 is given an acoustic wave (angular frequency ω1) (however, ω1 is different from ω2 and ω3). You may.

As a result, the acoustic-optical deflector 120 has a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3) from each of the plurality of optical paths OP1, OP2, OP3. ), And the second pulse (before wavelength conversion) P2a, which is a pulse having a phase difference of 120 degrees, is output.

The wavelength change unit (PPLN) 14 receives the traveling light (the second pulse P2a) that has traveled through each of the plurality of optical paths OP1, OP2, and OP3, changes the wavelengths to different wavelengths, and outputs the light. The output of the wavelength changing unit 14 is the second pulse (after wavelength conversion) P2b.

With reference to FIG. 7, the wavelength changing unit 14 receives the second pulse P2a that has advanced the optical path OP1 (wavelength W1 [nm]) and converts it into the second pulse P2b (wavelength W2 [nm]). .. Further, the wavelength changing unit 14 receives the second pulse P2a that has advanced the optical path OP2 (wavelength W1 [nm]) and converts it into the second pulse P2b (wavelength W3 [nm]). Further, the wavelength changing unit 14 receives the second pulse P2a that has advanced the optical path OP3 (wavelength W1 [nm]) and converts it into the second pulse P2b (wavelength W4 [nm]).

The configuration of the wavelength changing unit 14 is the same as that of the first embodiment and its modifications (see FIGS. 2 and 4). However, further, the polarization inversion portion 144 in which the second pulse P2a traveling through the optical path OP3 propagates is arranged at a predetermined interval D3 (however, D3 is different from D1 and D2).

The mirror 154 receives the second pulse (after wavelength conversion) P2b that has traveled through the optical path OP3 and reflects it toward the dichroic mirror 162.

The dichroic mirror (combiner) (DCM) 162 is the second pulse (after wavelength conversion) P2b that has traveled through the optical path OP2 and the reflected light from the mirror 154 (second pulse (after wavelength conversion) P2b). Of these, the one that has advanced in the optical path OP3) is combined and reflected toward the dichroic mirror 164.

The dichroic mirror (combiner) (DCM) 164 is the second pulse (after wavelength conversion) P2b that has traveled through the optical path OP1 and the light from the dichroic mirror 162 (second pulse (after wavelength conversion) P2b). Of these, the one that has traveled through the optical path OP2 and the one that has traveled through the optical path OP3 are combined), and the third pulse (before filtering) P3a having a predetermined frequency (2 kHz) is output.

Next, the operation of the third embodiment will be described.

First, the excitation laser 10 outputs a laser beam having a predetermined wavelength W1 [nm] as a first pulse P1 (see FIG. 7) having a predetermined frequency (for example, 2 kHz). The first pulse P1 is attenuated by the optical attenuator 11 and then given to the acoustic-optical deflector 120. The timing control circuit 19 controls the output timing (see FIG. 7) of the acoustic-optical deflector 120.

When the acoustic-optical deflector 120 receives the 1 + 3Nth (1, 4, 7, ...) Pulse of the first pulse P1, no acoustic wave is applied to the acoustic-optical deflector 120. As a result, the 1 + 3Nth pulse of the first pulse P1 passes straight through the acoustic-optical deflector 120 (optical path OP1). Therefore, the traveling light traveling in the optical path OP1 has a second pulse (before wavelength conversion) having a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3). It becomes P2a.

When the acoustic-optical deflector 120 receives the 2 + 3Nth (2nd, 5th, 8th, ...) Pulse of the first pulse P1, the acoustic optical deflector 120 is given an acoustic wave (angular frequency ω2). As a result, the 2 + 3Nth pulse of the second pulse P1 passes through the acoustic-optical deflector 120 while diffracting to some extent (optical path OP2). Therefore, the traveling light traveling in the optical path OP2 has a second pulse (before wavelength conversion) having a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3). It becomes P2a.

When the acoustic-optical deflector 120 receives the 3 + 3Nth (3, 6, 9, ...) Pulse of the first pulse P1, an acoustic wave (angular frequency ω3) is applied to the acoustic-optical deflector 120. As a result, the 3 + 3Nth pulse of the second pulse P1 passes through the acoustic-optical deflector 120 while diffracting to some extent (optical path OP3). Therefore, the traveling light traveling in the optical path OP3 has a second pulse (before wavelength conversion) having a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3). It becomes P2a.

Moreover, the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP1 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP2 are different by 120 degrees. The phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP2 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP3 are different by 120 degrees. The phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP1 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP3 are different by 240 degrees.

The traveling light traveling through the optical path OP1 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) propagates in the polarization inversion portion 144 arranged at a predetermined interval D1 in the wavelength change portion 14. The wavelength is converted to W2 [nm] to become the second pulse (after wavelength conversion) P2b, which is given to the dichroic mirror 164.

The traveling light traveling through the optical path OP2 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) propagates in the polarization inversion portion 144 arranged at a predetermined interval D2 in the wavelength change portion 14. The wavelength is converted to W3 [nm] to become the second pulse (after wavelength conversion) P2b, which is reflected by the dichroic mirror 162 and then given to the dichroic mirror 164.

The traveling light traveling through the optical path OP3 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) propagates in the polarization inversion portion 144 arranged at a predetermined interval D2 in the wavelength change portion 14. The wavelength is converted to W4 [nm], becomes the second pulse (after wavelength conversion) P2b, is reflected by the mirror 154, and is then given to the dichroic mirror 164 via the dichroic mirror 162.

Of the second pulse (after wavelength conversion) P2b output by the wavelength change unit 14, the wavelength W2 [nm], the wavelength W3 [nm], and the wavelength W4 [nm] are obtained by the dichroic mirror 164. It is combined and becomes a third pulse (before filtering) P3a having a predetermined frequency (2 kHz).

The third pulse (before filtering) P3a becomes the third pulse (after filtering) P3b after the pump light and idler light are removed by the filter 17. The third pulse (after filtering) P3b is given to one end of the optical fiber 18 and output from the other end.

According to the third embodiment, since the acousto-optic deflector 120 is used instead of the acousto-optic modulator 12, the plurality of optical paths can be increased to three (optical paths OP1, OP2, OP3). As a result, the third pulse (after filtering) P3b is immediately (for example, 500 microseconds) irradiated with pulsed light having another wavelength W3 [nm] after being irradiated with pulsed light having a wavelength W2 [nm]. .. Moreover, immediately after the pulsed light of the wavelength W3 [nm] is irradiated (for example, 500 microseconds), the pulsed light of yet another wavelength W4 [nm] is irradiated. That is, according to the third embodiment, it is possible to irradiate the pulsed light of a certain wavelength, immediately irradiate the pulsed light of another wavelength, and immediately irradiate the pulsed light of another wavelength. As described above, according to the third embodiment, it is possible to irradiate pulsed light having three kinds of wavelengths.

In the third embodiment, the plurality of optical paths is described as three, but four or more may be used. This makes it possible to irradiate pulsed light having four or more wavelengths.

Further, in the third embodiment, as in the first embodiment, there is only one LN crystal substrate 142, and all of the polarization inversion portions 144 are formed. However, as in the second embodiment, the LN crystal substrate may be provided for each propagating traveling light (one in which the optical path OP1 is advanced, one in which the optical path OP2 is advanced, and one in which the optical path OP3 is advanced). ..

Fourth Embodiment The laser light output device 1 according to the fourth embodiment has an optical path determination unit (first acousto-optic modulator (AOM) 12a) instead of the acoustic optical deflector (AOD) (optical path determination unit) 120. And the point that the second acousto-optic modulator (AOM) 12b) is used is mainly different from the laser light output device 1 according to the third embodiment.

FIG. 8 is a diagram showing the configuration of the laser light output device 1 according to the fourth embodiment. FIG. 9 is an enlarged view of the vicinity of the optical path determination unit (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator (AOM) 12b) in the laser light output device 1 according to the fourth embodiment. ..

The laser light output device 1 according to the fourth embodiment includes an excitation laser (pulse laser output unit) 10, light attenuators (ATT) 11a, 11b, 11c, a first acousto-optic modulator (AOM) 12a, and a second sound. Optical modulator (AOM) 12b, longoid prisms 13a, 13b, wavelength changers (PPLN) 14a, 14b, 14c, mirror 154, dichroic mirror (combiner) (DCM) 162, 164, filter (F) 172, It includes 174, 176, an optical fiber (MMF) 18, a timing control circuit (timing control unit) 19, and a lens (L) 192. Hereinafter, the same parts as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

The third embodiment includes an excitation laser (pulse laser output unit) 10, a mirror 154, a dichroic mirror (combiner) (DCM) 162, 164, an optical fiber (MMF) 18, and a timing control circuit (timing control unit) 19. The same applies to the above, and the description thereof will be omitted. However, the optical fiber (MMF) 18 receives the third pulse P3 output by the dichroic mirror 164 at one end thereof via the lens (L) 192 and outputs the third pulse P3 from the other end. Further, the timing control circuit 19 controls the output timing (see P2a of FIG. 7) of the optical path determination unit (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator (AOM) 12b).

The optical path determination unit includes a first acousto-optic modulator (AOM) 12a and a second acousto-optic modulator (AOM) 12b. The planar shapes of the first acousto-optic modulator (AOM) 12a and the second acousto-optic modulator (AOM) 12b are both rectangular.

The longer side of the first acousto-optic modulator (AOM) 12a receives the first pulse P1. The shorter side of the first acousto-optic modulator (AOM) 12a is tilted counterclockwise by θB (Bragg angle) with respect to the optical path OP2.

The longer side of the second acousto-optic modulator (AOM) 12b receives the output of the first acousto-optic modulator 12a. The shorter side of the second acousto-optic modulator (AOM) 12b is tilted clockwise by θB (Bragg angle) with respect to the optical path OP2.

The first acousto-optic modulator (AOM) 12a receives the first pulse P1 and determines and outputs an optical path to one of a plurality of optical paths OP1 and OP2 for each of the first pulses P1. In the fourth embodiment, the first acousto-optic modulator (AOM) 12a outputs each of the first pulses P1 by diffracting (optical path OP1) or going straight (optical path OP2).

The second acousto-optic modulator (AOM) 12b receives the output of the first acousto-optic modulator 12a, and for each pulse of the output of the first acousto-optic modulator 12a, one or more optical paths OP1, OP2, OP3. The optical path is determined for one of them and output. In the fourth embodiment, the second acousto-optic modulator (AOM) 12b receives the first pulse traveling straight (optical path OP2), diffracts it (optical path OP3) or travels straight (optical path OP2), and outputs it. The first pulse is diffracted (optical path OP1) and travels straight (optical path OP1) for output.

The first pulse P1, the second pulse (before wavelength conversion) P2a, the second pulse (after wavelength conversion) P2b, and the third pulse P3 (input to the optical fiber (MMF) 18) according to the fourth embodiment. The timing chart is the same as in FIG. 7 (however, P3b in FIG. 7 shall be read as P3).

For example, referring to FIGS. 9 and 7, when the optical path determination unit receives the 1 + 3Nth (1, 4, 7, ...) (where N is an integer of 0 or more) pulse of the first pulse P1. , The first acousto-optic modulator (AOM) 12a is given an acoustic wave, and the second acousto-optic modulator (AOM) 12b is not given an acoustic wave. Then, the 1 + 3Nth pulse of the first pulse P1 advances in the optical path OP1 (see FIG. 9).

Further, when the optical path determination unit receives the 2 + 3Nth (2nd, 5th, 8th, ...) Pulse of the first pulse P1, the first acousto-optic modulator (AOM) 12a also has the second acousto-optic modulator. No acoustic wave is given to (AOM) 12b either. Then, the 2 + 3Nth pulse of the first pulse P1 advances in the optical path OP2 (see FIG. 9).

Further, when the optical path determining unit receives the 3 + 3Nth (3rd, 6th, 9th, ...) Pulse of the first pulse P1, no acoustic wave is applied to the first acousto-optic modulator (AOM) 12a, and the first pulse is not applied. An acoustic wave is applied to the acousto-optic modulator (AOM) 12b. Then, the 3 + 3Nth pulse of the first pulse P1 advances in the optical path OP3 (see FIG. 9).

As a result, the optical path determination unit obtains a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3) from each of the plurality of optical paths OP1, OP2, OP3. It outputs the second pulse (before wavelength conversion) P2a, which is a pulse having 120 degrees different in phase.

The romvoid prism 13a receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP1 and changes the optical path so as to be parallel to the optical path and away from the optical path OP1. The romvoid prism 13b receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP3, and changes the optical path so as to be parallel to the optical path and away from the optical path OP3.

The optical attenuators (ATT) 11a, 11b, 11c emit light traveling through the optical path OP1 (output of the romvoid prism 13a), light traveling through the optical path OP2, and light traveling through the optical path OP3 (output of the romvoid prism 13b). It is attenuated and applied to the wavelength change parts (PPLN) 14a, 14b, 14c.

The wavelength changing units (PPLN) 14a and 14b are the same as those in the second embodiment, and the description thereof will be omitted. The wavelength change unit (PPLN) 14c receives the second pulse P2a traveling through the optical path OP3 (wavelength W1 [nm]) from the romvoid prism 13b and converts it into the second pulse P2b (wavelength W4 [nm]). To do. The configuration of the wavelength changing portion 14b is such that the polarization reversing portion 144 is arranged at a predetermined interval D2 (however, the predetermined interval D2 is changed to D3) in FIG. 2 or FIG. Corresponds to the LN crystal substrate 142.

The LN crystal substrate of the wavelength changing unit 14a, the LN crystal substrate of the wavelength changing unit 14b, and the LN crystal substrate of the wavelength changing unit 14c are different from each other. That is, the LN crystal substrate of the wavelength change unit 14a, the LN crystal substrate of the wavelength change unit 14b, and the LN crystal substrate of the wavelength change unit 14c are propagating traveling light (the one that has advanced the optical path OP1 and the optical path). It is provided for each of the one that has advanced OP2 and the one that has advanced the optical path OP3).

Filters (F) 172, 174, 176 remove pump light and idler light from the outputs of wavelength changers (PPLN) 14a, 14b, 14c to dichroic mirrors (DCM) 164, 162, Output to mirror 154.

The lens (L) 192 receives the output of the dichroic mirror (combiner) (DCM) 164 and supplies it to the optical fiber (MMF) 18.

Next, the operation of the fourth embodiment will be described.

First, the excitation laser 10 outputs a laser beam having a predetermined wavelength W1 [nm] as a first pulse P1 (see FIG. 7) having a predetermined frequency (for example, 2 kHz). The first pulse P1 is given to the first acousto-optic modulator (AOM) 12a of the optical path determination unit. The timing control circuit 19 controls the output timing of the optical path determination unit (see P2a in FIG. 7).

When the optical path determination unit receives the 1 + 3Nth (1, 4, 7, ...) pulse of the first pulse P1 (however, N is an integer of 0 or more), the first acousto-optic modulator (AOM) 12a is used. An acoustic wave is applied, and no acoustic wave is applied to the second acousto-optic modulator (AOM) 12b. Then, the 1 + 3Nth pulse of the first pulse P1 advances in the optical path OP1 (see FIG. 9). Therefore, the traveling light traveling in the optical path OP1 has a second pulse (before wavelength conversion) having a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3). It becomes P2a (see FIG. 7).

When the optical path determination unit receives the 2 + 3Nth (2nd, 5th, 8th, ...) Pulse of the first pulse P1, the first acousto-optic modulator (AOM) 12a also has the second acousto-optic modulator (AOM). ) No acoustic wave is given to 12b either. Then, the 2 + 3Nth pulse of the first pulse P1 advances in the optical path OP2 (see FIG. 9). Therefore, the traveling light traveling in the optical path OP2 has a second pulse (before wavelength conversion) having a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3). It becomes P2a (see FIG. 7).

When the optical path determination unit receives the 3 + 3Nth (3rd, 6th, 9th, ...) pulse of the first pulse P1, no acoustic wave is given to the first acousto-optic modulator (AOM) 12a, and the second acoustic An acoustic wave is applied to the optical modulator (AOM) 12b. Then, the 3 + 3Nth pulse of the first pulse P1 advances in the optical path OP3 (see FIG. 9). Therefore, the traveling light traveling in the optical path OP3 has a second pulse (before wavelength conversion) having a frequency (2/3 kHz) obtained by dividing a predetermined frequency (for example, 2 kHz) by the number of a plurality of optical paths (3). It becomes P2a (see FIG. 7).

Moreover, the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP1 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP2 are different by 120 degrees. The phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP2 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP3 are different by 120 degrees. The phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP1 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP3 are different by 240 degrees.

The traveling light traveling through the optical path OP1 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) has its optical path changed by the romvoid prism 13a and attenuated by the optical attenuator (ATT) 11a to have a wavelength. It is given to the change part (PPLN) 14a. Further, the light given to the wavelength changing unit (PPLN) 14a propagates through the polarization inversion unit 144 arranged at a predetermined interval D1 in the wavelength changing unit 14a, and the wavelength is converted to W2 [nm]. It becomes the second pulse (after wavelength conversion) P2b, and after the pump light and idler light are removed by the filter (F) 172, it is given to the dichroic mirror 164.

The traveling light traveling through the optical path OP2 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) is attenuated by the optical attenuator (ATT) 11b and given to the wavelength change unit (PPLN) 14b. Further, the light given to the wavelength changing part (PPLN) 14b propagates through the polarization inversion part 144 arranged at a predetermined interval D2 in the wavelength changing part 14b, and the wavelength is converted to W3 [nm]. It becomes the second pulse (after wavelength conversion) P2b, the pump light and the idler light are removed by the filter (F) 174, reflected by the dichroic mirror 162, and then given to the dichroic mirror 164.

The traveling light traveling through the optical path OP3 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) has its optical path changed by the romvoid prism 13b and attenuated by the optical attenuator (ATT) 11c. It is given to the change part (PPLN) 14c. Further, the light given to the wavelength changing unit (PPLN) 14c propagates through the polarization inversion unit 144 arranged at a predetermined interval D3 in the wavelength changing unit 14a, and the wavelength is converted to W4 [nm]. It becomes the second pulse (after wavelength conversion) P2b, the pump light and the idler light are removed by the filter (F) 176, reflected by the mirror 154, and then given to the dichroic mirror 164 via the dichroic mirror 162.

Of the second pulses (after wavelength conversion) P2b output by the wavelength change units 14a, 14b, and 14c, those with a wavelength of W2 [nm], those with a wavelength of W3 [nm], and those with a wavelength of W4 [nm] are Wavelength is combined by the dichroic mirror 164 to become a third pulse P3 having a predetermined frequency (2 kHz).

The third pulse P3 is transmitted to the optical fiber (MMF) 18 through the lens (L) 192.

According to the fourth embodiment, instead of the acousto-optic deflector 120 in the third embodiment, two acousto-optic modulators (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator ( By using AOM) 12b), it is possible to irradiate pulsed light having three kinds of wavelengths as in the third embodiment. The acousto-optic modulators (two) are easier to mount on the laser light output device 1 than the acousto-optic deflectors, and have the advantages of low cost.

Further, in the fourth embodiment, as in the third embodiment, there is only one LN crystal substrate 142, and all of the polarization inversion portions 144 may be formed.

In the fourth embodiment, the following modifications can be considered for the operation of the optical path determination unit (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator (AOM) 12b).

FIG. 12 shows an enlargement of the vicinity of the optical path determination unit (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator (AOM) 12b) in the laser light output device 1 according to the modified example of the fourth embodiment. It is a figure.

The first acousto-optic modulator (AOM) 12a receives the first pulse P1 and determines and outputs an optical path to one of a plurality of optical paths OP1 and OP2 for each of the first pulses P1. For example, the first acousto-optic modulator (AOM) 12a outputs each of the first pulses P1 by diffracting (optical path OP1) or going straight (optical path OP2). Up to this point, it is the same as the fourth embodiment.

Here, the second acousto-optic modulator (AOM) 12b receives the output of the first acousto-optic modulator 12a, and one or more optical paths OP1 and OP2 for each pulse of the output of the first acousto-optic modulator 12a. , OP3, determines the optical path and outputs it. In the modified example of the fourth embodiment, the second acousto-optic modulator (AOM) 12b receives the first pulse going straight (optical path OP2) and goes straight (optical path OP2) (the fourth point is that it is not diffracted). (Different from the fourth embodiment), the first pulse is diffracted (optical path OP1) and diffracted (optical path OP3) or straight (optical path OP1) (the point that it may be diffracted is different from the fourth embodiment). Output.

The shorter side of the second acousto-optic modulator (AOM) 12b is tilted counterclockwise by θB (Bragg angle) with respect to the optical path OP1.

Fifth Embodiment The laser light output device 1 according to the fifth embodiment has two acousto-optic modulators (first acousto-optic modulator (AOM) 12a and second acousto-optic modulation) as in the fourth embodiment. The point of irradiating pulsed light of four kinds of wavelengths while using the device (AOM) 12b) is mainly different from the laser light output device 1 according to the fourth embodiment.

FIG. 10 is a diagram showing the configuration of the laser light output device 1 according to the fifth embodiment. FIG. 11 is an enlarged view of the vicinity of the optical path determination unit (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator (AOM) 12b) in the laser light output device 1 according to the fifth embodiment. ..

The laser light output device 1 according to the fifth embodiment includes an excitation laser (pulse laser output unit) 10, light attenuators (ATT) 11a, 11b, 11c, 11d, a first acousto-optic modulator (AOM) 12a, and a third. Biacousto-optic modulator (AOM) 12b, longoid prism 13c, 13d, 13e, 13f, wavelength changer (PPLN) 14a, 14b, 14c, 14d, mirror 154, dichroic mirror (combiner) (DCM) 161 It includes 162, 164, a filter (F) 172, 174, 176, 178, an optical fiber (MMF) 18, a timing control circuit (timing control unit) 19, and a lens (L) 192. Hereinafter, the same parts as those in the fourth embodiment are designated by the same reference numerals and the description thereof will be omitted.

Excitation laser (pulse laser output unit) 10, optical attenuator (ATT) 11a, 11b, 11c, wavelength change unit (PPLN) 14a, 14b, 14c, mirror 154, dichroic mirror (combiner) (DCM) 162, 164 , Filter (F) 172, 174, 176, optical fiber (MMF) 18, timing control circuit (timing control unit) 19, and lens (L) 192 are the same as those in the fourth embodiment, and description thereof will be omitted.

However, the mirror 154 receives the second pulse (after wavelength conversion) P2b that has traveled through the optical path OP4 and reflects it toward the dichroic mirror 161. The dichroic mirror (combiner) (DCM) 162 combines the second pulse (after wavelength conversion) P2b, which has traveled in the optical path OP2, with the reflected light from the dichroic mirror 161 to form the dichroic mirror 164. Reflect toward. The filter (F) 176 removes the pump light and the idler light from the output of the wavelength change unit (PPLN) 14c and outputs the light to the dichroic mirror (combiner) (DCM) 161.

The filter (F) 178 removes the pump light and the idler light from the output of the wavelength change unit (PPLN) 14d and outputs the pump light and the idler light to the mirror 154.

The optical path determination unit includes a first acousto-optic modulator (AOM) 12a and a second acousto-optic modulator (AOM) 12b. The planar shapes of the first acousto-optic modulator (AOM) 12a and the second acousto-optic modulator (AOM) 12b are both rectangular.

The long side of the first acousto-optic modulator (AOM) 12a and the long side of the second acousto-optic modulator (AOM) 12b are parallel to each other. The optical path OP4 is tilted clockwise by θB (Bragg angle) with respect to the shorter side of the first acousto-optic modulator (AOM) 12a. The longer side of the first acousto-optic modulator (AOM) 12a receives the first pulse P1, and the longer side of the second acousto-optic modulator (AOM) 12b receives the output of the first acousto-optic modulator 12a. ..

The first acousto-optic modulator (AOM) 12a receives the first pulse P1 and determines and outputs an optical path to one of a plurality of optical paths OP1 and OP4 for each of the first pulses P1. In the fifth embodiment, the first acousto-optic modulator (AOM) 12a outputs each of the first pulses P1 by diffracting (optical path OP1) or going straight (optical path OP4).

The second acousto-optic modulator (AOM) 12b receives the output of the first acousto-optic modulator 12a, and one or more optical paths OP1, OP2, OP3, for each pulse of the output of the first acousto-optic modulator 12a. The optical path is determined and output to any one of OP4. In a fifth embodiment, the second acousto-optic modulator (AOM) 12b diffracts (optical paths OP2, OP3) or straight-ahead (optical path OP2, OP3) or straight ahead (optical path OP2, OP3) for each pulse of the output of the first acousto-optic modulator (AOM) 12a. OP1, OP4) and output. More specifically, the second acousto-optic modulator (AOM) 12b receives the first pulse going straight (optical path OP4), diffracts it (optical path OP2) or goes straight (optical path OP4), and outputs the first pulse. Receives what is diffracted (optical path OP1) and diffracts (optical path OP3) or goes straight (optical path OP1) and outputs it.

When the optical path determination unit receives the 1 + 4Nth (1, 5, 9, ...) Pulse of the first pulse P1 (where N is an integer of 0 or more), the first acousto-optic modulator (AOM) 12a is used. An acoustic wave is applied, and no acoustic wave is applied to the second acousto-optic modulator (AOM) 12b. Then, the 1 + 4Nth pulse of the first pulse P1 advances in the optical path OP1 (see FIG. 11).

Further, when the optical path determination unit receives the 2 + 4Nth (2nd, 6th, 10th, ...) Pulses of the first pulse P1, no acoustic wave is applied to the first acousto-optic modulator (AOM) 12a, and the second pulse An acoustic wave is applied to the acousto-optic modulator (AOM) 12b. Then, the 2 + 4Nth pulse of the first pulse P1 advances in the optical path OP2 (see FIG. 11).

Further, when the optical path determination unit receives the 3 + 4Nth (3rd, 7th, 11th, ...) Pulse of the first pulse P1, an acoustic wave is applied to the first acousto-optic modulator (AOM) 12a to provide the second acoustic. An acoustic wave is also applied to the optical modulator (AOM) 12b. Then, the 3 + 4Nth pulse of the first pulse P1 advances in the optical path OP3 (see FIG. 11).

Further, when the optical path determination unit receives the 4 + 4Nth (4th, 8th, 12th, ...) Pulse of the first pulse P1, no acoustic wave is applied to the first acousto-optic modulator (AOM) 12a, and the first pulse is No acoustic wave is applied to the acousto-optic modulator (AOM) 12b. Then, the 4 + 4Nth pulse of the first pulse P1 advances in the optical path OP4 (see FIG. 11).

As a result, the optical path determination unit determines the frequency (1 / 2kHz) obtained by dividing a predetermined frequency (for example, 2kHz) by the number of the plurality of optical paths (4) from each of the plurality of optical paths OP1, OP2, OP3, and OP4. ), And the second pulse (before wavelength conversion) P2a, which is a pulse whose phase is different by 90 degrees, is output.

The romvoid prism 13c receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP1 and changes the optical path so as to be parallel to the optical path and away from the optical path OP1. The romvoid prism 13e receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP2, and changes the optical path so as to be parallel to the optical path and away from the optical path OP2. The romvoid prism 13f receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP3, and changes the optical path so as to be parallel to the optical path and away from the optical path OP3. The romvoid prism 13d receives the second pulse (before wavelength conversion) P2a that has traveled through the optical path OP4, and changes the optical path so as to be parallel to the optical path and away from the optical path OP4.

The optical attenuator (ATT) 11d attenuates the light traveling through the optical path OP4 (the output of the longoid prism 13d) and gives it to the wavelength change unit (PPLN) 14d.

The wavelength change unit (PPLN) 14d receives the second pulse P2a traveling through the optical path OP4 (wavelength W1 [nm]) from the romvoid prism 13d and converts it into the second pulse P2b (wavelength W5 [nm]). To do. The configuration of the wavelength changing unit 14b is arranged with a predetermined interval D2 (however, the predetermined interval D2 is changed to D4 different from any of D1, D2, and D3) in FIG. 2 or FIG. It corresponds to the polarization inversion portion 144 and the LN crystal substrate 142 on which it is formed.

The LN crystal substrate of the wavelength changing unit 14a, the LN crystal substrate of the wavelength changing unit 14b, the LN crystal substrate of the wavelength changing unit 14c, and the LN crystal substrate of the wavelength changing unit 14d are different. is there. That is, the LN crystal substrate of the wavelength changing unit 14a, the LN crystal substrate of the wavelength changing unit 14b, the LN crystal substrate of the wavelength changing unit 14c, and the LN crystal substrate of the wavelength changing unit 14d propagate. It is provided for each light (one in which the optical path OP1 is advanced, one in which the optical path OP2 is advanced, one in which the optical path OP3 is advanced, and one in which the optical path OP4 is advanced).

Next, the operation of the fifth embodiment will be described.

First, the excitation laser 10 outputs a laser beam having a predetermined wavelength W1 [nm] as a first pulse P1 having a predetermined frequency (for example, 2 kHz). The first pulse P1 is given to the first acousto-optic modulator (AOM) 12a of the optical path determination unit. The timing control circuit 19 controls the output timing of the optical path determination unit.

When the optical path determination unit receives the 1 + 4Nth (1, 5, 9, ...) Pulse of the first pulse P1 (where N is an integer of 0 or more), the first acousto-optic modulator (AOM) 12a is used. An acoustic wave is applied, and no acoustic wave is applied to the second acousto-optic modulator (AOM) 12b. Then, the 1 + 4Nth pulse of the first pulse P1 advances in the optical path OP1 (see FIG. 11). Therefore, the traveling light traveling in the optical path OP1 has a second pulse (before wavelength conversion) having a frequency (1 / 2kHz) obtained by dividing a predetermined frequency (for example, 2kHz) by the number of a plurality of optical paths (4). It becomes P2a.

When the optical path determination unit receives the 2 + 4Nth (2nd, 6th, 10th, ...) pulse of the first pulse P1, no acoustic wave is applied to the first acousto-optic modulator (AOM) 12a, and the second acousto-optics An acoustic wave is applied to the modulator (AOM) 12b. Then, the 2 + 4Nth pulse of the first pulse P1 travels in the optical path OP2 (see FIG. 11). Therefore, the traveling light traveling in the optical path OP2 has a second pulse (before wavelength conversion) having a frequency (1 / 2kHz) obtained by dividing a predetermined frequency (for example, 2kHz) by the number of a plurality of optical paths (4). It becomes P2a.

When the optical path determination unit receives the 3 + 4Nth (3rd, 7th, 11th, ...) pulse of the first pulse P1, an acoustic wave is applied to the first acousto-optic modulator (AOM) 12a to perform the second acousto-optic modulation. An acoustic wave is also applied to the vessel (AOM) 12b. Then, the 3 + 4Nth pulse of the first pulse P1 advances in the optical path OP3 (see FIG. 11). Therefore, the traveling light traveling in the optical path OP3 has a second pulse (before wavelength conversion) having a frequency (1 / 2kHz) obtained by dividing a predetermined frequency (for example, 2kHz) by the number of a plurality of optical paths (4). It becomes P2a.

When the optical path determination unit receives the 4 + 4Nth (4th, 8th, 12th, ...) pulse of the first pulse P1, no acoustic wave is given to the first acousto-optic modulator (AOM) 12a, and the second acoustic No acoustic wave is applied to the optical modulator (AOM) 12b. Then, the 4 + 4Nth pulse of the first pulse P1 advances in the optical path OP4 (see FIG. 11). Therefore, the traveling light traveling in the optical path OP4 has a second pulse (before wavelength conversion) having a frequency (1 / 2kHz) obtained by dividing a predetermined frequency (for example, 2kHz) by the number of a plurality of optical paths (4). It becomes P2a.

Moreover, the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP1 and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP2 and the optical path OP3 are advanced. The phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling and the phase of the traveling light (second pulse (before wavelength conversion) P2a) traveling in the optical path OP4 are different by 90 degrees.

The traveling light (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) traveling in the optical path OP1 has its optical path changed by the romvoid prism 13c and attenuated by the optical attenuator (ATT) 11a to have a wavelength. It is given to the change part (PPLN) 14a. Further, the light given to the wavelength changing unit (PPLN) 14a propagates through the polarization inversion unit 144 arranged at a predetermined interval D1 in the wavelength changing unit 14a, and the wavelength is converted to W2 [nm]. It becomes the second pulse (after wavelength conversion) P2b, and after the pump light and idler light are removed by the filter (F) 172, it is given to the dichroic mirror 164.

The traveling light (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) traveling in the optical path OP2 has its optical path changed by the romvoid prism 13e and attenuated by the optical attenuator (ATT) 11b to have a wavelength. It is given to the change part (PPLN) 14b. Further, the light given to the wavelength changing part (PPLN) 14b propagates through the polarization inversion part 144 arranged at a predetermined interval D2 in the wavelength changing part 14b, and the wavelength is converted to W3 [nm]. It becomes the second pulse (after wavelength conversion) P2b, the pump light and the idler light are removed by the filter (F) 174, reflected by the dichroic mirror 162, and then given to the dichroic mirror 164.

The traveling light traveling in the optical path OP3 (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) has its optical path changed by the romvoid prism 13f and attenuated by the optical attenuator (ATT) 11c to have a wavelength. It is given to the change part (PPLN) 14c. Further, the light given to the wavelength changing part (PPLN) 14c propagates through the polarization inversion part 144 arranged at a predetermined interval D3 in the wavelength changing part 14c, and the wavelength is converted to W4 [nm]. It becomes the second pulse (after wavelength conversion) P2b, the pump light and the idler light are removed by the filter (F) 176, reflected by the dichroic mirror 161 and then given to the dichroic mirror 164 via the dichroic mirror 162.

The traveling light (second pulse (before wavelength conversion) P2a: wavelength W1 [nm]) traveling in the optical path OP4 has its optical path changed by the romvoid prism 13d and attenuated by the optical attenuator (ATT) 11d to have a wavelength. It is given to the change part (PPLN) 14d. Further, the light given to the wavelength changing portion (PPLN) 14d propagates through the polarization inversion portion 144 arranged at a predetermined interval D4 in the wavelength changing portion 14d, and the wavelength is converted to W5 [nm]. It becomes the second pulse (after wavelength conversion) P2b, the pump light and the idler light are removed by the filter (F) 178, reflected by the mirror 154, and then given to the dichroic mirror 164 via the dichroic mirrors 161 and 162.

Of the second pulses (after wavelength conversion) P2b output by the wavelength changing units 14a, 14b, 14c, 14d, those having a wavelength of W2 [nm], those having a wavelength of W3 [nm], and those having a wavelength of W4 [nm]. And the wavelength W5 [nm] are combined by the dichroic mirror 164 to form a third pulse P3 having a predetermined frequency (2 kHz).

The third pulse P3 is transmitted to the optical fiber (MMF) 18 through the lens (L) 192.

According to the fifth embodiment, as in the fourth embodiment, while using two acousto-optic modulators (first acousto-optic modulator (AOM) 12a and second acousto-optic modulator (AOM) 12b). , It is possible to irradiate pulsed light of four kinds of wavelengths, which is larger than that of the fourth embodiment.

Further, in the fifth embodiment, as in the third embodiment, there is only one LN crystal substrate 142, and all of the polarization inversion portions 144 may be formed.

Sixth Embodiment The sixth embodiment is a photoacoustic wave measuring device using the laser light output device 1 according to the first, second, third, fourth and fifth embodiments (including modifications). It is about 100.

FIG. 13 is a functional block diagram showing the configuration of the photoacoustic wave measuring device 100 according to the sixth embodiment of the present invention.

The photoacoustic wave measuring device 100 according to the sixth embodiment is for measuring a measurement target 200 (for example, a new blood vessel in the vicinity of a basal cell carcinoma up to a depth of about 3 mm in the human body, but is not limited thereto). It is provided with a laser light output device 1 and a measuring unit 4.

The laser light output device 1 is the same as the laser light output device 1 according to the first, second, third, fourth and fifth embodiments (including modifications). However, in the laser light PL output by the laser light output device 1, the third pulse (after filtering) P3b in the first, second, third, fourth and fifth embodiments (including modifications) is an optical fiber. It has passed through 18. The laser light output device 1 gives the measurement unit 4 a trigger signal synchronized with the time when the pulse in the laser light PL is output.

The measurement unit 4 measures the measurement target 200 based on the photoacoustic wave AW generated in the measurement target 200 by the laser light PL. The measurement unit 4 performs measurement synchronized with the trigger signal given by the laser light output device 1.

Next, the operation of the sixth embodiment will be described.

The laser light output device 1 outputs the laser light PL. The laser beam PL is the same as that of the third pulse (after filtering) P3b.

The laser beam PL is given to the measurement target 200. When the laser beam PL is applied to the measurement target 200, a photoacoustic wave AW is generated.

The measurement target 200 is measured by the measuring unit 4 based on the photoacoustic wave AW.

According to the sixth embodiment, by giving the laser light PL to the measurement target 200, the measurement target 200 can measure the photoacoustic wave. Moreover, irradiating the measurement target 200 with pulsed light of a certain wavelength and then immediately irradiating the pulsed light of another wavelength is the first, second, third, fourth, and fifth embodiment. It is possible as well.

Seventh Embodiment In the seventh embodiment, the laser light output device 1 and the ultrasonic pulse output unit 2 according to the first, second, third, fourth and fifth embodiments (including modified examples) are provided. It relates to the photoacoustic wave measuring apparatus 100 used.

FIG. 14 is a functional block diagram showing the configuration of the photoacoustic wave measuring device 100 according to the seventh embodiment of the present invention.

The photoacoustic wave measuring device 100 according to the seventh embodiment is for measuring a measurement target 200 (for example, a new blood vessel in the vicinity of a basal cell cancer up to a depth of about 3 mm in the human body, but is not limited thereto). It includes a laser light output device 1, an ultrasonic pulse output unit 2, and a measurement unit 4.

The laser light output device 1 is the same as the laser light output device 1 according to the first, second, third, fourth and fifth embodiments (including modifications). However, in the laser light PL output by the laser light output device 1, the third pulse (after filtering) P3b in the first, second, third, fourth and fifth embodiments (including modifications) is an optical fiber. It has passed through 18. The laser light output device 1 gives the measurement unit 4 a trigger signal synchronized with the time when the pulse in the laser light PL is output.

The ultrasonic pulse output unit 2 outputs an ultrasonic pulse PU. The ultrasonic pulse output unit 2 gives the measurement unit 4 a trigger signal synchronized with the time when the pulse in the ultrasonic pulse PU is output.

The measuring unit 4 measures the measurement target 200 based on the reflected wave US reflected by the ultrasonic pulse PU and the photoacoustic wave AW generated in the measurement target 200 by the laser beam PL. The measurement unit 4 performs measurement synchronized with the trigger signal given by the laser light output device 1 and the ultrasonic pulse output unit 2.

Next, the operation of the seventh embodiment will be described.

The laser light output device 1 outputs the laser light PL. The laser beam PL is the same as that of the third pulse (after filtering) P3b. The ultrasonic pulse output unit 32 outputs an ultrasonic pulse PU.

The laser light PL and the ultrasonic pulse PU are given to the measurement target 200. When the laser beam PL is applied to the measurement target 200, a photoacoustic wave AW is generated. When the ultrasonic pulse PU is applied to the measurement target 200, it is reflected. This reflected wave is the reflected wave US.

The measurement target 200 is measured by the measuring unit 4 based on the reflected wave US and the photoacoustic wave AW.

According to the seventh embodiment, the measurement target 200 can be measured by optical ultrasonic waves by giving the laser light PL and the ultrasonic pulse PU to the measurement target 200. Moreover, irradiating the measurement target 200 with pulsed light of a certain wavelength and then immediately irradiating the pulsed light of another wavelength is the first, second, third, fourth, and fifth embodiment. It is possible as well.

P1 1st pulse P2a 2nd pulse (before wavelength conversion)
P2b second pulse (after wavelength conversion)
P3a 3rd pulse (before filtering)
P3b 3rd pulse (after filtering)
OP1, OP2, OP3 Optical path 1 Laser light output device 10 Excitation laser (pulse laser output unit)
11 Optical Attenuator (ATT)
12 Acousto-optic modulator (optical path determination unit) (AOM)
120 Acoustic Optical Deflector (AOD) (Optical Path Determination Unit)
13 Ronvoid prism 14, 14a, 14b Wavelength change part (PPLN)
142 LN crystal substrate 144 Polarization inversion part 15, 154 Mirror 16, 162, 164 Dichroic mirror (combiner) (DCM)
17 Filter (F)
18 Optical fiber (MMF)
2 Ultrasonic pulse output unit 4 Measuring unit 100 Photoacoustic wave measuring device 200 Measurement target

Claims (18)

A laser light output device that outputs laser light and
A measuring unit that measures the measurement target based on the photoacoustic wave generated in the measurement target by the laser light,
With
The laser light output device
A pulsed laser output unit that outputs laser light of a predetermined wavelength as the first pulse,
An optical path determination unit that receives the first pulse, determines an optical path for each of the first pulses in any one of a plurality of optical paths, and outputs the optical path.
A wavelength change unit that receives traveling light traveling through each of the plurality of optical paths, changes the wavelength to a different wavelength, and outputs the light.
With a combiner that combines the output of the wavelength change section,
Photoacoustic wave measuring device having. The photoacoustic wave measuring device according to claim 1.
Equipped with an ultrasonic pulse output unit that outputs ultrasonic pulses
The measuring unit further measures the reflected wave reflected by the ultrasonic pulse on the measurement target.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 1 or 2.
The first pulse has a predetermined frequency and
The optical path determination unit outputs a second pulse from each of the plurality of optical paths, which is a pulse having a frequency obtained by dividing the predetermined frequency by the number of the plurality of optical paths and having different phases.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 3.
The combiner outputs a third pulse having the predetermined frequency.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to any one of claims 1 to 4.
The pulsed laser output unit is an excitation laser.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to any one of claims 1 to 4.
The optical path determining unit is an acousto-optic modulator or an acoustic-optical deflector.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to any one of claims 1 to 4.
The wavelength change part
The traveling light propagates and has polarization inversion portions arranged at predetermined intervals.
The predetermined interval differs for each traveling light.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 7.
The wavelength change part
It has a nonlinear optical crystal substrate on which the polarization inversion portion is formed, and has
The centroid of the polarization inversion portion is arranged on a straight line parallel to the x-axis of the nonlinear optical crystal substrate.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 7.
The center of gravity of the polarization inversion portion is arranged on a straight line parallel to the traveling direction of the traveling light.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 7.
A photoacoustic wave measuring device in which the wavelength changing portion has one nonlinear optical crystal substrate in which all of the polarization inversion portions are formed. The photoacoustic wave measuring device according to claim 7.
The wavelength change part
It has a nonlinear optical crystal substrate on which the polarization inversion portion is formed, and has
The nonlinear optical crystal substrate is provided for each propagating traveling light.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to any one of claims 1 to 4.
The wavelength change portion has a nonlinear optical crystal through which the traveling light propagates.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to any one of claims 1 to 4.
A photoacoustic wave measuring device including an optical fiber that receives the output of the combiner at one end and outputs it from the other end. The photoacoustic wave measuring device according to any one of claims 1 to 4.
A photoacoustic wave measuring device including a timing control unit that matches the output of the optical path determination unit with the timing of the output of the first pulse. The photoacoustic wave measuring device according to any one of claims 1 to 14.
The optical path determination unit
A first acousto-optic modulator that receives the first pulse and determines and outputs an optical path to any one of a plurality of optical paths for each of the first pulses.
The second acousto-optic modulation that receives the output of the first acousto-optic modulator and determines and outputs an optical path to any one of one or more optical paths for each pulse of the output of the first acousto-optic modulator. With a vessel
Photoacoustic wave measuring device having. The photoacoustic wave measuring device according to claim 15.
The first acousto-optic modulator outputs each of the first pulses by diffracting or traveling straight.
The second acousto-optic modulator receives the first pulse in a straight line and diffracts or straightens it to output, and receives the first pulse diffracted in a straight line and outputs it.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 15.
The first acousto-optic modulator outputs each of the first pulses by diffracting or traveling straight.
The second acousto-optic modulator receives what the first pulse has diffracted and diffracts or travels straight to output, and receives what the first pulse has traveled straight to output.
Photoacoustic wave measuring device. The photoacoustic wave measuring device according to claim 15.
The first acousto-optic modulator outputs each of the first pulses by diffracting or traveling straight.
The second acousto-optic modulator outputs each pulse of the output of the first acousto-optic modulator by diffracting or traveling straight.
Photoacoustic wave measuring device.

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