JP2018105983A - Light source device, and optical analyzer equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source for an optical analyzer that makes light of a band necessary for irradiation of a sample available without using a separate filter, and can reduce intensity of a band of an infrared ray.SOLUTION: A light source device has: a photonic crystal fiber (PCF) that converts ultrashort pulse light into super-continuum light (SC light) to emit the SC light; and a first optical system upon which the SC light is incident. The PCF, which has: a core part; and a plurality of hole parts that is located on an outer side of the core part, and penetrates in an axial direction of the PCF, has a first clad part that is dispersedly arranged so that the plurality of hole parts covers the core part, having a prescribed interval; and a second clad part that is located on an outer side of the first clad part, has the hole part not formed, and is composed with the same material as that of the core part. The first optical system does not emit, of the SC light, light of a first wavelength band passing through the second clad part and being propagated to a latter stage, and emits light of a second wavelength band of a shorter wavelength than the first wavelength band passing through the core part and being propagated to the latter stage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light source device, and more particularly to a light source device for an optical analyzer using a photonic crystal fiber. The present invention also relates to an optical analyzer provided with this light source device.

  As an apparatus for observing a biological sample, an optical analyzer (fluorescence microscope) using a laser beam as a light source is known.

  The following Patent Document 1 discloses a technique related to an optical analyzer using supercontinuum light (hereinafter, referred to as “SC light” as appropriate). FIG. 11 is a block diagram schematically showing the optical analyzer 100 disclosed in Patent Document 1. As shown in FIG.

  Laser light emitted from the ultrashort pulse laser light source 101 is coupled to the photonic crystal fiber 103 by the condenser lens 102 and converted into broadband SC light inside the photonic crystal fiber 103. The SC light is converted into parallel light by the collimator lens 104 and then incident on the long pass filter 105, and a component having a wavelength shorter than the wavelength of the laser light emitted from the ultrashort pulse laser light source 101 is blocked. As an example of the laser light emitted from the ultrashort pulse laser light source 101, the center wavelength is 1064 nm, the pulse width is 900 ps, the repetition frequency is 30 kHz, and the average output is 200 mW.

  That is, the light transmitted through the long pass filter 105 is composed of a wavelength component of the laser light emitted from the ultrashort pulse laser light source 101 used as the excitation light and a component having a longer wavelength than the excitation light used as the Stokes light component. .

  This light beam is condensed on one point of the sample 107 by the objective lens 106 (NA 0.9, magnification 40 times). Then, coherent anti-Stokes Raman light (hereinafter referred to as “CARS light” as appropriate) reflecting the resonance vibration of the molecules present at the light collection point is emitted from the light collection point of the sample 107. The CARS light is converted into parallel light by the condenser lens 108 (NA 0.65), passes through the short-pass filter 109, blocks the excitation light and Stokes light, which are coaxial components, and then enters the spectroscope 110. The light incident on the spectroscope 110 is split by the spectroscopic unit 111, detected separately for each wavelength by the detecting unit 112, and the spectrum is output as a detection signal.

International Publication No. 2016/063322

  The CARS microscope configured by the optical analyzer 100 can analyze a sample without introducing a fluorescent substance into the sample in advance. Therefore, it is expected to observe the molecular distribution and dynamics in living cells.

  By the way, SC light is light having an extremely wide spectrum and includes, for example, an infrared wavelength component. However, depending on the object to be observed, there is no need for such a broadband light. That is, when the sample is irradiated with SC light, the sample is heated by irradiating the sample with unnecessary infrared component light contained in the SC light, and biological samples such as cells deteriorate due to thermal denaturation. There is a possibility that.

  As a method for solving such a problem, for example, in the apparatus shown in FIG. 11, it is possible to provide a filter (short-pass filter) that cuts unnecessary light in the infrared region before the objective lens 106. However, providing a separate filter increases the number of parts. In addition, it may be difficult to prepare a filter that can effectively cut off only an unnecessary wavelength band. In this case, it is difficult to prevent heating of the sample.

  On the other hand, when a filter that completely blocks an unnecessary wavelength band is prepared to prevent heating, light having a wavelength shorter than this wavelength band is partially blocked due to the nature of the filter. Since this light is light in a wavelength band necessary for observation, the light utilization efficiency is consequently reduced.

  In view of the above problems, the present invention provides a light source device for an optical analyzer that can use light in a band necessary for irradiation of a sample and reduce the intensity of an infrared band without using a separate filter. The purpose is to provide. Another object of the present invention is to provide an optical analyzer including such a light source device.

The light source device according to the present invention includes:
A laser light source that emits ultra-short pulse light;
A photonic crystal fiber that converts the incident ultrashort pulse light into supercontinuum light and emits the light; and
A first optical system on which the supercontinuum light is incident,
The photonic crystal fiber is
A core corresponding to the position closest to the axis of the photonic crystal fiber;
There are a plurality of holes that are located outside the core part and penetrate in the axial direction of the photonic crystal fiber, and the plurality of holes are dispersed so as to cover the core part with a predetermined interval. A first clad portion arranged by
A second clad portion which is located outside the first clad portion, is not formed with the hole portion and is made of the same material as the core portion,
In the first optical system, the light in the first wavelength band propagated through the second cladding portion out of the supercontinuum light is not emitted to the subsequent stage, but is propagated through the core portion. It is the structure which inject | emits the light of the 2nd wavelength band shorter than said 1st wavelength band to a back | latter stage.

  As a result of diligent research by the present inventors, a core part, a first clad part in which a plurality of holes are dispersedly disposed so as to cover the core part, and a second clad part arranged outside the first clad part are provided. In the case of using the photonic crystal fiber having, by appropriately setting the arrangement mode of the hole portion, supercontinuum light, light passing through the core portion, and clad portion (first clad portion or second clad portion) It was newly found that the light can be separated into light passing therethrough. In particular, it has been found that the light passing through the cladding has a longer wavelength than the light passing through the core.

  Therefore, by setting the arrangement mode of the holes, for example, it is possible to pass light in the infrared region unnecessary for sample measurement through the clad part, and to pass light of shorter wavelengths through the core part. Become. For this reason, it is not necessary to separately provide a filter for blocking light on the long wavelength side.

  Under such a configuration, the first optical system is configured so that only the light that has passed through the core portion is emitted to the subsequent stage, so that unnecessary long-wavelength side light is emitted from the light source device to the subsequent optical system. Will not be injected. For this reason, it is suppressed that a sample is heated by irradiating a sample with the light inject | emitted from the 1st optical system. Note that the first wavelength band may be an infrared band, and more specifically, a wavelength band of at least 1600 nm or more.

  The first optical system may include an aperture that allows only light that has passed through the core portion to pass. As another aspect, the first optical system may include a lens that collects only the light that has passed through the core.

  As described above, the core portion corresponds to a position closest to the axial center of the photonic crystal fiber, and the cladding portions (first cladding portion and second cladding portion) correspond to positions outside the core portion. That is, the light in the second wavelength band corresponding to the wavelength band to be used propagates in a position close to the axial center of the photonic crystal fiber. On the other hand, the light in the first wavelength band corresponding to the light in the unnecessary wavelength band propagates in a position outside the core portion in the photonic crystal fiber. For this reason, the first optical system includes an optical member that guides only the light near the center of the light (SC light) emitted from the photonic crystal fiber to the subsequent stage, so that only the light in the second wavelength band can be obtained. Can be injected into the latter stage. Examples of the optical member include the above-described aperture and lens. Such an optical member can be obtained very easily as compared with a filter, and can be blocked in light of the first wavelength band only by positioning with respect to the optical axis, so that the design is simple.

The first cladding part is
The plurality of holes are formed by arranging in a triangular lattice shape,
The row number n of the triangular lattice may be set so that the first wavelength band has a wavelength of at least 1600 nm.

  According to the above configuration, even if a filter is not separately provided, it is not necessary for observation for a fluorescence microscope. Rather, light having a wavelength of 1600 nm or more, which is an undesirable wavelength band, is not emitted to the subsequent stage when the sample is heated. Can do.

The optical analyzer according to the present invention is:
The light source device;
A sample stage on which a sample to be measured is placed;
With a spectroscope,
When the sample is irradiated with light in the first wavelength band emitted from the first optical system, anti-Stokes light emitted from the sample or fluorescence emitted from the sample by multiphoton excitation is reflected in the spectrum. It is incident on the vessel.

  According to the light source device of the present invention, light in a band necessary for irradiation of a sample can be used without using a separate filter, and the intensity can be reduced in the infrared band. For this reason, it can suppress that a sample is heated unnecessarily at the time of observation by using this light source device as a light source device for optical analyzers.

It is a block diagram which shows typically the structure of the light source device of this invention. It is typical sectional drawing when a photonic crystal fiber (PCF) with the number of rows of 7 is cut along a plane perpendicular to the axial direction. It is drawing which shows the structure of a 1st optical system typically. It is drawing which shows the structure of a 1st optical system typically. It is drawing which shows the electromagnetic field analysis of the light which propagates the inside of PCF when d = 0.6 micrometer, d / Λ = 0.3, and n = 7. It is drawing which shows the spectrum of the light inject | emitted from PCF which made d = 0.6 micrometer, d / Λ = 0.3, n = 7, and inject | emitted via the 1st optical system. It is drawing which shows the spectrum of the light inject | emitted from PCF which made d = 0.6 micrometer, d / Λ = 0.3, n = 10, and inject | emitted via the 1st optical system. It is a graph which shows the relationship between the number of row | line | column n and the wavelength which becomes a cladding mode under d = 0.6 micrometer and d / Λ = 0.3. It is a graph which shows the relationship between the number of row | line | column n and the wavelength which becomes a cladding mode under d = 0.5 micrometer and d / Λ = 0.6. It is drawing which shows the spectrum of the light inject | emitted from PCF which made d = 0.5 micrometer, d / Λ = 0.6, and n = 6, and inject | emitted via the 1st optical system. It is a block diagram which shows typically the structure of the optical analyzer which concerns on this invention. It is a block diagram which shows typically the structure of the optical analyzer which concerns on this invention. It is a block diagram which shows typically another structure of the light source device of this invention. It is a block diagram which shows the conventional optical analyzer typically.

  Embodiments of a light source device and an optical analyzer according to the present invention will be described with reference to the drawings. In the following drawings, the dimensional ratios in the drawings do not necessarily match the actual dimensional ratios.

[Configuration of light source device]
FIG. 1 is a block diagram schematically showing a configuration of a light source device according to the present invention. The light source device 1 includes a laser light source 3 that emits an ultrashort pulsed light 4, a photonic crystal fiber 5 that converts the ultrashort pulsed light 4 into a supercontinuum light 40, and a supercontinuum light 40 that is incident first. And an optical system 7. In the following, the photonic crystal fiber is abbreviated as “PCF” as appropriate, and the supercontinuum light is abbreviated as “SC light” as appropriate.

  The laser light source 3 is a light source that emits laser light (ultrashort pulse light 4) having a pulse width on the order of femtoseconds (fs) to picoseconds (ps). The pulse width of the ultrashort pulse light 4 is preferably 10 ps or less.

  The laser light source 3 preferably has an oscillation wavelength of the emitted ultrashort pulsed light 4 of 500 nm or more and 1100 nm or less. As a specific example, the ultrashort pulse light 4 includes an ultrashort pulse laser oscillator using a titanium: sapphire crystal, an ultrashort pulse laser using a Yb-based crystal such as Yb: KYW, Yb: YAG excited by a semiconductor laser. An oscillator is used.

  FIG. 2 is a schematic cross-sectional view of the PCF 5 cut along a plane perpendicular to the axial direction. The PCF 5 includes a core part 10 and a clad part 20. The clad part 20 includes a first clad part 21 and a second clad part 22. As a base material of PCF5, for example, quartz or a material obtained by adding F or Ge to quartz can be used.

  The core portion 10 corresponds to a position closest to the axis 25 of the PCF 5. The first cladding portion 21 is located outside the core portion 10 and corresponds to a region where a plurality of hole portions 31 are formed as shown in FIG. The plurality of holes 31 are formed so as to penetrate in the axial direction of the PCF 5. The diameter of the hole 31 can be about the wavelength.

  The plurality of holes 31 are arranged in a distributed manner with a predetermined interval. The first clad portion 21 is formed by a plurality of hole portions 31 and a separation portion 32 between adjacent hole portions 31. The first cladding part 21 is configured to cover the outer periphery of the core part 10.

  In the example of FIG. 2, a plurality of holes 31 are arranged in a triangular lattice shape, and the number of columns n = 7 is illustrated. Here, the number n of rows corresponds to the number of the plurality of holes 31 arranged along the radial direction from the axis 25 of the PCF 5.

  The second cladding part 22 is located outside the first cladding part 21. In the present embodiment, unlike the first clad part 21, the second clad part 22 is not formed with a hole 31 and is made of the same material as the core part 10. In addition, the core part 10 and the 2nd clad part 22 do not necessarily need to consist of the same material, and both may be comprised with a different material. As an example, the core part 10 may be formed by adding a predetermined material to the material constituting the second cladding part 22.

  As described above, the PCF 5 converts the ultrashort pulse light 4 emitted from the laser light source 3 into SC light 40 and emits it. In the PCF 5 of this embodiment, among the SC light 40, light 42 in a part of the wavelength band propagates in the core part 10, and light 41 in another wavelength band is transmitted through the cladding part 20 (the first cladding part 21 or the first cladding part 21). It propagates in the two clad portions 22). Here, the wavelength band (hereinafter referred to as “first wavelength band”) of the light 41 propagating in the cladding portion 20 is the wavelength band (hereinafter referred to as “second wavelength band”) of the light 42 propagating in the core portion 10. Longer wavelength than that). This point will be described later with reference to data.

  As described above, the clad portion 20 is disposed outside the core portion 10. For this reason, as schematically shown in FIG. 1, among the SC light 40, the light flux formed by the light 42 in the second wavelength band that has propagated in the core portion 10 is the first wavelength band that has propagated in the cladding portion 20. It is located inside the light beam formed by the light 41. In FIG. 1, the light 41 in the first wavelength band is indicated by a two-dot chain line, and the light 42 in the second wavelength band is indicated by a one-dot chain line.

  The first optical system 7 is configured to emit only the light 42 propagating through the core portion 10 out of the SC light 40 emitted from the PCF 5 to the subsequent stage. 3A and 3B are drawings schematically showing the configuration of the first optical system 7. In any example, the first optical system 7 includes an aperture 51 and a lens 52.

  In the first optical system 7 shown in FIG. 3A, the aperture 51 is arranged in front of the lens 52, and among the SC light 40 emitted from the PCF 5, the light 52 that has propagated in the core portion 10 is the lens 52. On the other hand, the light 41 propagating in the clad portion 20 is not emitted to the lens 52 side by being blocked by the aperture 51. Since the light 41 is emitted through a region outside the light 42, it can be blocked by the aperture 51.

  In the first optical system 7 shown in FIG. 3B, the aperture 51 is arranged behind the lens 52, and the SC light 40 emitted from the PCF 5 is emitted to the aperture 51 through the lens 52. Of the SC light 40 emitted from the lens 52, the light 42 propagating in the core portion 10 is emitted toward the subsequent stage, while the light 41 propagating in the cladding portion 20 is blocked by the aperture 51. Therefore, it does not inject into the latter part.

  3A and 3B, the first optical system 7 may be configured to include optical members other than the aperture 51 and the lens 52 as appropriate.

[Example]
The PCF 5 included in the light source device 1 of the present embodiment can set the mode of propagation of the SC light 40 according to the mode of arrangement of the holes 31 provided in the first cladding portion 21. This point will be described with reference to an embodiment. In the following, the diameter of the hole 31 is denoted by d, and the center-to-center distance between the adjacent holes 31 is denoted by Λ.

(Verification 1)
A plurality of hole portions 31 are arranged in a triangular lattice shape, d = 0.6 μm, d / Λ = 0.3, and the number of columns of hole portions n = 7. The laser light source 3 emitted ultrashort pulsed light 4 having a pulse width of 200 fs, a wavelength of 1040 nm, and an average power of 1000 mW.

  FIG. 4 is a diagram showing the result of electromagnetic field analysis of light (SC light 40) propagating in the PCF 5 when the ultrashort pulsed light 4 is incident on the core part 10 of the PCF 5 under the above conditions. In FIG. 4, the result in the core part 10 vicinity of PCF5 is shown especially. In FIG. 4, a region where a plurality of hole portions are arranged in a triangular lattice shape corresponds to the first cladding portion 21. Further, a region closer to the center than the first clad part 21 and having no hole is formed corresponding to the core part 10. Further, a region outside the first clad portion 21 and having no hole portion corresponds to the second clad portion 22.

  In FIG. 4, the region where the light intensity is high is displayed in black. According to FIG. 4, it can be seen that light having a wavelength of 1570 nm propagates in the core portion 10, but hardly propagates in the cladding portion 20. On the other hand, it can be seen that light having a wavelength of 1580 nm propagates in the clad part 20 (particularly in the second clad part 22) and hardly propagates in the core part 10 at all.

  From this result, among the SC light 40, light having a wavelength of 1570 nm propagates in the core portion 10, but light having a wavelength longer than that of 1580 nm leaks into the cladding portion 20, As can be seen from FIG. The mode propagating in the clad portion 20 is hereinafter referred to as “cladding mode”.

  That is, by arranging the plurality of hole portions 31 in a triangular lattice shape and using the PCF 5 with d = 0.6 μm, d / Λ = 0.3, and n = 7, the SC light 40 generated in the PCF 5 Among them, the light 42 in the wavelength band (second wavelength band) of 1570 nm or less is propagated in the core part 10, and the light 41 in the wavelength band (first wavelength band) of 1580 nm or more is propagated in the cladding part 20. You can see that

  Therefore, by making the SC light 40 emitted from the PCF 5 enter the first optical system 7, only the light 42 having a wavelength band of 1570 nm or less (second wavelength band) is emitted from the first optical system 7. .

  In FIG. 5A, a plurality of hole portions 31 are arranged in a triangular lattice shape, and PCF5 having d = 0.6 μm, d / Λ = 0.3, and n = 7 is used, and the PCF5 through the first optical system 7 is used. It is drawing which shows the spectrum of SC light 40 inject | emitted. According to FIG. 5A, it is confirmed that the intensity of the wavelength component longer than 1570 nm is sharply decreased with 1570 nm as a boundary. That is, it can be seen that the SC light 40 having a wavelength component of 1570 nm or less can be emitted from the first optical system 7 by using the PCF 5.

  FIG. 5B is a diagram showing a spectrum of the SC light 40 emitted from the PCF 5 through the first optical system 7 when the PCF 5 with the number of columns n = 10 is used. Compared with the drawing of FIG. 5A, it is confirmed that a high intensity is also shown for a component having a wavelength of 1580 nm or more.

(Verification 2)
A plurality of hole portions 31 are arranged in a triangular lattice shape, and the number of rows n of the hole portions 31 is changed in a state where d = 0.6 μm and d / Λ = 0.3, and the wavelength at which the cladding mode is obtained is evaluated. did. The conditions of the ultrashort pulsed light 4 emitted from the laser light source 3 are the same as those in the verification 1.

  FIG. 6 is a graph showing the relationship between the number of columns n and the wavelength at which the cladding mode is reached. According to the result of FIG. 6, it can be seen that as the number of columns n increases, the wavelength in the cladding mode shifts to the longer wavelength side.

  That is, according to FIG. 6, for example, when the necessary wavelength band of the SC light 40 is 1470 nm or less, the plurality of hole portions 31 are arranged in a triangular lattice shape, and d = 0.6 μm, d / Λ = 0. 3. By providing the light source device 1 with the PCF 5 in which 3, n = 6, only the light 42 in the wavelength band (second wavelength band) of 1470 nm or less can be extracted from the first optical system 7. As another example, when the required wavelength band of the SC light 40 is 1340 nm or less, the plurality of holes 31 are arranged in a triangular lattice shape, d = 0.6 μm, d / Λ = 0.3, n = By providing the light source device 1 with the PCF 5 set to 5, only the light 42 in the wavelength band (second wavelength band) of 1340 nm or less can be extracted from the first optical system 7.

(Verification 3)
From the laser light source 3, ultrashort pulse light 4 having a pulse width of 200 fs, a wavelength of 1040 nm, and an average power of 1000 mW was emitted to the PCF 5. Then, in a state where a plurality of hole portions 31 are arranged in a triangular lattice shape and d = 0.5 μm and d / Λ = 0.6, the number of columns n of the hole portions 31 is changed, and the wavelength becomes a cladding mode. Evaluated.

  FIG. 7 is a graph showing the relationship between the number of columns n and the wavelength at which the cladding mode is reached under this condition. According to the result of FIG. 7, it can be seen that, as in the case of FIG. 6, as the number of columns n increases, the wavelength in the cladding mode shifts to the long wavelength side.

  That is, according to FIG. 7, for example, when the necessary wavelength band of the SC light 40 is 1160 nm or less, the plurality of holes 31 are arranged in a triangular lattice shape, d = 0.5 μm, d / Λ = 0. Since the light source device 1 includes the PCF 5 with 6 and n = 6, only the light 42 having a wavelength band of 1160 nm or less (second wavelength band) can be extracted from the first optical system 7. As another example, when the required wavelength band of the SC light 40 is 1230 nm or less, a plurality of holes 31 are arranged in a triangular lattice shape, d = 0.5 μm, d / Λ = 0.6, n = By providing the light source device 1 with the PCF 5 set to 7, only the light 42 in the wavelength band of 1230 nm or less (second wavelength band) can be extracted from the first optical system 7.

  FIG. 8 shows a PCF 5 in which a plurality of holes 31 are arranged in a triangular lattice shape and d = 0.5 μm, d / Λ = 0.6, and n = 6, and the PCF 5 through the first optical system 7. It is drawing which shows the spectrum of SC light 40 inject | emitted. According to FIG. 8, it is confirmed that the intensity of the wavelength component longer than 1160 nm sharply decreases with 1160 nm as a boundary. That is, it can be seen that the SC light 40 having a wavelength component of 1160 nm or less can be emitted from the first optical system 7 by using the PCF 5.

[Configuration of optical analyzer]
FIG. 9A is a block diagram schematically showing the configuration of the optical analyzer according to the present invention. The optical analyzer 60 includes the light source device 1 described above, a sample stage 61, and a spectrometer 62. A sample 63 to be analyzed is placed on the sample stage 61. The optical analysis device 60 may include another lens 65 and a filter 69 as necessary.

  The SC light 40 emitted from the first optical system 7 included in the light source device 1, more specifically the light 42 in the second wavelength band, is incident on the sample 63. Then, anti-Stokes light (CARS light) 67 is emitted from the sample 63. When the light source device 1 includes the filter 69, the long wavelength light is blocked by the filter 69, and substantially only the CARS light 67 is incident on the spectroscope 62. The spectroscope 62 can analyze the sample 63 by using a known technique such as spectrum analysis. The filter 69 can be composed of a band pass filter, a short pass filter, or the like. Examples of the long wavelength light blocked by the filter 69 include the second wavelength band light 42 used for exciting the sample 63.

  When the sample 63 includes a phosphor capable of multiphoton excitation in advance, fluorescence 68 by multiphoton excitation is emitted from the sample 63 as shown in FIG. 9B. Also in this case, the fluorescence 68 is incident on the spectroscope 62 in the same manner as described above, and the sample 63 can be analyzed by using a known technique such as spectrum analysis in the spectroscope 62. In the case where the light source device 1 includes the filter 69, the long wavelength light is blocked by the filter 69, and only the fluorescence 68 is substantially incident on the spectroscope 62.

  As described above, the SC light 40 emitted from the light source device 1 does not include the light 41 in the first wavelength band. The light 41 in the first wavelength band is unnecessary for the analysis of the sample 63, but rather corresponds to a component in the long wavelength band that heats the sample 63. For this reason, according to the optical analyzer 60, even when the sample 63 is a biological sample, it is possible to analyze with high accuracy even a sample that may be deformed by being heated. In addition, since it is not necessary to separately provide a filter for cutting long wavelength components, the number of parts is reduced and the optical design is simplified.

[Another embodiment]
Hereinafter, another embodiment will be described.

  <1> The configuration of the first optical system 7 shown in FIGS. 3A and 3B is merely an example. The first optical system 7 has another configuration as long as the first optical system 7 emits only the light 42 in the second wavelength band propagating through the core 10 out of the SC light 40 emitted from the PCF 5. It doesn't matter.

  As an example, the first optical system 7 is provided at the emission side end portion of the PCF 5 and has a translucent body having an inclined portion whose inner diameter is shortened along the optical path direction, and light emitted from the translucent body in a subsequent stage. It is also possible to provide a lens 52 that leads to According to this configuration, the light 41 in the first wavelength band propagated through the clad portion 20 is transmitted and emitted to the outside of the PCF 5 through the inclined portion of the translucent body.

  Further, as another example, the first part propagated through the cladding part 20 by providing a taper part on a part of the outer periphery of the PCF 5 or immersing the PCF 5 in a liquid having a refractive index equivalent to the material of the PCF 5 (for example, glycerin). A configuration may be adopted in which light 41 in the wavelength band is emitted to the outside. In this case, the first optical system 7 can be configured to include only the lens 52 guided to the subsequent stage.

  That is, the PCF 5 has a configuration in which the light 41 in the first wavelength band propagates to some extent through the cladding portion 20, but little or no light 41 in the first wavelength band is emitted at the end on the first optical system 7 side. I do not care. In this case, as shown in FIG. 10, only the light 42 in the second wavelength band emitted from the core unit 10 may be incident on the first optical system 7. Also in this case, the light 41 in the first wavelength band may be propagated through the cladding portion 20 of the PCF 5 from the incident side end face of the ultrashort pulsed light 4 over a predetermined fiber length.

  <2> The configuration of the optical system described above is merely an example, and an optical system such as a collimator lens and a reflection mirror may be separately provided as necessary.

  <3> In the embodiment described above, the plurality of hole portions 31 are arranged in a triangular lattice shape, and the diameter d of the hole portions 31 and the center-to-center distance Λ between adjacent hole portions 31 are described as being constant values. did. However, the values of d and Λ may have different values within a manufacturing error range (for example, ± 10%).

1: Light source device 3: Laser light source 4: Ultrashort pulse light 5: Photonic crystal fiber (PCF)
7: 1st optical system 10: Core part 20: Clad part 21: 1st clad part 22: 2nd clad part 25: Axis of PCF 31: Hole 32: Separation part 40: Super continuum light (SC light)
41: Supercontinuum light in the first wavelength band 42: Supercontinuum light in the second wavelength band 51: Aperture 52: Lens 60: Optical analyzer 61: Sample stage 62: Spectrometer 63: Sample 65: Lens 67: Anti Stokes light (CARS light)
68: Fluorescence 69: Filter 100: Conventional optical analyzer 101: Ultrashort pulse laser light source 102: Condensing lens 103: Photonic crystal fiber 104: Collimate lens 105: Long pass filter 106: Objective lens 107: Sample 108: Condenser lens 109: Short pass filter 110: Spectrometer 111: Spectrometer 112: Detector

Claims (5)

A laser light source that emits ultra-short pulse light;
A photonic crystal fiber that converts the incident ultrashort pulse light into supercontinuum light and emits the light; and
A first optical system on which the supercontinuum light is incident,
The photonic crystal fiber is
A core corresponding to the position closest to the axis of the photonic crystal fiber;
There are a plurality of holes that are located outside the core part and penetrate in the axial direction of the photonic crystal fiber, and the plurality of holes are dispersed so as to cover the core part with a predetermined interval. A first clad portion arranged by
A second clad portion which is located outside the first clad portion, is not formed with the hole portion and is made of the same material as the core portion,
In the first optical system, the light in the first wavelength band propagated through the second cladding portion out of the supercontinuum light is not emitted to the subsequent stage, but is propagated through the core portion. A light source device that emits light in a second wavelength band shorter than the first wavelength band in a subsequent stage.   The light source device according to claim 1, wherein the first optical system includes an aperture that allows only light that has passed through the core portion to pass.   The light source device according to claim 1, wherein the first optical system includes a lens that collects only light that has passed through the core portion. The first cladding part is
The plurality of holes are formed by arranging in a triangular lattice shape,
4. The light source device according to claim 1, wherein the number of columns n of the triangular lattice is set so that the first wavelength band has a wavelength of at least 1600 nm or more. The light source device according to any one of claims 1 to 4,
A sample stage on which a sample to be measured is placed;
With a spectroscope,
When the sample is irradiated with light in the first wavelength band emitted from the first optical system, anti-Stokes light emitted from the sample or fluorescence emitted from the sample by multiphoton excitation is reflected in the spectrum. An optical analyzer characterized by being incident on a vessel.

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