JP6090954B2 - Laser oscillation element made of colloidal crystal gel and method for manufacturing the same - Google Patents

Description

  The present invention relates to a laser oscillation element made of a colloidal crystal gel and a manufacturing method thereof.

  In a fine particle dispersion in which fine particles are dispersed in a liquid medium, if the fine monodispersity (uniformity of particle size) is high and the particle volume fraction exceeds a predetermined value, the fine particles in the fine particle dispersion (colloid) (Also called particles) are known to take a self-organized periodic arrangement. The fine particle dispersion in such a state is called a colloidal crystal. Colloidal crystals exhibit unique properties (photonic band gap formation, anomalous dispersion of light group velocity, etc.) due to Bragg reflectivity for electromagnetic waves, so application to optical elements utilizing the properties of photonic crystals Is expected.

There is a laser using a colloidal crystal infiltrated with a dye (for example, see Non-Patent Document 1). According to Non-Patent Document 1, it is reported that in an opal photonic crystal composed of silica particles infiltrated with a dye, the photonic band gap can be made variable by switching the three-dimensional direction. More specifically, by appropriately selecting the stop band orientation ν _hkl of the opal photonic crystal made of silica particles infiltrated with the dye, a laser corresponding to various dyes can be used even with one kind of opal photonic crystal. Oscillation is possible. However, fine tuning of the oscillation wavelength or linear tunability has not been achieved without selecting the stopband orientation.

  There is a colloidal crystal laser using porous silica in which a dye is introduced into pores (see, for example, Non-Patent Document 2). According to Non-Patent Document 2, laser oscillation is possible in a colloidal crystal laser made of porous silica in which a dye is introduced into pores by matching the fluorescence wavelength of the dye with the stopband wavelength of the colloidal crystal gel. It is reported that. However, since water is used as the solvent for the colloidal crystal gel, long-term stability of laser oscillation cannot be obtained due to a change in the stopband wavelength accompanying water evaporation. Further, since the dye is introduced into the pores of the porous silica, there are cases where sufficient emission intensity cannot be obtained. Furthermore, the tunability of the oscillation wavelength has not been achieved.

  Recently, colloidal crystal gels containing ionic liquids have been developed (see, for example, Patent Document 1). According to Patent Document 1, by using an ionic liquid as a solvent, the solvent of the colloidal crystal gel does not evaporate, so that a long-term stable colloidal crystal gel can be provided. There is a need for further applications of colloidal crystal gels using such ionic liquids.

  An object of the present invention is to provide a tunable laser oscillation device using a colloidal crystal gel and a method for manufacturing the same.

A laser oscillation element comprising a colloidal crystal gel according to the present invention, the colloidal crystal gel is a polymer gel containing an ionic liquid and an organic dye, and particles self-organized in the polymer gel, The particle array includes particles in a non-contact packed state, the ionic liquid is hydrophilic and has an allyl group at a terminal, and the stop band of the colloidal crystal gel is at least the organic It is located in a wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the dye, and is located within the range of the fluorescence spectrum, thereby achieving the above-described object .
Before SL ionic liquid, 1-allyl-3-butyl imidazolium halides, 1-allyl-3-ethyl imidazolium halides, and, be selected from the group consisting of 1,3-diallyl-butyl imidazolium halides Good.
The organic dye is at least one selected from the group consisting of rhodamine derivatives, oxazine derivatives, fluorescein derivatives, coumarin derivatives, styryl derivatives and 4-dicyanomethylene-2-methyl-6 (p-dimethylaminostyryl) -4H-pyran (DCM). Species may be selected.
The method for producing a laser oscillation device according to the present invention includes a step of impregnating a colloidal crystal gel in which self-organized and periodically arranged particles are fixed by a network polymer with an ionic liquid and an organic dye, In the organic dye, the stop band of the colloidal crystal gel obtained by the impregnation step is located at least in a wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye, and is located within the range of the fluorescence spectrum. To achieve the above task.
The impregnation step may include impregnating the colloidal crystal gel swollen with water with an ionic liquid and further impregnating the colloidal crystal gel swollen with the ionic liquid with an ionic liquid and an organic dye. .
In the impregnation step, the colloidal crystal gel may be impregnated with an ionic liquid and an organic dye for 1 hour to 14 days.

  The laser oscillation element made of a colloidal crystal gel according to the present invention includes a polymer gel and particles containing an ionic liquid and an organic dye. Since the organic dye is dispersed in the colloidal crystal gel, sufficient emission intensity can be obtained. Since the particles in the colloidal crystal gel are in a non-contact state, the stop band of the colloidal crystal gel is variable by an external force. In addition, since the stop band of the colloidal crystal gel is located at least in the wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye, and is located within the range of the fluorescence spectrum, just controlling the stop band by external force, Laser oscillation with a narrow linewidth can be tuned in a wavelength region longer than the maximum fluorescence wavelength of the organic dye and in the fluorescence spectrum.

  A laser oscillation device according to the present invention includes a light source, the laser oscillation element, and a stress application unit. The stress application unit applies stress to the laser oscillation element and linearizes a stop band of the colloidal crystal gel in the laser oscillation element. Therefore, tunable laser oscillation can be easily performed.

  The method for manufacturing a laser oscillation device according to the present invention includes a step of impregnating a colloidal crystal gel in which self-organized and periodically arranged particles are fixed by a network polymer with an ionic liquid and an organic dye. The dye is selected so that the stop band of the colloidal crystal gel obtained by the impregnation step is at least in the wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye and in the fluorescence spectrum. Since the laser oscillation device of the present invention can be produced by a one-step operation only by appropriately selecting the stop band of the colloidal crystal gel and the fluorescence spectrum of the organic dye, it is simple and advantageous.

Schematic diagram of a laser oscillation device according to the present invention The schematic diagram which shows the mode of the laser oscillation of the laser oscillation element by this invention The schematic diagram which shows the change at the time of applying external force to the laser oscillation element by this invention Schematic diagram showing the tunability of the oscillation wavelength when an external force is applied to the laser oscillation element according to the present invention. Schematic diagram of another laser oscillation element according to the present invention The schematic diagram which shows the mode of the laser oscillation of another laser oscillation element by this invention The schematic diagram which shows the change at the time of applying external force to another laser oscillation element by this invention Schematic diagram showing the tunability of oscillation wavelength when an external force is applied to another laser oscillation element according to the present invention. The figure which shows the flowchart which manufactures the laser oscillation element which consists of colloidal crystal gel by this invention The figure which shows another flowchart which manufactures the laser oscillation element which consists of colloidal crystal gel by this invention Schematic diagram showing a laser oscillation device according to the present invention. Schematic diagram showing an optical microscope system Schematic diagram showing stress application means The figure which shows the external force dependence of the stop band of the laser oscillation element by Example 1 The figure which shows the relationship between the stop band and compression rate of the laser oscillation element of Example 1. The figure which shows the absorption spectrum of the ionic liquid ABImBr used in Example 1 The figure which shows the reflection spectrum and emission spectrum of the laser oscillation element of Example 1 in compression rate _Rcom = 0.1. The figure which shows the three-dimensional beam profile of the laser oscillation element of Example 1 in compression rate _Rcom = 0.1. The figure which shows the one-dimensional beam profile of the laser oscillation element of Example 1 in compression rate _Rcom = 0.1. The figure which shows the dependence of the emitted light intensity of the laser oscillation element of Example 1 and the line width on the excitation energy in compression rate _Rcom = 0.1 The figure which shows the tunability of the emission spectrum of the laser oscillation element of Example 1. The figure which shows the tunability of the emission spectrum of the laser oscillation element of Example 2 The figure which shows the microscope image of the laser oscillation of the laser oscillation element of Example 2 The figure which shows the change of the conventional type colloidal crystal gel of the comparative example 1 The figure which shows the absorption spectrum of the mixed solution of the comparative example 2 The figure which shows the emission spectrum of the mixed solution of Example 3 and Comparative Example 2 The figure which shows the absorption spectrum of the mixed solution of the comparative example 3 The figure which shows the emission spectrum of the mixed solution of Example 3 and Comparative Example 3

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same number is attached | subjected to the same element and the description is abbreviate | omitted.

(Embodiment 1)
The first embodiment relates to a laser oscillation element according to the present invention.

  FIG. 1 is a schematic diagram of a laser oscillation element according to the present invention.

  The laser oscillation device 100 according to the present invention is made of a colloidal crystal gel including particles (also referred to as fine particles) 110, a network polymer 120, an ionic liquid 130, and an organic dye 140. In the present specification, the reticulated polymer 120 is in a state containing the ionic liquid 130 and the organic dye 140, and is collectively referred to as “polymer gel”. As a matter of course, in the polymer gel, the particle 110 is self-organized in a periodic arrangement constituting a crystal structure, and exhibits Bragg reflection of light based on the principle of crystallography. Furthermore, the particles 110 are in a non-contact packed state without contacting each other.

  The particles 110 are also called colloidal particles, and are, for example, silica particles, polystyrene particles, polymer latex particles, oxide particles such as titanium dioxide, metal particles, and composite particles combining different materials, but are not limited thereto. The composite particles are configured by combining two or more different materials (materials). For example, one material is encapsulated with the other material to form one particle, Means that one material penetrates into the other material to form one particle, or different hemispherical materials combine to form one particle.

  Whether or not the colloidal crystal gel particles 110 are in a non-contact packed state can be determined from the particle volume fraction. It is known that the particle volume fraction is theoretically 74% when the hard spherical particles having the same particle diameter come into contact with each other to form a close packed structure. As an actual determination criterion, it is realistic that “substantially contact” is achieved up to a place where the distance between particles is about 10% larger than the theoretical close packed state. In this case, the particle volume fraction is about 55%. Therefore, in this specification, the case where the particle volume fraction is less than 55% is determined as the non-contact filling state. The particle volume fraction of the colloidal crystal gel impregnated with the ionic liquid can be easily determined from the volume change from the starting colloidal crystal gel before the ionic liquid impregnation. The particle volume fraction of the starting colloidal crystal gel can be determined from the preparation conditions.

In FIG. 1, it is assumed that the particle 110 has a lattice spacing d _A in a state where no external force is applied, the particle volume fraction is the minimum value, and the stop band is the wavelength λ _A. By appropriately adjusting the particle volume fraction, the stop band of the colloidal crystal gel can be controlled. For example, the smaller the particle volume fraction, the longer the stop band, and the larger the particle volume fraction, the shorter the stop band.

In the laser oscillation device 100 according to the present invention, as will be described in detail later, the stop band of the colloidal crystal gel has a longer wavelength region than the maximum fluorescence wavelength λ _max of the fluorescence spectrum 150 of the organic dye 140 described later, and the fluorescence spectrum 150. It is variable within the range.

  The network polymer 120 is a network polymer in which a polymer formed by polymerization of a polymerizable water-soluble molecule (monomer or macromer) forms a three-dimensional network structure by crosslinking. The network polymer 120 functions to fix and maintain the position of the particles 110 described above. Examples of such water-soluble molecules include acrylamide, various acrylamide derivatives (N-methylolmethacrylamide, N-methylolacrylamide, N-acryloisoaminoethoxyethanol, N-acryloisoaminopropanol, N-isopropylacrylamide, etc.). Alternatively, acrylic acid derivatives and ethylene glycol derivatives can be used, but are not limited thereto. In this specification, unless otherwise specified, it is noted that the “network polymer” is intended to mean a network polymer formed by a polymer of a polymerizable water-soluble molecule. I want.

  The ionic liquid 130 functions as a dispersion medium (also simply referred to as a solvent). The ionic liquid 130 does not evaporate because the vapor pressure is substantially zero. Therefore, when the laser oscillation element 100 of the present invention is stored or mounted as an optical element, it is not necessary to seal the laser oscillation element 100 in a sealed structure such as a sealed container in order to prevent the dispersion medium from evaporating. .

  The ionic liquid 130 is preferably hydrophilic and has an allyl group at the terminal. Thereby, since it mixes well with the organic pigment | dye 140 mentioned later, stable laser oscillation is enabled. The ionic liquid 130 is more preferably selected from the group consisting of 1-allyl-3-butylimidazolium halide, 1-allyl-3-ethylimidazolium halide, and 1,3-diallylbutylimidazolium halide. Is done. Thereby, since it mixes with the organic pigment | dye 140 mentioned later reliably, stable laser oscillation and high oscillation intensity | strength are enabled. In addition, since the ionic liquid 130 and the organic dye 140 do not react, a long-term stable laser oscillation element can be provided. In FIG. 1, for the sake of simplicity, the organic dye 140 is composed of one kind of organic dye.

  For example, 1-allyl-3-butylimidazolium halide is advantageous in the production of the laser oscillation device of the present invention described in Embodiment 3 because it has an excellent affinity for water. In addition, 1-allyl-3-butylimidazolium halide is optically extremely transparent because it does not have an intrinsic molar absorption coefficient in a wavelength region of 280 nm or more. Furthermore, 1-allyl-3-butylimidazolium halide can easily dissolve the organic dye 140 described below, among which rhodamine derivatives. Also, 1-allyl-3-butylimidazolium halide is known as an environmentally friendly material, and is a low risk chemical substance in a hazardous substance identification system (HMIS).

  The organic dye 140 is at least one selected from the group consisting of rhodamine derivatives, oxazine derivatives, fluorescein derivatives, coumarin derivatives, styryl derivatives and -dicyanomethylene-2-methyl-6 (p-dimethylaminostyryl) -4H-pyran (DCM). Selected. These are miscible with the ionic liquid 130 described above.

  For example, rhodamine 6G as a rhodamine derivative has an emission wavelength of 550 nm to 620 nm and emits green, yellow to orange. As an oxazine derivative, phenoxazine has an emission wavelength of 560 to 700 nm and emits green, yellow, orange to red. As another oxazine derivative, oxazine 1 has a light emission wavelength of 692 nm to 768 nm and emits red light. Disodium fluorescein as a fluorescein derivative has an emission wavelength of 530 nm to 590 nm, and emits yellowish green and green to yellow. As another fluorescein derivative, fluorescein 27 has an emission wavelength of 540 nm to 589 nm and emits yellowish green and green to yellow. As a coumarin derivative, coumarin 4 has an emission wavelength of 460 nm to 560 nm and emits blue to green. As another coumarin derivative, coumarin 153 has an emission wavelength of 522 nm to 600 nm and emits blue-green and green to yellow. As a styryl derivative, stilbene 1 has an emission wavelength of 405 nm to 446 nm and emits blue. DCM has an emission wavelength of 590 nm to 710 nm and emits red light.

As described above, the maximum fluorescence wavelength of the fluorescence spectrum 150 of the organic dye 140 is shorter than the stop band of the colloidal crystal gel and the stopband of the colloidal crystal is variable within the range of the fluorescence spectrum. The organic dye 140 is selected. More specifically, as shown in FIG. 1, the maximum fluorescence wavelength of the fluorescence spectrum 150 (FIG. 1) of the organic dye 140 is λ _max , and the stop band of the reflection spectrum 160 (FIG. 1) of the colloidal crystal gel is λ _A Λ _A > λ _max and λ _A is located within the fluorescence spectrum 150.

For example, when the stop band λ _A of the colloidal crystal gel is 700 nm, phenoxazine, oxazine 1 or the like can be used as the organic dye 140, but stilbene 1 cannot be used. When the stop band λ _A of the colloidal crystal gel is 500 nm, coumarin 4, stilbene 1 and the like can be used as the organic dye 140, but phenoxazine and oxazine 1 cannot be used.

  Next, the principle of laser oscillation of the laser oscillation device 100 according to the present invention shown in FIG. 1 will be described.

  FIG. 2 is a schematic view showing a state of laser oscillation of the laser oscillation element according to the present invention.

The laser oscillation element shown in FIG. 2 is the same as the laser oscillation element 100 of FIG. 1 and is in a state where no external force is applied. When excitation light (wavelength λ _ex ) enters the laser oscillation element 100 in the film thickness direction, the laser oscillation element 100 converts the excitation light (wavelength λ _ex ) into converted light 200 (wavelength λ _emA ) and outputs it.

More specifically, the organic dye 140 of the laser oscillation element 100 can absorb excitation light and emit fluorescence having the maximum fluorescence wavelength λ _max shown in the fluorescence spectrum 150. The wavelength λ _ex may be a wavelength sufficiently shorter than the wavelength of the fluorescence spectrum 150 of the organic dye 140. However, the laser oscillation element 100 actually has a longer wavelength than the stop band λ _A of the reflection spectrum 160 of the laser oscillation element 100 without emitting the fluorescence spectrum 150, and the reflection spectrum 160 and the fluorescence spectrum of the organic dye 140 A converted light 200 having a wavelength λ _emA in the range of 150 can be emitted. This is due to resonance enhancement of the density of states (DOS) in the emitted photons near the reflection band edge. That is, it means that the reflection band (reflection spectrum 160) of the laser oscillation element 100 functions well as a photonic band gap (PBG). Further, the laser line width of the converted light 200 is extremely narrow, and is in the range of 0.01 nm to 5 nm.

  Next, the change in the stop band when an external force is applied to the laser oscillation element 100 according to the present invention shown in FIG. 1 will be described.

  FIG. 3 is a schematic diagram showing a change when an external force is applied to the laser oscillation element according to the present invention.

The laser oscillation element 100 shown in FIG. 3A is the same as the laser oscillation element 100 in FIG. 1 and is in a state where no external force is applied. When an external force (compressive stress) is applied to the laser oscillation element 100 in the film thickness direction, the laser oscillation element 100 changes to a laser oscillation element 310 as shown in FIG. At this time, the lattice spacing changes from d _A to d _B (d _B <d _A ), and the stop band also changes from the wavelength λ _A to the wavelength λ _B (λ _B <λ _A ). Further, when an external force is applied to the laser oscillation element 310 in the film thickness direction, the laser oscillation element 310 changes to a laser oscillation element 320 as shown in FIG. At this time, the lattice spacing changes from d _B to d _C (d _C <d _B ), and the stop band also changes from the wavelength λ _B to the wavelength λ _C (λ _C <λ _B ). When an external force is further applied to the laser oscillation element 320 in the film thickness direction, the laser oscillation element 320 changes to a laser oscillation element 330 as shown in FIG. At this time, the lattice spacing changes from d _C to d _D (d _D <d _C ), and the stop band also changes from the wavelength λ _C to the wavelength λ _D (λ _D <λ _C ). Here, the colloidal crystal gel constituting the laser oscillation element 330 is in a contact filling state, and even when an external force is applied beyond this, the lattice spacing is not shortened, and the stop band is not shifted to the short wavelength side.

  As described with reference to FIG. 3, since the colloidal crystal gel constituting the laser oscillation device 100 of the present invention is in a non-contact filling state, the stop band is blue shifted toward the short wavelength side as an external force is applied. To do. The blue shift accompanying the application of external force continues until the colloidal crystal gel is in a contact filling state, and does not shift thereafter. FIG. 3 shows a specific non-contact filling state (FIGS. 3A to 3C, etc.), but depending on the degree of application of external force, FIGS. 3A to 3B and FIG. Note that any contact packed colloidal crystal gel between ~ (C) or Figures 3 (C)-(D) can be achieved.

  Next, the tunability of the oscillation wavelength of the laser oscillation device 100 of the present invention will be described.

  FIG. 4 is a schematic diagram showing the tunability of the oscillation wavelength when an external force is applied to the laser oscillation element according to the present invention.

  In FIG. 4, the laser oscillation elements 100, 310, 320, and 330 and their stop bands are all the same as the laser oscillation element and the stop band described in FIG. Moreover, the fluorescence spectrum 150 of FIG. 4 is the same as the fluorescence spectrum 150 of FIG. 1 and FIG.

As described with reference to FIG. 2, when excitation light (wavelength λ _ex ) is incident on the laser oscillation element 100 of FIG. 4 in the film thickness direction, the organic dye 140 of the laser oscillation element 100 absorbs the excitation light, Although it is possible to emit fluorescence having the maximum fluorescence wavelength λ _max shown in the fluorescence spectrum 150, the laser oscillation element 100 actually has a longer wavelength than the stop band λ _A of the laser oscillation element 100 without emitting the fluorescence spectrum 150. In addition, it is possible to emit converted light having a wavelength λ _emA within the range of the reflection spectrum of the laser oscillation element 100 and the fluorescence spectrum 150 of the organic dye 140.

Similarly, when excitation light (wavelength λ _ex ) enters the laser oscillation element 310 of FIG. 4, the organic dye 140 of the laser oscillation element 310 absorbs the excitation light and has fluorescence having a maximum fluorescence wavelength λ _max shown in the fluorescence spectrum 150. In practice, the laser oscillation element 310 has a longer wavelength than the stop band λ _B of the laser oscillation element 310 and does not emit the fluorescence spectrum 150, and is longer than the stop band λ _A of the laser oscillation element 100. Converted light (λ _max <λ _emB <λ _emA ) having a wavelength λ _emB that has a short wavelength and falls within the range of the reflection spectrum of the laser oscillation element 310 and the fluorescence spectrum 150 of the organic dye 140 can be emitted.

Similarly, when excitation light (wavelength λ _ex ) is incident on the laser oscillation element 320 of FIG. 4, the organic dye 140 of the laser oscillation element 320 absorbs the excitation light and has fluorescence having a maximum fluorescence wavelength λ _max shown in the fluorescence spectrum 150. In practice, the laser oscillation element 320 has a longer wavelength than the stop band λ _C of the laser oscillation element 320 and does not emit the fluorescence spectrum 150, and is longer than the stop band λ _B of the laser oscillation element 310. Converted light (λ _max <λ _emC <λ _emB ) having a wavelength λ _emC that has a short wavelength and falls within the range of the reflection spectrum of the laser oscillation element 320 and the fluorescence spectrum 150 of the organic dye 140 can be emitted.

Similarly, when excitation light (wavelength λ _ex ) enters the laser oscillation element 330 of FIG. 4, the organic dye 140 of the laser oscillation element 330 absorbs the excitation light and has fluorescence having a maximum fluorescence wavelength λ _max shown in the fluorescence spectrum 150. In practice, the laser oscillation element 330 does not oscillate at all. This is because in FIG. 4, the stop band λ _D of the laser oscillation element 330 is in a shorter wavelength region than the maximum fluorescence wavelength λ _max of the fluorescence spectrum 150. In FIG. 4, if the stop band of the laser oscillation element 330 is in the wavelength region longer than the maximum fluorescence wavelength λ _{max of} the fluorescence spectrum 150 and is within the fluorescence spectrum 150, the same as the laser oscillation elements 100, 310, and 320. It should be understood that lasing can occur.

  As described with reference to FIGS. 3 and 4, if the stop band and the organic dye are appropriately selected, the oscillation wavelength tuner of the laser oscillation element made of the colloid crystal gel is controlled by controlling the stop band of the colloid crystal gel. Is achieved.

(Embodiment 2)
The second embodiment relates to another laser oscillation element according to the present invention. In the first embodiment, an example in which the organic dye 140 is a kind is shown, but in the second embodiment, an example in which the organic dye 140 is two or more kinds is shown.

  FIG. 5 is a schematic view of another laser oscillation element according to the present invention.

  The laser oscillation element 500 according to the present invention is made of a colloidal crystal gel including particles (also referred to as fine particles) 110, a network polymer 120, an ionic liquid 130, and an organic dye 510. The particles 110, the network polymer 120, and the ionic liquid 130 are as described above with reference to FIG. Further, the particles 110 of the laser oscillation element 500 are in a non-contact filling state, and no external force is applied.

  The organic dye 510 is selected from the group consisting of a rhodamine derivative, an oxazine derivative, a fluorescein derivative, a coumarin derivative, and a styryl derivative, as in the organic dye 140 of the first embodiment. Two types are assumed to be mixed. Similar to the organic dye 140 of the first embodiment, the organic dye 510 can also be mixed with the ionic liquid 130.

In addition, the combination of the organic pigment | dye 510 from which the maximum fluorescence wavelength of the fluorescence spectrum of each organic pigment | dye differs is preferable. Thereby, the tunability of the oscillation wavelength of the laser oscillation element 500 can be expanded. For example, the organic dye 510 is a combination of an organic dye having a fluorescence spectrum 150 (similar to the organic dye 140 of Embodiment 1) and an organic dye having a fluorescence spectrum 530. The fluorescence spectrum 150 has a maximum fluorescence wavelength λ _max , and the fluorescence spectrum 530 has a maximum fluorescence wavelength λ _{max ′} (satisfying λ _{max ′} <λ _max ). It should be noted that the actual fluorescence spectrum of the organic dye 510 becomes one fluorescence spectrum (not shown) that combines the fluorescence spectrum 150 and the fluorescence spectrum 530, and the shape thereof may change depending on the mixing ratio of the organic dye. I want.

As in Embodiment 1, in the laser oscillation device 500 according to the present invention, the stop band 160 of the colloidal crystal gel has a longer wavelength region than the maximum fluorescence wavelengths λ _max and λ _{max ′} of the fluorescence spectra 150 and 530 of the organic dye 510, And what is necessary is just to be variable within the range of at least any one of the fluorescence spectra 150 and 530.

  Next, the principle of laser oscillation of the laser oscillation device 500 according to the present invention will be described.

  FIG. 6 is a schematic diagram showing a state of laser oscillation of another laser oscillation element according to the present invention.

When excitation light (wavelength λ _{ex ′} ) is incident in the film thickness direction of the laser oscillation element 500, the laser oscillation element 500 converts the excitation light (wavelength λ _{ex ′} ) into converted light 600 (wavelength λ _{emA ′} ) for output. To do.

More specifically, the organic dye 510 of the laser oscillation device 500 can absorb the excitation light and emit fluorescence having the maximum fluorescence wavelengths λ _max and λ _{max ′} shown in the fluorescence spectra 150 and 530. The wavelength λ _{ex ′} can be a wavelength sufficiently shorter than the wavelengths of the fluorescence spectra 150 and 530 of the organic dye 510. However, actually, the laser oscillation element 500 does not emit the fluorescence spectra 150 and 530, has a wavelength longer than the stop band λ _A of the reflection spectrum 160 of the laser oscillation element 500, and reflects the reflection spectrum 160 and the organic dye. A converted light 600 having a wavelength λ _{emA ′} at least within the range of the fluorescence spectrum 150 of 510 can be emitted. Further, the laser line width of the converted light 600 is extremely narrow, and is in the range of 0.01 nm to 5 nm. Here, the stop band λ _A and the wavelength λ _{emA ′} of the converted light 600 may be the same as the stop band λ _A and the wavelength λ _emA of the converted light 200 described with reference to FIG. Some combinations may vary.

  Next, changes in the stop band when an external force is applied to another laser oscillation element 500 of the present invention will be described.

  FIG. 7 is a schematic diagram showing a change when an external force is applied to another laser oscillation element according to the present invention.

The laser oscillation element 500 shown in FIG. 7A is the same as the laser oscillation element 500 in FIG. 5 and is in a state where no external force is applied. When an external force (compressive stress) is applied to the laser oscillation element 500 in the film thickness direction, the laser oscillation element 500 changes to a laser oscillation element 710 as shown in FIG. At this time, the lattice spacing changes from d _A to d _B (d _B <d _A ), and the stop band also changes from the wavelength λ _A to the wavelength λ _B (λ _B <λ _A ). Further, when an external force is applied to the laser oscillation element 710 in the film thickness direction, the laser oscillation element 710 changes to a laser oscillation element 720 as shown in FIG. At this time, the lattice spacing changes from d _B to d _C (d _C <d _B ), and the stop band also changes from the wavelength λ _B to the wavelength λ _C (λ _C <λ _B ). When an external force is further applied to the laser oscillation element 720 in the film thickness direction, the laser oscillation element 720 changes to a laser oscillation element 730 as shown in FIG. At this time, the lattice spacing changes from d _C to d _D (d _D <d _C ), and the stop band also changes from the wavelength λ _C to the wavelength λ _D (λ _D <λ _C ). Here, the colloidal crystal gel constituting the laser oscillation element 730 is in a contact filling state, and even when an external force is applied beyond this, the lattice spacing is not shortened, and the stop band is not shifted to the short wavelength side.

  Here, for the sake of simplicity, the changes in the lattice spacing and the stop band when an external force is applied to the laser oscillation element 500 are the same as those of the laser oscillation element 100 described with reference to FIG. However, it is not limited to this.

  Next, the tunability of the oscillation wavelength of the laser oscillation element 500 of the present invention will be described.

  FIG. 8 is a schematic diagram showing the tunability of the oscillation wavelength when an external force is applied to another laser oscillation element according to the present invention.

  In FIG. 8, the laser oscillation elements 500, 710, 720, and 730 and their stop bands are all the same as the laser oscillation element and the stop band described with reference to FIG. Further, the fluorescence spectra 150 and 530 in FIG. 8 are the same as the fluorescence spectra 150 and 530 in FIGS.

As described with reference to FIG. 6, when excitation light (wavelength λ _{ex ′} ) enters the laser oscillation element 500 in FIG. 5 in the film thickness direction, the organic dye 510 of the laser oscillation element 500 absorbs the excitation light. In this case, the laser oscillation element 500 can emit fluorescence having the maximum fluorescence wavelengths λ _max and λ _{max ′} shown in the fluorescence spectra 150 and 530, but actually, the laser oscillation element 500 does not emit the fluorescence spectra 150 and 530. It is possible to emit converted light 600 having a wavelength λ _{emA ′} that is longer than the stop band λ _{A and} has a reflection spectrum of the laser oscillation element 500 and at least a fluorescence spectrum 150 of the organic dye 530.

Similarly, when excitation light (wavelength λ _{ex ′} ) enters the laser oscillation element 710 of FIG. 8, the organic dye 510 of the laser oscillation element 710 absorbs the excitation light, and the maximum fluorescence wavelength λ _max shown in the fluorescence spectra 150 and 530 is obtained. and lambda _{max 'may} fluoresce with, but in practice, laser oscillation device 710, without emitting fluorescence spectra 150 and 530, a wavelength longer than the stop band lambda _B of the laser oscillation device 710, the laser oscillation Converted light (λ) having a wavelength λ _{emB ′} having a wavelength shorter than the stop band λ _A of the element 500 and within the range of the reflection spectrum of the laser oscillation element 710 and the fluorescence spectrum 150 and / or 530 of the organic dye 510 _{max ′} <λ _max <λ _{emB ′} <λ _{emA ′} ).

Similarly, when excitation light (wavelength λ _{ex ′} ) enters the laser oscillation element 720 of FIG. 8, the organic dye 510 of the laser oscillation element 720 absorbs the excitation light, and the maximum fluorescence wavelength λ _max shown in the fluorescence spectra 150 and 530 is obtained. and lambda _{max 'may} fluoresce with, but in practice, laser oscillation device 720 without emitting a fluorescence spectrum 150 and 530, a wavelength longer than the stop band lambda _C lasing element 720, laser oscillation Converted light having a wavelength shorter than the stop band λ _B of the element 710 and having a wavelength λ _{emC ′} within the range of the reflection spectrum of the laser oscillation element 720 and the fluorescence spectrum 150 and / or 530 of the organic dye 510 (λ _{max ′} <λ _max <λ _{emC ′} <λ _{emB ′} ).

Similarly, when excitation light (wavelength λ _{ex ′} ) is incident on the laser oscillation element 730 of FIG. 8, the organic dye 510 of the laser oscillation element 730 absorbs the excitation light, and the maximum fluorescence wavelength λ _max shown in the fluorescence spectra 150 and 530 is obtained. and lambda _{max 'may} fluoresce with, but in practice, laser oscillation device 730 without emitting a fluorescence spectrum 150 and 530, a wavelength longer than the stop band lambda _D of the laser oscillation device 730, the laser oscillation Converted light (λ) having a wavelength shorter than the stop band λ _C of the element 720 and having a wavelength λ _{emD ′} within the range of the reflection spectrum of the laser oscillation element 730 and the fluorescence spectrum 150 and / or 530 of the organic dye 510 _{max ′} <λ _{emD ′} <λ _max <λ _{emC ′} ).

  It should be noted here that in the first embodiment using only a single organic dye 140, when an external force is applied until the particles 110 are in contact with each other, laser oscillation cannot be performed (laser oscillation element 330 in FIG. 4). By using the organic dye 510 of the seed, laser oscillation is possible even when an external force is applied until the particles 110 are in contact. That is, the tunability of laser oscillation can be expanded by combining organic dyes. The short wavelength side of the range of tunability of laser oscillation depends on the maximum fluorescence wavelength of at least one organic dye, and the long wavelength side depends on the range of the fluorescence spectrum of at least one organic dye.

  As described with reference to FIGS. 7 and 8, if the combination of the stop band and the organic dye is appropriately selected, the oscillation wavelength of the laser oscillation element made of the colloid crystal gel is controlled by controlling the stop band of the colloid crystal gel. Tunability can be expanded as well as tuneability is achieved. In the second embodiment, for the sake of simplicity, the organic dye 510 is described as being limited to two types of combinations. However, those skilled in the art can easily understand that the same applies to three or more types. obtain.

(Embodiment 3)
The third embodiment relates to a method for manufacturing the laser oscillation element described in the first and second embodiments.

  FIG. 9 is a diagram showing a flowchart for manufacturing a laser oscillation element made of a colloidal crystal gel according to the present invention.

  Step S910: Impregnating the colloidal crystal gel in which the particles are fixed with a network polymer with an ionic liquid and an organic dye. Here, the particles, the network polymer, the ionic liquid, and the organic dye are as described in the first and second embodiments. Here, the colloidal crystal gel to be impregnated with the ionic liquid and the organic dye may be dried or may contain a dispersion medium. In addition, when it contains a dispersion medium, it is existing arbitrary dispersion media, such as water and an organic solvent, except an ionic liquid. Colloidal crystal gels are described, for example, in JP-A 2006-124521, Sawada et al., Jpn. J. et al. Appl. Phys. 2001, 40, L1226, and Kanai et al., Adv. Funct. Mater. You may produce with reference to 2005, 15, 25 grade | etc.,. In order to distinguish the colloidal crystal gel impregnated with the ionic liquid and the organic dye according to the present invention from the colloidal crystal gel to be impregnated with the ionic liquid and the organic dye, hereinafter, the ionic liquid and the organic dye should be impregnated. The colloidal crystal gel is referred to as “conventional colloidal crystal gel”.

  In step S910, “impregnation” means any means for bringing the conventional colloidal crystal gel into contact with the ionic liquid and the organic dye. For example, the conventional colloidal crystal gel is immersed in the ionic liquid and the organic dye. For example, dropping an ionic liquid and an organic dye onto a conventional colloidal crystal gel. Preferably, the impregnation conditions are 1 hour to 14 days at room temperature in atmospheric pressure. As described above, according to the method of the present invention, the conventional colloidal crystal gel is impregnated with the ionic liquid and the organic dye, and the dispersion medium in the conventional colloidal crystal gel, the ionic liquid and the organic dye are spontaneously generated. The ionic liquid and the organic dye spontaneously permeate into a conventional colloidal crystal gel that does not contain a dispersion medium. As a result, laser oscillation elements 100 and 500 made of the colloidal crystal gel described with reference to Embodiments 1 and 2 are obtained.

  The ionic liquid and the organic dye are selected so that the stop band of the colloidal crystal gel obtained in step S910 is variable at least within a wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye and within the range of the fluorescence spectrum. Note that this is done. Since the laser oscillation device of the present invention can be produced by a one-step operation only by appropriately selecting the stop band of the colloidal crystal gel and the fluorescence spectrum of the organic dye, it is simple and advantageous.

  In addition, from a viewpoint of manufacturing efficiency, the impregnation may be performed while heating in step S910. Thereby, when the conventional colloidal crystal gel contains a dispersion medium, the volatilization of the dispersion medium is promoted, so that the replacement of the dispersion medium with the ionic liquid and the organic dye can be accelerated. The heating temperature varies depending on the type of the dispersion medium of the conventional colloidal crystal gel. For example, when water is used as the dispersion medium, a temperature range of 40 ° C. to 100 ° C. is preferable. Within this range, only the dispersion medium can be volatilized without disturbing the arrangement of the particles.

  Further, from the viewpoint of production efficiency, in step S910, the impregnation may be performed under a reduced pressure atmosphere or a dehumidified atmosphere. Thereby, when the conventional colloidal crystal gel contains a dispersion medium, the volatilization of the dispersion medium is promoted, so that the replacement of the dispersion medium with the ionic liquid and the organic dye can be accelerated. The pressure or humidity varies depending on the type of dispersion medium of the conventional colloidal crystal gel. For example, when water is used as the dispersion medium, a reduced pressure atmosphere of 4 kPa or less or a humidity range of 40% or less is preferable. If it is this range, compared with the environment of a normal pressure and a normal humidity, the effective effect is expected about acceleration | stimulation of volatilization of a dispersion medium. Of course, in step S910, the conventional colloidal crystal gel may be heated in a reduced pressure atmosphere or a dehumidified atmosphere.

  FIG. 10 is a diagram showing another flowchart for manufacturing a laser oscillation element made of a colloidal crystal gel according to the present invention.

  Step S910 in FIG. 9 preferably comprises two steps S1010 and S1020.

  Step S1010: A conventional colloidal crystal gel in which the dispersion medium is water is impregnated with an ionic liquid. Again, preferably, the impregnation conditions are 1 hour to 14 days at room temperature in atmospheric pressure. Further, as described above, the impregnation may be performed in a heating and / or reduced pressure / dehumidified atmosphere.

  Step S1020: Following step S1010, the colloidal crystal gel impregnated with the ionic liquid is further impregnated with the ionic liquid and the organic dye. Again, preferably, the impregnation conditions are 1 hour to 14 days at room temperature in atmospheric pressure.

  Thus, it is preferable to separate the impregnation of the ionic liquid and the organic dye into the conventional colloidal crystal gel in two stages, so that the organic dye can be prevented from precipitating. Organic dyes can have the property of being difficult to dissolve in water. Accordingly, by replacing the dispersion medium water and the ionic liquid in the conventional colloidal crystal gel in step S1010 in advance, the organic dye penetrates into the colloidal crystal gel without being precipitated in step S1020. A colloidal crystal gel containing an organic dye can be reliably obtained.

(Embodiment 4)
The fourth embodiment relates to a laser oscillation device using the laser oscillation element described in the first and second embodiments.

  FIG. 11 is a schematic diagram showing a laser oscillation apparatus according to the present invention.

  The laser oscillation device 1100 includes a light source 1110, a laser oscillation element 1120 that receives light emitted from the light source 1110 and converts the wavelength of the light, and stress applying means 1130 that applies stress to the laser oscillation element 1120.

The light source 1110 can be an arbitrary laser light source such as a solid-state laser using a semiconductor material or a crystal, a gas laser using a CO ₂ , or an ArF excimer, and emits light having a wavelength that can excite the organic dye employed in the laser oscillation element 1120. To emit.

  The laser oscillation element 1120 may be the laser oscillation element 100 or 500 described in the first and second embodiments.

  The stress applying means 1130 applies a stress in the film thickness direction of the laser oscillation element 1120 so as to control the lattice plane spacing of the particles 110 (FIGS. 1, 5, etc.) of the laser oscillation element 1120 and to change the stop band. Although not shown, the laser oscillation device 1100 may include a control unit such as a computer that controls the stress applying unit 1130. If the control unit has a relationship between the external force of the laser oscillation element 1120 and the stop band in advance, the laser oscillation element 1120 has a desired stop band, or the stop band of the laser oscillation element 1120 is linear. As control is facilitated as it changes, tunable laser oscillation is enabled.

  Next, the operation of the laser oscillation device 1100 will be described. Here, for simplicity, it is assumed that the laser oscillation element 1120 is similar to the laser oscillation element 100 described in the first embodiment.

The light source 1110 emits excitation light having a wavelength λ _ex . The wavelength λ _{ex of the} excitation light is a wavelength sufficient to excite the organic dye of the laser oscillation element 1120. The excitation light is incident on the laser oscillation element 1120, and the laser oscillation element 1120 receives the excitation light.

The organic dye of the laser oscillation element 1120 is excited by excitation light. Here, when the stress applying unit 1130 does not apply any stress to the laser oscillation element 1120 and the stop band of the laser oscillation element 1120 is λ _A , the wavelength λ _ex is converted into the wavelength λ _emA and output (FIG. 2). Or FIG. 4).

On the other hand, when the stress applying unit 1130 applies stress to the laser oscillation element 1120 and the stopband of the laser oscillation element 1120 is λ _C , the wavelength λ _ex is converted into the wavelength λ _emC and output (FIG. 4). In this manner, the laser oscillation device 1100 enables tunable laser oscillation by the stress applying unit 1130.

  The present invention will now be described in detail using specific examples, but it should be noted that the present invention is not limited to these examples.

  In Example 1, a laser oscillation element made of a colloidal crystal gel using 1-allyl-3-butylimidazolium halide as an ionic liquid and a rhodamine derivative as an organic dye was manufactured.

  First, a conventional colloidal crystal gel containing water as a dispersion medium is disclosed in Japanese Patent Application Laid-Open No. 2006-124521, Sawada et al., Jpn. J. et al. Appl. Phys. 2001, 40, L1226, Kanai et al., Adv. Funct. Mater. 2005, 15, 25.

The detailed procedure is as follows. A water-soluble suspension of monodispersed polystyrene particles (diameter 120 nm) was treated with an ion exchange resin, and a polycrystal structure of polystyrene was obtained in the suspension by deionization. Then, a water-soluble gel precursor of N-methylolacrylamide (0.70 M) and N, N′-methylenebisacrylamide (40 mM) was converted into 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propion. Amide] (0.35 mM) was added to the suspension along with the photoinitiator. Subsequently, the suspension was quickly poured into a flat capillary cell (thickness: about 100 μm) to form a colloidal crystal composed of a single crystal domain having a large area (100 cm ² ). A colloidal crystal is immobilized by a network polymer with a network structure in which water-soluble gel precursors in the colloidal crystal are cross-linked by photopolymerization, and the conventional colloidal crystal gel (self-organized and periodically arranged polystyrene particles are the network polymer). Colloidal crystal gel) was obtained.

  Next, the conventional colloidal crystal gel was impregnated with an ionic liquid and an organic dye (step S910 in FIG. 9). The ionic liquid was 1-allyl-3-butylimidazolium bromide (hereinafter referred to as ABImBr for simplicity) among 1-allyl-3-butylimidazolium halides. The organic dye was rhodamine 640 (hereinafter referred to as Rh for simplicity) among the rhodamine derivatives.

  Specifically, a conventional colloidal crystal gel was impregnated with ABImBr (step S1010 in FIG. 10). As a result, water as a dispersion medium in the conventional colloidal crystal gel was replaced with ABImBr. The impregnation was performed by immersing a conventional colloidal crystal gel cut into a circular sheet having a diameter of 3 mm in AbImBr at room temperature in the atmosphere for one week.

  Next, a mixed solution (0.25 wt% Rh) of ABImBr and Rh was impregnated in the colloidal crystal gel which was replaced with ABImBr and swollen (step S1020 in FIG. 10). ABImBr in the colloidal crystal gel was replaced with a mixed solution of ABImBr and Rh. The impregnation was performed by immersing the colloidal crystal gel in a mixed solution of AbImBr and Rh for 1 week at room temperature in the atmosphere. Thereafter, the colloidal crystal gel impregnated with ABImBr and Rh was exposed to a vacuum for several tens of minutes to remove the remaining dispersion medium (water). In this way, a laser oscillation element comprising a colloidal crystal gel containing an ionic liquid (ABImBr) and an organic dye (Rh) was obtained.

  About the laser oscillation element of Example 1, the optical measurement was performed using the optical microscope system.

  FIG. 12 is a schematic diagram showing an optical microscope system.

  The optical microscope system includes a laser oscillation device including a Q-switched Nd: YAG laser light source (Polaris II 20ST, New Wave Research) 1210, a laser oscillation element 1220, and a stress applying unit 1230. Specifically, the optical microscope system includes a dichroic mirror (Di1-R532-25 × 36, Semirock) 1201, a λ / 2 plate 1202, a Glan laser prism 1203, an imaging lens (U-TLU, Olympus) in addition to a laser oscillation device. ) 1204, a CMOS camera (Moticam2000, Shimadzu) 1205, a spectrometer 1206, a 100 W halogen lamp 1207, an electric lighting fixture for a microscope (BX-RLA 2, Olympus) 1208, and an objective lens (SLMPLanN × 20, Olympus) 1209.

  FIG. 13 is a schematic diagram showing stress applying means.

  12 includes a micrometer head 1310 that can be precisely controlled, a spring 1320, and a glass substrate 1330. The stress applying unit 1230 holds the laser oscillation element 1220 between the glass substrates 1330. Although two micrometer heads 1310 are shown in the drawing, actually, an external force is applied uniformly in the film thickness direction of the colloidal crystal gel of the laser oscillation element 1220 using three micrometer heads.

  The reflection spectrum of the colloidal crystal gel of the laser oscillation element was measured through an electric lighting fixture for microscope 1208 equipped with a halogen lamp 1207. The emission spectrum of the laser oscillation element was measured using SHG light (wavelength 532 nm) from the light source 1210. The pulse width of the light source 1210 was about 3 ns, and the repetition frequency was 10 Hz. SHG light from the light source 1210 propagates along the film thickness direction of the laser oscillation element 1220 as excitation light and is focused through the objective lens 1209. As a result, a circular spot having a diameter of about 40 μm was obtained on the surface of the laser oscillation element 1220. The collinearly transmitted emission spectrum from the laser oscillation element 1220 was measured by a spectrometer 1206 equipped with a charge coupled device (CCD) detector (SR-303i and iDus DU420A, Andor Technology). The laser oscillation beam quality was analyzed with a CCD beam profiler (BeamStar FX-33, Ophir). Reflection and emission color micrographs were recorded with a complementary metal oxide semiconductor camera.

  The external force dependence of the reflection microscope image, reflection spectrum, and stop band when an external force was applied to the laser oscillation element of Example 1 by the stress applying means 1230 was examined. The results are shown in FIG. 14 and FIG. The absorption spectrum of ABImBr was measured. The results are shown in FIG. The emission spectrum and the beam profile at that time when an external force was applied to the laser oscillation element of Example 1 by the stress applying means 1230 were measured. These results are shown in FIGS. The dependence of the emission line width and emission intensity on the excitation light energy (excitation energy) when an external force was applied to the laser oscillation element of Example 1 by the stress applying means 1230 was examined. The results are shown in FIG. The tunability of the emission spectrum when an external force was applied to the laser oscillation element of Example 1 by the stress applying means 1230 was measured. The results are shown in FIG.

  In Example 2, a laser oscillation element made of a colloidal crystal gel using 1-allyl-3-butylimidazolium halide as an ionic liquid and a combination of rhodamine derivatives as an organic dye was produced. The combination of organic dyes is Rh and sulfodamine B (hereinafter referred to as SR for the sake of simplicity) among rhodamine derivatives. ABImBr, Rh, and SR are substituted into ABImBr and swollen colloidal crystal gel. Since it is the same as that of Example 1 except impregnating the mixed solution (0.10 wt% Rh and 0.25 wt%), the description is omitted.

  The tunability of the emission spectrum and the microscope image of laser emission when an external force was applied to the laser oscillation element of Example 2 by the stress applying means 1230 were examined. These results are shown in FIG. 22 and FIG.

  In Example 3, as in Examples 1 and 2, ABImBr was mixed as ionic liquid with 4-dicyanomethylene-2-methyl-6 (p-dimethylaminostyryl) -4H-pyran (DCM) as an organic dye. A solution (0.25 wt% DCM) was prepared and its emission spectrum was measured. The results are shown in FIGS. 26 and 28.

Comparative Example 1

  In Comparative Example 1, the conventional colloidal crystal gel in Example 1 was left in the atmosphere for 24 hours, and the change was examined. The results are shown in FIG.

Comparative Example 2

  Comparative Example 2 was the same as Example 3 except that acetate-based 1-butyl-3-methylimidazolium acetate was used as the ionic liquid. Observation, absorption spectrum and emission spectrum of the mixed solution (0.25 wt% DCM) were examined. These results are shown in FIG. 25 and FIG.

Comparative Example 3

  Comparative Example 3 was the same as Example 3 except that acetate-based 1-ethyl-3-methylimidazolium acetate was used as the ionic liquid. Observation, absorption spectrum and emission spectrum of the mixed solution (0.25 wt% DCM) were examined. These results are shown in FIG. 27 and FIG.

For simplicity, Table 1 shows the experimental conditions of Examples 1 to 3 and Comparative Examples 1 to 3.

  FIG. 14 is a diagram illustrating the external force dependency of the stop band of the laser oscillation element according to the first embodiment.

  FIG. 14 shows changes in the stop band and changes in the reflection microscope image when an external force is applied in the film thickness direction of the laser oscillation element of Example 1 by the stress applying means 1230. In FIG. 14, the initial state is the state of the laser oscillation element of Example 1 before the external force is applied by the stress applying unit 1230. In the initial state, the laser oscillation element of Example 1 showed a stop band centered on 690 nm, and was dark brown according to the reflection microscope image.

  When an external force is applied stepwise to the laser oscillation element of Example 1 by the stress applying means 1230, the stop band shifts from 690 nm to the short wavelength side (blue shift), and finally reaches 558 nm in the maximum compression state. became. Similarly, the reflection microscope image changed from dark brown to orange to green. When the application of external force by the stress applying unit 1230 was removed, the stop band reversibly changed from 558 nm to 690 nm. From this, it was confirmed that the stop band of the laser oscillation element of Example 1 reversibly changes when an external force is applied.

  Even when an external force was applied to the laser oscillation element of Example 1 by the stress applying means 1230, only a single stop band was observed. This indicates that the periodic arrangement of polystyrene particles in the colloidal crystal gel is well maintained and no distortion or the like occurs in the laser oscillation element of Example 1 even when an external force is applied. .

Note that blue shift due to the external force of the stop band, lattice spacing d (see, for example, d _A to d _D in FIGS. 1 to 3) described in geometric reduction of.
λ = 2d√ (n ² −sin ² θ)
Here, λ is a stop band, d is a lattice spacing, n is an effective refractive index of the material, and θ is an angle of incident light.

  FIG. 15 is a diagram illustrating the relationship between the stop band and the compression rate of the laser oscillation element of Example 1.

In FIG. 15, the vertical axis represents the stop band λ _PBG (nm), and the horizontal axis represents the compression rate R _com in the film thickness direction of the laser oscillation element. R _com is defined as R _com = (T ₀ −T) / T ₀ . T ₀ and T are the film thicknesses of the laser oscillation element before compression and after compression, respectively. For example, R _com = 0.1 means that the film thickness of the laser oscillation element is reduced by 10%.

According to FIG. 15, it was found that the stop band decreases as the compression rate increases. Specifically, when the behavior of the stop band was analyzed using the least square method, it was expressed as λ _PBG = 686-406R _com . The correlation coefficient was 0.99. From this, it was confirmed that the stop band of the laser oscillation device according to the present invention is linearly shifted with respect to the compression rate, that is, the application of external force.

  According to FIG. 15 above, the laser oscillation element according to the present invention has the stopband variable because the particles in the colloidal crystal gel constituting the laser oscillation element are in a non-contact filling state. It was shown that.

  FIG. 16 is a diagram showing an absorption spectrum of the ionic liquid ABImBr used in Example 1.

  The absorption spectrum was measured using a solution in which ABImBr was dissolved in dichloromethane. It was confirmed that ABImBr has absorption at 228 nm, but has no absorption in the wavelength region of 280 nm or more.

FIG. 17 is a diagram showing a reflection spectrum and an emission spectrum of the laser oscillation element of Example 1 when the compression rate R _com = 0.1.

  A spectrum a in FIG. 17 is a reflection spectrum, a spectrum b is an emission spectrum at an excitation energy of 120 nJ / pulse, and a spectrum c is an emission spectrum at an excitation energy of 330 nm / pulse.

According to spectrum a in FIG. 17, the stop band of the laser oscillation element of Example 1 at R _com = 0.1 was 645 nm. This stop band was longer than the maximum fluorescence wavelength of Rh (about 610 nm) and within the range of the fluorescence spectrum of Rh (see the fluorescence spectrum of Rh in FIG. 21).

When the laser oscillation element of Example 1 at R _com = 0.1 is irradiated with excitation light (excitation energy: 120 nJ / pulse, focus diameter: about 40 μm) from the light source 1210, the emission spectrum b of FIG. 17 is obtained. It was. According to the emission spectrum b, the oscillation wavelength is 653 nm, which is longer than the stop band (645 nm) of the laser oscillation element of Example 1 at R _com = 0.1, and the laser oscillation element It was confirmed to be within the range of the reflection spectrum of Rh and the fluorescence spectrum of Rh.

When the laser oscillation element of Example 1 at R _com = 0.1 is irradiated with excitation light (excitation energy: 330 nJ / pulse, focus diameter: about 40 μm) from the light source 1210, the emission spectrum c of FIG. 17 is obtained. It was. According to the emission spectrum c, as the excitation energy increased, the emission intensity increased compared to the emission spectrum b, and a clearer emission peak was shown. The oscillation wavelength was 653 nm. Here again, the oscillation wavelength is longer than the stop band (645 nm) of the laser oscillation element of Example 1 at R _com = 0.1, and the reflection spectrum of the laser oscillation element and the fluorescence spectrum of Rh It was confirmed that it was within the range.

  According to FIG. 17, it was found that such a single laser emission peak can be obtained from a laser oscillation element made of a colloidal crystal gel by the PBG band edge effect through DOS enhancement of emitted photons.

Referring to the inset of FIG. 17, the line width (Δλ) of single laser oscillation was 0.06 nm. The quality factor (Q) of the cavity is expressed by Q = λ / Δλ (where λ is the wavelength of laser oscillation). The Q value calculated from the emission spectrum c was 1.09 × 10 ⁴ . This Q value was found to be the highest value among existing laser oscillation elements using colloidal crystals.

FIG. 18 is a diagram showing a three-dimensional beam profile of the laser oscillation element of Example 1 when the compression rate R _com = 0.1.
FIG. 19 is a diagram showing a one-dimensional beam profile of the laser oscillation element of Example 1 when the compression rate R _com = 0.1.

  The beam profiles shown in FIGS. 18 and 19 are both laser oscillations when the excitation energy is 330 nJ / pulse. 18 and 19, it was found that the laser oscillation (beam) by the laser oscillation element of Example 1 has a highly symmetric shape. The beam profile in FIG. 19 matched well with the theoretical Gaussian fitting at a high value of 91.2%. Such laser oscillation with excellent symmetry is caused by a colloidal crystal gel in which polystyrene particles are well arranged in the laser oscillation device according to the present invention. The narrow linewidth single mode lasing shown in FIG. 17 and the high beam quality shown in FIGS. 18 and 19 are advantageous for manufacturing next generation optoelectronic devices.

FIG. 20 is a graph showing the dependency of the emission intensity and line width of the laser oscillation element of Example 1 on the excitation energy when the compression rate R _com = 0.1.

In the laser oscillation element of Example 1 at the compression rate R _com = 0.1, the threshold excitation peak output for generating the laser feedback effect by examining the excitation energy dependence of the emission intensity and the line width of the laser oscillation wavelength of 653 nm. I found

When the excitation energy exceeded 170 nJ / pulse, the emission intensity increased significantly and the line width decreased from 45 nm to 0.06 nm. Therefore, the threshold excitation peak output was calculated as 4.5 MWcm ⁻² .

  17 to 20, in the laser oscillation device of the present invention, the stop band of the colloidal crystal gel constituting the laser oscillation element is longer than at least the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye, and the range of the fluorescence spectrum. If it is variable, the laser oscillation is longer than the stop band and within the stop band range.

  FIG. 21 is a diagram showing the tunability of the emission spectrum of the laser oscillation element of Example 1.

The emission spectra a to e are laser oscillations when the compression rate R _com is 0.09, 0.12, 0.15, 0.18, and 0.21, respectively. The fluorescence spectrum indicated by the dotted line is the fluorescence spectrum of Rh.

As the compression rate increased, that is, as the external force applied increased, the emission spectrum continuously shifted to the short wavelength side. Specifically, the emission peak of the emission spectrum shifted from 655 nm to 612 nm. All of the shapes of the emission spectra maintained a single excellent shape with symmetry. If the compression ratio R _com is in the range of 0.09 to 0.21, the stop band of the laser oscillation element of Example 1 is a longer wavelength region than the maximum fluorescence wavelength of the fluorescence spectrum of Rh, and , Within the range of the fluorescence spectrum (see, eg, FIG. 15).

When the compression rate R _com exceeded 0.21, the laser oscillation element of Example 1 did not oscillate. This is because when the compression ratio R _com exceeds 0.21, the stop band of the laser oscillation element of Example 1 is in a shorter wavelength region than the maximum fluorescence wavelength of the fluorescence spectrum of Rh (for example, FIG. 15). reference).

According to the laser oscillation element of Example 1, the laser oscillation wavelength can be appropriately tuned in the range of about 50 nm in the stop band range of 690 nm to 600 nm (corresponding to the compression ratio R _com in the range of 0 to 0.21). I understood.

  As shown in FIG. 21, in the laser oscillation device according to the present invention, the stop band of the colloidal crystal gel constituting the laser oscillation element is variable at least within the wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye and within the fluorescence spectrum range. Then, it was confirmed that the tunability of the laser oscillation wavelength can be achieved. Further, it has been found that such tunability of the laser oscillation wavelength can be easily achieved by the laser oscillation device included in the optical microscope system of FIG.

  FIG. 22 is a diagram showing the tunability of the emission spectrum of the laser oscillation element of Example 2.

In FIG. 22, emission spectra a to g are laser oscillations when the compression rate R _com is 0.09, 0.12, 0.15, 0.18, 0.21, 0.22 and 0.25, respectively. is there. The fluorescence spectrum A is a fluorescence spectrum obtained by mixing Rh and SR. Fluorescence spectra B and C are the fluorescence spectra of Rh and Sr, respectively.

  By adding SR to Rh, fluorescence spectra B and C became broad fluorescence spectra centered at 604 nm by energy transfer, as shown in fluorescence spectrum A.

As the compression rate increased, that is, as the external force applied increased, the emission spectrum continuously shifted to the short wavelength side. Specifically, the emission peak of the emission spectrum shifted from 655 nm to 588 nm. All of the shapes of the emission spectra maintained a single excellent shape with symmetry. Further, the stop band of the laser oscillation element of Example 2 is a longer wavelength region than the maximum fluorescence wavelength of the fluorescence spectrum B of Rh if the compression ratio R _com is in the range of 0.09 to 0.21. And if it is in the range of the fluorescence spectrum B and the compression ratio R _com is in the range of 0.22 to 0.25, it is a wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum C of SR, and Keio It was found to be within spectrum C.

When the compression rate R _com exceeded 0.25, the laser oscillation element of Example 2 did not oscillate. This is because when the compression ratio R _com exceeds 0.25, the stop band of the laser oscillation element of Example 2 is in a shorter wavelength region than the maximum fluorescence wavelengths of the fluorescence spectra B and C of either Rh and Sr. is there.

According to the laser oscillation element of Example 2, the extent stopband of 690Nm～580nm (corresponding to the range of the compression ratio _{R com} is 0-0.25), to be able to properly tune the lasing wavelength in the range of about 70nm I understood. Furthermore, as compared with FIG. 21, the tunability of the laser oscillation element of the second embodiment is wider than that of the first embodiment. That is, it was confirmed that the tunability of laser oscillation can be expanded by appropriately combining organic dyes.

  FIG. 23 is a view showing a microscope image of laser oscillation of the laser oscillation element of Example 2.

Microscope images at 655 nm, 610 nm, and 588 nm show laser oscillation of the laser oscillation element of Example 2 when the compression ratio R _com is 0.09, 0.21, and 0.25, respectively. According to FIG. 23, the laser emission color showed a clear change from dark brown to orange as the compression rate increased, that is, as the external force applied increased. When the external force of the stress applying unit 1230 was removed, the laser oscillation wavelength and the emission color returned to the initial state.

  22 and FIG. 23, the laser oscillation device according to the present invention has a stopband of the colloidal crystal gel constituting the laser oscillation element having a wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of at least one organic dye, and If it is variable within the range of the fluorescence spectrum, the tunability of the laser oscillation wavelength can be achieved, and the expansion of the tunability was confirmed by the combination of organic dyes. Further, it has been found that such tunability of the laser oscillation wavelength can be easily achieved by the laser oscillation device included in the optical microscope system of FIG.

  FIG. 24 is a diagram showing changes in the conventional colloidal crystal gel of Comparative Example 1.

  FIGS. 24A and 24B show the state immediately after the production of the conventional colloidal crystal gel of Comparative Example 1 and after standing in the atmosphere for 24 hours, respectively. As shown in FIG. 24A, immediately after manufacture, the conventional colloidal crystal gel showed a red structural color. However, as shown in FIG. 24 (B), after standing in the atmosphere for 24 hours, the red structural color of the conventional colloidal crystal gel disappeared and was transparent. This is because the colloidal crystal structure is distorted by evaporation of water, which is a dispersion medium in the conventional colloidal crystal gel. Although not shown in the drawings, the laser oscillation elements of Examples 1 and 2 of the present invention did not change in the structural color either immediately after production or when left in the atmosphere for 24 hours. From the above, it was confirmed that the laser oscillation device of the present invention uses an ionic liquid as a dispersion medium, and thus is stable for a long time without evaporation of the dispersion medium.

  FIG. 25 is a diagram showing an absorption spectrum of the mixed solution of Comparative Example 2.

  The mixed solution of Comparative Example 2 showed an absorption band unique to DCM at 500 nm or less as shown in the absorption spectrum of FIG. 25, but showed a dark brown color as shown in the inset of FIG. On the other hand, the mixed solution of Example 3 showed a red color (not shown). This indicates that some reaction occurred between the ionic liquid and DCM in the mixed solution of Comparative Example 2.

  FIG. 26 is a diagram showing an emission spectrum of the mixed solution of Example 3 and Comparative Example 2.

  The emission spectra a and b in FIG. 26 are the emission spectrum of the mixed solution of Example 3 and the emission spectrum of the mixed solution of Comparative Example 2, respectively. From FIG. 26, the mixed solution of Comparative Example 2 did not emit any light. On the other hand, the mixed solution of Example 3 showed light emission by DCM.

  FIG. 27 is a diagram showing an absorption spectrum of the mixed solution of Comparative Example 3.

  The mixed solution of Comparative Example 3 showed an absorption band unique to DCM at 500 nm or less as shown in the absorption spectrum of FIG. 27, but showed a dark brown color as shown in the inset of FIG. On the other hand, the mixed solution of Example 3 showed a red color. This indicates that some reaction occurred between the ionic liquid and DCM in the mixed solution of Comparative Example 3.

  FIG. 28 is a diagram showing an emission spectrum of the mixed solution of Example 3 and Comparative Example 3.

  The emission spectra a and b in FIG. 28 are the emission spectrum of the mixed solution of Example 3 and the emission spectrum of the mixed solution of Comparative Example 3, respectively. From FIG. 28, the mixed solution of Comparative Example 3 did not emit any light. On the other hand, the mixed solution of Example 3 showed light emission by DCM.

  According to FIGS. 25 to 28 described above, since the halogen-based ionic liquid having an allyl group at the terminal and DCM used for the colloidal crystal gel constituting the laser oscillation element of the present invention does not react at all, a stable laser is obtained. It was confirmed that oscillation was possible. Specifically, in the laser oscillation device of the present invention, 1-allyl-3-butylimidazolium halide, 1-allyl-3-ethylimidazolium halide, and 1,3-diallyl having an allyl group at the terminal are provided. It has been determined that a halogen system selected from the group consisting of butyl imidazolium halides is preferred.

  Since the laser oscillation element of the present invention uses an ionic liquid, it has excellent environmental resistance. Further, since the laser oscillation element of the present invention has continuous tunability, it is suitable for a variable laser. Further, the laser oscillation element of the present invention is extremely small and suitable for a micro laser. The laser oscillation device of the present invention is expected to be applied to a single minute light source, an optical amplifier, a low threshold laser oscillation device, a high brightness display, and the like.

100, 310, 320, 330, 500, 710, 720, 730, 1120, 1220 Laser oscillation element 110 particle 120 network polymer 130 ionic liquid 140, 510 organic dye 150, 530 fluorescence spectrum 160 reflection spectrum 200, 600 converted light DESCRIPTION OF SYMBOLS 1100 Laser oscillation device 1110, 1210 Light source 1130, 1230 Stress application means 1201 Dichroic mirror 1202 λ / 2 plate 1203 Grand laser prism 1204 Imaging lens 1205 CMOS camera 1206 Spectrometer 1207 100 W halogen lamp 1208 Microscope electric lighting device 1209 Objective lens 1310 Micrometer head 1320 Spring 1330 Glass substrate

International Publication WO2009 / 148082 Pamphlet

Shkunov et al., Adv. Funct. Mater. 2002, 12, 1, January Yamada et al., Adv. Mater. 2009, 21, 4134-4138

Claims (6)

A laser oscillation element comprising a colloidal crystal gel,
The colloidal crystal gel is
A polymer gel containing an ionic liquid and an organic dye;
Particles arranged in a self-organized manner in the polymer gel, wherein the particle arrangement includes particles in a non-contact packed state, and
The ionic liquid is hydrophilic and has an allyl group at the end,
The stop band of the previous SL colloidal crystal gel, located in fluorescence long wavelength than the maximum fluorescence wavelength of the spectrum of at least the organic dye, and, located within said fluorescence spectrum, the laser oscillation element. The ionic liquid is selected from the group consisting of 1-allyl-3-butylimidazolium halide, 1-allyl-3-ethylimidazolium halide, and 1,3-diallylbutylimidazolium halide. Item 2. The laser oscillation element according to Item 1 .   The organic dye is at least one selected from the group consisting of rhodamine derivatives, oxazine derivatives, fluorescein derivatives, coumarin derivatives, styryl derivatives and 4-dicyanomethylene-2-methyl-6 (p-dimethylaminostyryl) -4H-pyran (DCM). The laser oscillation element according to claim 1, wherein the laser oscillation element is selected. It is a manufacturing method of the laser oscillation element in any one of Claims 1-3, Comprising :
Impregnating a colloidal crystal gel in which self-organized periodic arrayed particles are immobilized by a network polymer with an ionic liquid and an organic dye,
In the ionic liquid and the organic dye, the stop band of the colloidal crystal gel obtained by the impregnation step is positioned at least in a wavelength region longer than the maximum fluorescence wavelength of the fluorescence spectrum of the organic dye, and A method that is selected to be within range. The impregnating step comprises:
Impregnating the colloidal crystal gel swollen with water with an ionic liquid;
Comprising a step of further impregnating the ionic liquid and an organic dye in the colloidal crystal gel swollen with the ionic liquid, the method of claim 4. The method according to claim 4, wherein the impregnating step impregnates the colloidal crystal gel with an ionic liquid and an organic dye for 1 hour to 14 days.