JP3259754B2 - Optical element and method for producing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element, and more particularly to an optical element for directly controlling an electromagnetic wave by an electromagnetic wave and a method for producing the same. 2. Description of the Related Art Generally, since electromagnetic permittivity is linear, electromagnetic waves do not directly interact with each other. For this reason, it is extremely difficult to directly control electromagnetic waves by electromagnetic waves. Such direct control has a nonlinear dielectric constant such as KTP (potassium titanate phosphate) under special conditions where the energy density of the electromagnetic waves is extremely high. This is done only with crystals. [0003] However, the above KTP
Has a problem that it operates only in special situations where the optical electric field is extremely high because of its low nonlinearity. An object of the present invention is to provide an optical element capable of directly controlling an electromagnetic wave emitted by an electromagnetic wave in view of the above prior art. [0005] The structure of the present invention that achieves the above object has the following features. 1) A substance having a periodic permittivity distribution and having therein a substance capable of emitting an electromagnetic wave having a wavelength confined by the cycle as fluorescence or phosphorescence, and the substance can be transitioned by the electromagnetic wave.
Excluding the ground level is a two-level excited level
In both cases, relative to the ground state by irradiation of the first electromagnetic wave
Transitions to the lower excitation level, and further to this lower excitation level
Amount of electromagnetic wave emitted when transitioning from to the ground level
Between the lower excitation level and the higher excitation level
Irradiating a second electromagnetic wave corresponding to the excitation energy
It is configured to be controlled by . 2) The dielectric constant distribution is periodic, and contains a substance capable of emitting an electromagnetic wave having a wavelength confined by the period as fluorescence or phosphorescence therein, and the substance can be transitioned by the electromagnetic wave.
Are excited levels of three or more levels, excluding the ground level.
And from the ground state to the middle by irradiation of the first electromagnetic wave.
Transition to the intermediate level, and from this intermediate level to the lower level
After transitioning to the ground level,
The amount of magnetic wave is compared with the lower excitation level and the intermediate level.
Second energy corresponding to the excitation energy of the higher excitation level
It is configured to control by irradiating the electromagnetic wave of
That . 3) The optical element according to 2 ) above, wherein the intermediate
Level and the lower level are the same level. 4) The optical element according to any one of 1) to 3 ) above
In the semiconductor device, the periodic structure has a missing period or another period is subjected to a change in dielectric constant to form a period disorder. 5) Irradiation of a laser light interference fringe to a mixture of a photocurable resin, a translucent substance, and a dye that generates fluorescence or phosphorescence causes a periodic dielectric constant distribution, and a wavelength confined by the cycle. To produce an optical element capable of emitting the electromagnetic waves as fluorescence or phosphorescence. In the present invention having the above structure, an object whose dielectric constant periodically changes in space reflects an incident electromagnetic wave of a specific wavelength. In particular, when incident in the periodic direction, the electromagnetic wave is reflected most efficiently when the wavelength is equal to twice the optical path length of one period. [0007] In particular, in the invention of 1), since a substance that emits electromagnetic waves having a wavelength that does not pass through the periodic structure is emitted as fluorescent light, the generated fluorescent light is reflected by this cycle and cannot go out of the element. . That is, a strongly localized (confined) state can be realized. In the confined state, the electric flux density increases, so that interaction between electromagnetic waves can be realized. At the same time,
And the lower two photoexcitable levels
Energy difference between the ground state and the first excited state
First excitation state when the energy of the existing electromagnetic wave
The electromagnetic wave of energy corresponding to the excitation from the state
And that electrons in the first excited state are further excited
It is reduced by As a result, localized electromagnetic waves are reduced.
Can be reduced. In other words, the electromagnetic wave
The amount can be controlled. [0010] In particular, in the invention of 2) , the light is transmitted through the periodic structure.
Contains a substance that emits electromagnetic waves with
The generated fluorescence is reflected by this cycle and
You will not be able to get out of your child. In other words, it is strongly localized
(Confined) state can be realized. Trapped
In the state where the electromagnetic waves are high, the electric flux density is high.
The effect can be realized. At the same time, since a substance having three or more levels capable of photoexcitation is mixed, when the energy difference between the ground state and the first excited state corresponds to the energy of the localized electromagnetic wave, When an electromagnetic wave having energy corresponding to the excitation is incident, the electrons in the first excited state are reduced by being excited further.
As a result, the localized electromagnetic waves can be reduced. That is, the amount of the electromagnetic wave can be controlled by the electromagnetic wave. Such an operation and effect can be similarly obtained in the invention 3). In the invention of 4) , by generating disturbance of the periodic structure, photons can be confined in a narrower region. Therefore, higher efficiency and lower threshold can be achieved. Embodiment 1 FIG. 1 is a schematic diagram showing an optical element according to this embodiment, (a) is a schematic diagram showing its structure and operation,
(B) is a schematic diagram showing an energy level of a substance that emits fluorescence. As shown in FIG. 1, the optical element according to the present embodiment is constituted by a high dielectric constant region 101 and a low dielectric constant region 102 which are present periodically. In this embodiment, the change in the refractive index is discrete, but may be continuous or may be substantially periodic.
Two or more periods may be superimposed. In addition, the one-dimensional period is displayed and written, but the two-dimensional or FIG.
A three-dimensional lattice structure as shown in FIG. In the structure as described above, a substance having an energy level as shown in (b) is mixed. In the figure, 111 indicates a ground level, and 112 indicates an excitation level. Arrow 115 indicates a transition when a photon corresponding to the energy difference (excitation energy) between the ground level and the excitation level is absorbed, and arrow 116 indicates a transition when a photon is emitted as fluorescence. The period is adjusted so that the wavelength of the fluorescent light 116 is confined by the periodic structure. In this embodiment, when light 120 having a wavelength corresponding to the excitation energy is irradiated, the fluorescent light 116 generated by the irradiation is localized in the region 112. Outgoing light 121
Are harmonics generated by the dielectric nonlinearity of the optical element. When the thickness is about the localization length or the nonlinearity is small, the light having the same wavelength as the localized light is narrowed and emitted. <Embodiment 2> FIGS. 3A and 3B are schematic views showing an optical element according to the present embodiment. FIG. 3A is a schematic view showing the structure and operation of the optical element, and FIG. It is a schematic diagram showing an energy level. As shown in FIG. 1, the optical element in the present embodiment is constituted by a high dielectric constant region 201 and a low dielectric constant region 202 which are present periodically. In this embodiment, the change in the refractive index is discrete, but may be continuous or may be substantially periodic.
Two or more periods may be superimposed. In addition, the one-dimensional period is displayed and written, but the two-dimensional or FIG.
A three-dimensional lattice structure as shown in FIG. In the structure as described above, a substance having an energy level as shown in (b) is mixed. In the figure, reference numeral 211 denotes a ground level;
3 indicates an excitation level. An arrow 215 indicates a transition when a photon corresponding to an energy difference (excitation energy) between a ground level and an excitation level is absorbed, and an arrow 216 indicates a transition when a photon is emitted as fluorescence. Arrow 217 indicates a transition between excited levels. Then, the life of the level 213 is changed to the level 212.
In addition to using a device shorter than the above, the device is formed with a period such that the fluorescent light 216 is confined by the periodic structure. That is, a substance that is excited at a wavelength different from the fluorescence 216 is used as the substance in this embodiment. In this embodiment, when the light 220 having the wavelength corresponding to the excitation of the arrow 215 is irradiated, the fluorescence generated by the irradiation is localized in the region 222. The outgoing light 221 is
Harmonics generated by the dielectric nonlinearity of the optical element are emitted. When the thickness is about the localization length or the nonlinearity is small, the light having the same wavelength as the localized light is narrowed and emitted. Further, in this embodiment, a substance excited at a wavelength different from that of the fluorescent light 216 is used, and the light 220 is not reflected by the periodic structure, so that light can be incident from any direction. In addition, since stimulated emission does not occur due to the light 220, emitted light having high coherence can be obtained. <Embodiment 3> FIGS. 4A and 4B are schematic views showing an optical element according to an embodiment, in which FIG. 4A is a schematic view showing the structure and operation of the optical element, and FIG. FIG. As shown in the figure, the optical element in this embodiment is constituted by a high dielectric constant region 301 and a low dielectric constant region 302 which are present periodically. In this embodiment, the refractive index change is discrete, but may be continuous, or may be substantially periodic.
Two or more periods may be superimposed. In addition, the one-dimensional period is displayed and written, but the two-dimensional or FIG.
A three-dimensional lattice structure as shown in FIG. In the structure as described above, a substance having an energy level as shown in (b) is mixed. In the figure, reference numeral 311 denotes a ground level;
3,314 shows an excitation level. An arrow 315 indicates a transition when a photon corresponding to an energy difference (excitation energy) between a ground level and an excitation level is absorbed, and an arrow 316 indicates a transition when a photon is emitted as fluorescence. Arrow 317,3
Reference numerals 18 and 319 indicate transitions between excited levels. Then, a lifetime of the level 313 which is shorter than that of the level 312 is used. In this embodiment, when the light 320 having the wavelength corresponding to the excitation of the arrow 315 is irradiated, the fluorescent light generated by the irradiation is localized in the region 322. The outgoing light 321 is
Harmonics generated by the dielectric nonlinearity of the optical element are emitted. When the thickness is about the localization length or the nonlinearity is small, the light having the same wavelength as the localized light is narrowed and emitted. Here, when light corresponding to the excitation of the arrow 318 is irradiated, the number of levels 312 depending on the light intensity is reduced, and the amount of fluorescence is reduced. That is, the intensity of the emitted light is made variable by the third light 323, and the operation like a transistor can be realized. In this embodiment, as in the first embodiment, one of the levels 312 and 313 may be shared. The high refractive index 601 and the low refractive index substance 602 shown in FIG.
A structure in which a period is omitted (disordered) or a structure in which a change in the dielectric constant in another period shown in FIG. By generating such disturbance 603, photons can be confined in a narrower region, so that higher efficiency and lower threshold can be realized. Further, the excitation levels shown in the embodiments are only those relating to the function of the element, and other levels may be present. Further, in Examples 1 to 3, FIG.
(B), the place where the substance having the energy level as shown in FIG. 3 (b) and FIG. 4 (b) is mixed is arbitrary. The operating principle in this case is the same as in the first to third embodiments. As the material for the high / low dielectric constant region,
Polymer resins, liquid crystals, glass, etc., can be used as long as they do not have light absorption at the wavelength used, and as a material showing an energy level, any dye that emits fluorescence can be used. Dyes for dye lasers are preferred. <Embodiment 4> FIG. 6 is a schematic view showing a method for producing an optical element of the present invention. As shown in the figure, an optical element according to an embodiment of the present invention is a mixture 401 of a photocurable resin, a translucent substance, and a dye that is a substance that generates fluorescence.
Is irradiated with interference fringes of laser beams 402 and 403. In such an optical element, the resin is polymerized in a portion where the interference fringe intensity is high, and the other region becomes a translucent material region and is realized by the one-dimensional periodic structure 411. By changing the interval between the laser beams 402 and 403, the period can be arbitrarily changed with a length equal to or longer than the wavelength of the laser beam. 70% of visible light curable resin and liquid crystal (E-7)
Argon ion laser light (488 nm) was introduced into a mixture of 30% and rhodamine 6G for laser into a glass cell composed of two glass plates, and irradiated from two directions through a prism. The angle of the two light beams is 600 nm in the glass cell.
In order to confine the light, the interval between the interference fringes was set to about 100 nm. When the device thus produced was irradiated with light from an argon ion laser (514.5 nm), light emission with a narrow spectral line width at about 600 nm and a doubled solution thereof could be observed. 560n
When light corresponding to the energy difference between the singlet and the first excited state of the singlet of m rhodamine 6G was incident, the amount of emitted light changed. Further, by applying an electric field using a glass plate provided with a transparent electrode, the localization state was changed and the amount of emitted light could be changed. Furthermore, by changing the temperature, the refractive index of the liquid crystal was changed, and the localized state was changed, the amount of emitted light could be changed. In this embodiment, rhodamine 6G is used as a dye.
However, the present invention is not limited to this. Further, in the present embodiment, liquid crystal is used, but the present invention is not limited to this as long as the system performs phase separation by optical interference. Further, in the present embodiment, light interferes from two directions. However, a three-dimensional periodic structure may be created by interfering light beams in four directions and six directions or more. Further, the glass plate only needs to have translucency, and may be an acrylic plate, a PET film, or the like. As shown in FIG. 7, a two-dimensional periodic structure 511 can be realized by irradiating the mixture 501 with laser light 502 from four directions. Further, by increasing the number of laser beams 502, a three-dimensional periodic structure can be realized. In this example, the example of the cubic lattice is shown, but a periodic structure such as a triangular lattice may be used. When liquid crystal is used as the translucent substance, good phase separation can be obtained due to the difference between the liquid phase and the liquid crystal phase. here,
When the orientation of the liquid crystal is controlled by applying a pressure or an electromagnetic field that changes the temperature, the degree of localization of light changes and the element characteristics can be changed from the outside. As described above in detail with the embodiments, according to the present invention, it is possible to realize an optical element for directly controlling an electromagnetic wave by a high-efficiency low-threshold electromagnetic wave. Also, by using a structure in which substances with different dielectric constants are dispersed,
A variable element, that is, an element having flexibility can be realized. An element having a larger area can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an optical element according to Example 1 of the present invention, wherein (a) shows its structure and operation, and (b) shows an energy level of a substance which emits fluorescence. Is shown. FIG. 2 is a schematic diagram showing an optical element according to the present invention having a three-dimensional lattice structure. FIGS. 3A and 3B are schematic diagrams showing an optical element according to Example 2 of the present invention, wherein FIG. 3A shows the structure and operation thereof, and FIG. FIGS. 4A and 4B are schematic diagrams showing an optical element according to Example 3 of the present invention, wherein FIG. 4A shows the structure and operation thereof, and FIG. FIG. 5 is a schematic diagram showing an optical element according to a further modification of the first to third embodiments. FIG. 6 is a schematic view showing a method for producing an optical element of the present invention. FIG. 7 is a schematic view showing another method for producing the optical element of the present invention. [Description of Signs] 101, 201, 301 High permittivity regions 102, 202, 302 Low permittivity regions 111, 211, 311 Ground levels 112, 212, 213, 312, 313, 314 Excitation levels 120, 220, 320 , 323 Irradiation light 121, 221 and 321 Emission light

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-327109 (JP, A) JP-A-6-152070 (JP, A) JP-A-7-249816 (JP, A) RADIC, et. al. , Theory of low-threshold optical switching in nonlinear phase-shifted periodic dic structures, Optical Society of America. 12, No. 4, pp. 671-680 ZHAO, et. al. , COMPARATIVE STUDY OF ONE-DIMENSIONAL PH OTONIC BANDGAP STR ACTURES USING MULT ILAYER NONLINERAR THIN FIL, Journal of Non-Personal Optical Medical. 4, No. 1, pp. 1-11 (58) Fields surveyed (Int. Cl. ⁷ , DB name) G02F 1/35 H01S 3/109 JICST file (JOIS)

Claims (1)

(57) [Claims 1] A substance having a periodic permittivity distribution and capable of emitting, as fluorescence or phosphorescence, an electromagnetic wave having a wavelength confined by the period, wherein the substance is an electromagnetic wave. By
Levels that can be transitioned are two levels of excited levels, excluding the ground level
And the irradiation of the first electromagnetic wave relatively lower than the ground state.
Transition to the excited level, and from this lower excited level
The amount of electromagnetic waves emitted at the time of transition to the level is determined by the excitation between the lower excitation level and the higher excitation level.
By irradiating a second electromagnetic wave corresponding to energy
An optical element characterized in that the optical element is configured to be controlled . 2. A substance having a dielectric constant distribution that is periodic and capable of emitting an electromagnetic wave having a wavelength confined by the period as fluorescence or phosphorescence therein, wherein the substance is generated by the electromagnetic wave.
Excitable three or more levels except for the base level
Transition from the ground state to an intermediate level by the irradiation of the first electromagnetic wave.
And then transitioned from this intermediate level to a lower level
Later, the amount of electromagnetic waves emitted when transitioning to the ground level
With the lower excitation level and the excitation higher than the intermediate level.
Irradiation of the second electromagnetic wave corresponding to the excitation energy with the level
An optical element characterized in that the optical element is configured to be controlled by performing the following. 3. The optical element according to claim 2, wherein
The intermediate level and the lower level are the same level
Wherein the optical element. 4. Any one of claims 1 to 3
The optical element according to any one of claims 1 to 3, wherein the periodic structure has a period missing or a period is formed by adding a change in dielectric constant to another period to form a disorder of the period. 5. A dielectric constant distribution is periodic by irradiating a laser light interference fringe to a mixture of a photocurable resin, a translucent substance, and a dye that is a substance that generates fluorescence or phosphorescence,
A method for producing an optical element, comprising producing an optical element capable of emitting, as fluorescence or phosphorescence, an electromagnetic wave having a wavelength confined by the period.