JP3005625B2 - Optical property evaluation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating optical properties of an optical element. More specifically, the present invention relates to an optical property evaluation method useful for evaluating optical properties of a highly functional optical element used for a wavelength selective transmission film, a reflection film, an optical nonlinear effect film, a photoelectric conversion device, and the like.

[0002]

2. Description of the Related Art A conventional optical element used for a wavelength selective transmission film, a reflection film, an optical nonlinear effect film, a photoelectric conversion device, or the like has an electrode in the element and uses an electric signal for input / output. However, since optical information processing of signal light incident by photoelectric conversion is performed, there is a drawback that there is a limit in increasing the response speed of the element and increasing the integration density. For this reason,
The progress of optical technology and optoelectronic technology using these conventional optical elements has been hindered. Under such circumstances, a high-performance optical element capable of performing optical information processing without photoelectric conversion in the element, that is, control for controlling and assisting the operation of the incident signal light and the optical element. It is desirable to use an optical element capable of performing optical information processing using only light such as light or auxiliary light, and capable of performing one optical information processing within one unit element. I was

However, in order to actually develop and use this highly functional optical element, the optical properties of the element and the element material must be changed by the spatial movement of the light response state such as light emission and light absorption with respect to incident signal light. Need to be evaluated by detecting as a function of time or spectrum. Conventional methods for evaluating the optical properties of optical elements include a method of evaluating a flat-type element by irradiating a single light beam, a method of evaluating the emission intensity distribution of an optical fiber in an element cross-section, and the like. A method of evaluating by detecting a still image of a part that responds to light such as light emission by irradiating the whole with ultraviolet light, and detecting uneven parts from a still image of absorbed light by irradiating the whole element with white light However, at present, all methods can only evaluate the static optical response state of the optical element, and the dynamic optical response state, that is, the spatial movement of the optical response state Could not be evaluated.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and provides a new optical property evaluation method capable of evaluating the spatial movement of the optical response state of an optical element. It is intended to be.

[0005]

According to the present invention, as a means for solving the above-mentioned problems, a minute area in a solid sample plane is
Excitation by energy beam irradiation to generate a first excited state, and before the first excited state disappears or attenuates, irradiates a region including the minute region and having a wider planar area with light. 2nd higher by
An optical property evaluation method is characterized in that an excited state is generated, and light emitted upon transition from the second excited state to the first excited state or the ground state is detected.

Further, according to the present invention, a small region in a plane of a solid sample is excited by irradiating an energy beam to generate a first excited state, and the first excited state disappears.
Alternatively, before attenuating, a higher second excited state is generated by irradiating a white light to an area including the minute area and having a wider plane area, and the transition from the first excited state to the second excited state is performed. Provided is a method for evaluating physical properties of light, which comprises detecting light absorbed by the light.

[0007] The present invention provides the above method,
One of the modes is to detect light emission or absorption light by time-resolved spectroscopy by irradiation with pulsed light, or to detect light emission or absorption light by spectral analysis.
More specifically, in the optical property evaluation method of the present invention, the surface of a solid sample or a minute region having a diameter of several microns in the plane of a thin film sample is irradiated with an energy beam such as light, electron beam, radiation, or X-ray. To generate a first excited state, and before the first excited state disappears or attenuates and returns to the ground state, a region including a minute region and having a wider plane area is defined as (a )
When light emission is detected, light irradiation is performed. (B) When absorption light is detected, white light irradiation is performed to excite the light to a higher state to generate a second excited state. At the time of generation of this excited state, if the generated excited state moves spatially with the lapse of time immediately after the excitation, not only the light emission or absorption light in the minute region where the first excited state is generated, but also this minute state Light emission or absorption light in an area different from the area, that is, an area including the minute area and having a wider plane area is detected. When the generated excited state does not move spatially with the passage of time immediately after the excitation, only light emission or absorbed light in the minute region where the first excited state is generated is detected. In this way, by changing the irradiation area range at the time of each state excitation, and detecting light emission or absorption light at the time of state transition, the space movement process of the excited state, that is, the space movement process of the optical response state of the optical element, is performed. Can be evaluated.

In addition, a time-resolved spectroscopic analysis is performed by irradiating a pulse light having a pulse width of milliseconds or more to femtoseconds or more to light emission or absorption light at the time of a state transition, so that the time lapse of the light response state can be reduced. The accompanying spatial movement process can be detected as a time-resolved moving image, that is, an image in a light response state as a continuous still image as a function of time. Furthermore, by analyzing the light emission or absorption light at the time of the state transition, the spatial movement process with the lapse of time of the light response state is analyzed by a spectrum decomposition moving image, that is, the image of the light response state is converted into a function of the spectrum. Can be detected as a continuous still image.

[0009]

According to the present invention, as described above, the region in which the second excited state is generated is a region having a wider plane range including the region in which the first excited state is generated, The spatial movement process of the light response state can be evaluated by detecting the light emission or absorption light, and the light response can be evaluated by detecting the light emission or absorption light by using time-resolved spectroscopy by pulsed light irradiation. The spatial movement process of the state can be obtained as a time-resolved moving image, and the spatial movement process of the light response state can be obtained by detecting the emission or absorption light by performing spectrum analysis. Can be obtained as a moving image.

As described above, since the spatial movement process of the optical response state of the optical element to the incident signal light can be evaluated, various high-speed and high-density optical information processing of the incident signal light using only the light can be performed. Highly functional optical elements can be developed and used. For example, an aggregate formed from a single atom or a single molecule in the device is dispersed as a photofunctional aggregate,
It is possible to develop an optical element that uses, as an optical information processing means, a spatial movement process of a light response state of each unit light functional aggregate to an incident signal light to another unit light functional aggregate. In addition, the spatial movement process of the optical response state in such an optical element is performed by using one or two or more kinds of light having the same wavelength as the incident signal light from the outside of the element or having a different wavelength.
The control can be performed by irradiating the optical element plane coaxially with the incident signal light or from a different angle, and the intensity of the signal light required to generate the excited state (optical response state) can be reduced. That is, by using the optical property evaluation method of the present invention, only the incident signal light and the light of the operation of the optical element, that is, the control light or the auxiliary light for controlling and assisting the spatial movement process of the optical response state are used. Thus, an optical element capable of performing optical information processing can be developed, so that the optical response speed of the optical element can be increased and the integration density can be increased.

In the optical property evaluation method according to the present invention, when the aggregates are dispersed in the element as described above, the aggregates are dispersed in a regular array, for example, in a three-dimensional lattice array, so that the phase of the incident signal light can be reduced. The state can be controlled, and information on the phase can be applied to an optical element used for optical information processing. In addition, by adjusting the values of the intensity, wavelength, pulse width, phase, etc. of the incident signal light, the excitation state in the element, that is, the optical response state, is controlled, and the arithmetic architecture of the element is changed. A non-von Neumann-type operation architecture can be used instead of a type-type operation architecture. That is, for one input signal to the logic circuit, the output signal is not uniquely determined by the designed element configuration, but the operation method is determined by the input signal.
Optical elements with different output signals can be developed. Further, when an image having wavelength information and time information is input into the element, an optical element can be developed in which the way of responding to an input signal in the element differs depending on the input wavelength band.

[0012]

The present invention will be described below in more detail with reference to examples. Of course, the present invention is not limited by the following examples. (Example 1) 3,3'-dieth which is a cyanine dye
yloxadicarbocyanine iodid
The optical properties of a 30 μm-thick thin film sample in which e was dispersed in a polymer at a concentration of 0.02 mol were evaluated by detecting light emitted at the time of state transition.

FIG. 1 shows an example of the structure of the optical property evaluation apparatus used in this embodiment. Sample (11) is a 3,3′-diethyloxadi cyanine dye.
Carbocyanine iodide to 0.02
It is dispersed in a polymer at a concentration of mol, and has a thickness of 30 μm. Wavelength 58 generated by a combination of a Q-switched Nd: YAG laser and a dye laser
Excitation light (14) having a wavelength of 0 nm and a pulse width of 6 nanoseconds is incident on an optical microscope (1) by a light incidence mechanism (2), and this light is irradiated on a small area with a diameter of 5 μm in the plane of the thin film sample (11). This minute region is excited to generate a first excited state. Since the state lifetime of this first excited state is about 2 nanoseconds, the second excited state must be generated within 2 nanoseconds after excitation. Therefore, 0.5 nanoseconds after excitation, Q
An excitation light (15) having a wavelength of 500 nm and a pulse width of 6 nanoseconds generated by a combination of a switch Nd: YAG laser and a dye laser is incident on an optical microscope (1) by a light incidence mechanism (3), and this light is passed through a A region having a diameter of 500 μm including a minute region having a diameter of 5 μm in which one excited state is generated is irradiated, and this region is excited to generate a second excited state. Then, light (emission) emitted when the second excited state transits to the first excited state or the ground state is condensed by the optical microscope (1) through the objective lens (10), and is focused on the optical microscope (1). The optical filter (4) installed removes the excitation light (14) (15) and efficiently transmits only light emission to generate a light emission image, and the amplification device (5) amplifies the light intensity of the light emission image. Is performed, and the light emission image is converted into an electric signal by the photoelectric conversion device (6), and 2
The image is converted into a two-dimensional image and displayed on the display device (7).

Further, the emission image transmitted through the optical filter (4) is time-resolved about every 5 nanoseconds by a gate mechanism attached to the amplifier (5). That is, the trigger signal is sent to the gate mechanism of the amplifier (5) with the moment of excitation from the ground state to the first excitation state as the origin of time, and only the emission image every 5 nanoseconds after the excitation is taken out to obtain the emission image time. An image of decomposition, that is, an emission image for each time is observed. This makes it possible to evaluate the concentration, the moving speed, and the direction of the excited state over time. FIG. 2 shows 5 ns, 10 ns, 15 ns, 20 ns,
FIG. 4 shows a two-dimensional image of a luminescence image time-resolved in 25 nanoseconds, where (21) is a luminescence image after 5 ns, and (22)
Is the emission image after 10 nanoseconds, (23) is the emission image after 15 nanoseconds, (24) is the emission image after 20 nanoseconds, and (25) is 2
It is an emission image after 5 nanoseconds. From FIG. 2, it can be seen that the emission image spreads concentrically over time. This indicates that the cyanine dye is isotropically dispersed in the polymer of the sample. A part of the emission image is distorted, which is due to the influence of impurities such as dust in the sample or a part where the dispersion of the cyanine dye is uneven.

In the case where the time resolution is performed at shorter intervals, the time resolution is converted by converting the time axis into a spatial axis by deflecting an incident electron beam by a high-speed electric field swept at a high speed after photoelectrically converting an incident photon. Time and minute change device (8)
Is disposed between the amplifying device (5) and the photoelectric conversion device (6) as needed, so that the time can be resolved in the order of picoseconds. It can be carried out.

(Example 2) 3,3 'which is a cyanine dye
-Diethyloxadicarbocyanine
The optical properties of a thin film sample having a thickness of 30 μm in which iodide was dispersed in a polymer at a concentration of 0.02 mol were evaluated by detecting light absorbed during a state transition.

In the apparatus shown in FIG. 1, the Q switch Nd: Y
Excitation light (1 nm) having a wavelength of 580 nm and a pulse width of 6 ns generated by a combination of an AG laser and a dye laser.
4) is incident on the optical microscope (1) by the light incidence mechanism (2), and this light is applied to a small area having a diameter of 5 μm in the plane of the thin film sample (11) to excite this small area to the first excited state. Is generated. 0.5 nanoseconds after the first excitation, the white light incident mechanism (9) irradiates a region of 500 μm in diameter including a small region of 5 μm in diameter where the first excited state is generated to excite the region. To generate a second excited state. This white light may be continuous white light emitted from a mercury lamp, xenon lamp, or halogen lamp, or white light generated by irradiating a laser having a pulse width of about a picosecond to water contained in a quartz cell. Light pulses can be used. The light absorbed when the excited state is generated is condensed by the optical microscope (1) through the objective lens (10), and is excited by the optical filter (4) installed on the optical microscope (1). 14)
By eliminating (9) and efficiently transmitting only the absorbed light, an absorbed light image is generated, and the intensity of the absorbed light image is amplified by the amplifier (5), and then the light is amplified by the photoelectric converter (6). It is converted into an electric signal and displayed on the display device (7).

The time resolution of the absorption light image is time-resolved about every 5 nanoseconds by the gate mechanism attached to the amplifier (5), similarly to the time resolution of the emission image in the first embodiment. Furthermore, the same time-resolver (8) as in the first embodiment
Is disposed between the amplifying device (5) and the photoelectric conversion device (6), the time can be resolved to about picoseconds.
In this manner, the time-resolved image of the absorbed light allows observation of the absorption image at each time, so that the concentration, the moving speed, and the direction of the excited state can be evaluated.

(Embodiment 3) FIG. 3 shows a structural example of an optical property evaluation apparatus for irradiating a sample with excitation light using an optical fiber. The tip of the quartz optical fiber is processed into a radius of curvature of several nm to several tens of nm, and a quartz optical fiber probe (12) having a metal coating for light shielding around the tip is set on the back surface of the sample (11), and an excitation probe light source is provided. (13)
Irradiates the sample (11) with the excitation probe light through the quartz optical fiber probe (12). By using the quartz optical fiber probe (12), the irradiation area in the sample plane is several tens in diameter.
Since the region can be a minimum region of about nm, a more detailed evaluation of the optical response state can be performed.

[0020]

According to the present invention, as described in detail above, the region where the second excited state is generated is a region including the region where the first excited state is generated and has a wider plane range, and the state transition is performed. The spatial movement of the excited state, that is, the optical response state of the optical element can be evaluated by detecting the light emission or absorption light at this time. Further, by detecting light emission or absorption light by using time-resolved spectroscopy by irradiating pulse light, spatial movement of a light response state can be obtained as a time-resolved moving image. The spatial movement of the light response state can be obtained as a moving image of the spectral resolution by detecting the light response state by spectral analysis. be able to.

As described above, since the spatial movement process of the optical response state of the optical element to the incident signal light can be evaluated, the operation of the incident signal light and the optical element, that is, the spatial movement process of the optical response state, can be controlled. It is also possible to develop an optical element capable of performing optical information processing using only light such as control light or auxiliary light for assisting. Therefore, the optical response speed of the optical element can be increased, and the integration density can be increased. It can be densified.

[Brief description of the drawings]

FIG. 1 is a configuration showing an example of the structure of an optical property evaluation device.

FIG. 2 is a view showing a time-resolved luminescence image of a thin film sample detected in Example 1.

FIG. 3 is a configuration diagram showing a structural example of an optical property evaluation apparatus that irradiates a sample with excitation light using an optical fiber.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 optical microscope 2 light incidence mechanism 3 light incidence mechanism 4 optical filter 5 amplifying device 6 photoelectric conversion device 7 display device 8 time resolving device 9 white light incidence device 10 objective lens 11 thin film sample 12 quartz optical fiber probe 13 excitation probe light source 14 Excitation light source 15 Excitation light source

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-142151 (JP, A) JP-A-8-327537 (JP, A) JP-A-8-184552 (JP, A) JP-A-8-184552 320535 (JP, A) Ichiro Ueno, Takashi Hiraga, "Toward Sub-microsecond Organic Light Control Devices", AIST News, 1997, No. 569, pp. 1-4, Masao Saeki, Koichi Chiba, "High Rare Metals" Research Report on Fundamental Technologies for Creating New Functions by Purification (Second Phase), October 1992, Research and Development Bureau, Science and Technology Agency, pp. 275-289 (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01N 21/62-21/74 G02B 21/00 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. A micro area in a plane of a solid sample is excited by irradiating an energy beam to generate a first excited state, and the micro area includes the micro area before the first excited state disappears or attenuates. Irradiating a region having a wider planar area with light to generate a higher second excited state, and detecting light emitted when transitioning from the second excited state to the first excited state or the ground state. A method for evaluating optical properties, characterized in that: 2. A micro area in a solid plane is excited by irradiating an energy beam to generate a first excited state, and the micro area includes the micro area before the first excited state disappears or attenuates. By irradiating a region having a wider plane area with white light, a higher second excited state is generated, and light absorbed upon transition from the first excited state to the second excited state is detected. Optical property evaluation method. 3. The method for evaluating optical properties according to claim 1, wherein light emission or light absorption is spatially detected. 4. The method for evaluating optical properties according to claim 1, wherein the emitted or absorbed light is detected by using time-resolved spectroscopy by irradiating pulsed light. 5. The method for evaluating optical properties according to claim 1, wherein the emitted light or the absorbed light is detected by spectral analysis.