Optical measurement system and optical measurement method

Abstract

To perform simultaneous measurement of left circularly polarized light and right circularly polarized light of which electric field vectors rotate in the opposite directions to each other with high sensitivity and accuracy in a simple configuration.SOLUTION: An optical measurement system includes an optical system for measuring circularly polarized light and a control system for controlling the optical system. The optical system simultaneously measures left circularly polarized light and right circularly polarized light in opposite directions to each other in two spatially separated optical paths. The control system corrects the measurement results of the left circularly polarized light and the right circularly polarized light by a correction function and outputs the measurement results. The correction function compensates for the characteristic variation between the two optical paths based on a reference value measured in the two optical paths using unpolarized light.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an optical measurement system and an optical measurement method, and more particularly to optical measurement that simultaneously measures left- and right-handed circularly polarized light with high accuracy. [Background technology]

[0002] From the perspective of applications to next-generation optical information and communication technologies and bioimaging technologies, it is expected that research and development of compounds that emit circularly polarized light or circularly polarized light-emitting devices will become increasingly active in the future. Accordingly, it is expected that there will also be an increasing demand for devices or systems that can measure circularly polarized luminescence from samples in various forms, such as solutions, solids, and thin films, with high sensitivity, ease of use, and low cost.

[0003] The simplest form of circular polarization measurement involves converting circularly polarized light emitted from a sample by optical excitation or circularly polarized light emitted from a circularly polarized light-emitting device by electrical excitation into orthogonal linearly polarized light using a quarter-wave plate, and then detecting the orthogonal linearly polarized light individually as transmitted light through a polarizer by rotating the polarizer manually or with a motor. On the other hand, expensive measurement devices using a photoelastic modulator and a lock-in amplifier (such as the CPL-300 circularly polarized luminescence measurement system manufactured by JASCO Corporation) are also commercially available. These devices alternately detect left- and right-handed circularly polarized light by changing the direction of rotation of the polarizer or the polarity of the voltage applied to the photoelastic modulator. Other known configurations use a polarizing beam splitter to separate the light to be measured into left- and right-handed circularly polarized light and detect them simultaneously (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-78200 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-340833 Summary of the Invention [Problem to be solved by the invention]

[0005] In a configuration that alternately detects left-handed and right-handed circularly polarized light, the decrease and fluctuation in emission intensity over time can lead to artificial errors in the intensity difference between right-handed and left-handed circularly polarized light due to the measurement method. Therefore, simultaneous detection of right-handed and left-handed circularly polarized light is desirable. Patent Document 1 does not take into account the variations in the characteristics of the optical elements included in the optical path. Patent Document 2 uses a combination of three polarizing beam splitters to form a polarization separation unit, and compensates for the effects of the combination of polarizing beam splitters by multiplying the outputs of the two detectors by a constant so that they are the same when no sample is present. However, the method for determining the constant is not disclosed.

[0006] Patent Document 2 aims to measure circular dichroism, which detects the difference in intensity between left- and right-handed circularly polarized light absorbed by a sample, and detects light that is not absorbed by the sample and is transmitted through the sample. On the other hand, when measuring circularly polarized luminescence, the difference in intensity between left- and right-handed circularly polarized light is very small, so it is necessary to prevent excitation light from the light source from entering the detector. Therefore, the device configuration of Patent Document 2 cannot be used to measure circularly polarized luminescence. In particular, with organic samples, the ratio of left-handed and right-handed circularly polarized light contained in the circularly polarized luminescence is close to 50:50, and the difference in intensity between left-handed and right-handed circularly polarized light is very small.

[0007] The present invention aims to provide an optical measurement system and an optical measurement method that can simultaneously measure left-handed circularly polarized light and right-handed circularly polarized light, whose electric field vectors rotate in opposite directions, with high sensitivity and accuracy using a simple configuration. [Means for solving the problem]

[0008] In one embodiment, the optical measurement system includes an optical system that measures circularly polarized light and a control system that controls the optical system, The optical system simultaneously measures left-handed and right-handed circularly polarized light in opposite directions along two spatially separated optical paths, the control system corrects the measurement results of the left-handed circularly polarized light and the right-handed circularly polarized light using a correction function and outputs the corrected results; The correction function compensates for characteristic variations between the two optical paths based on reference values ​​measured in the two optical paths using unpolarized light. [Effects of the Invention]

[0009] An optical measurement system and method are realized that have a simple configuration and can simultaneously measure left-handed circularly polarized light and right-handed circularly polarized light, whose electric field vectors rotate in opposite directions, with high sensitivity and accuracy. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 10 is a diagram illustrating the necessity of simultaneous measurement of left- and right-handed circularly polarized light. [Figure 2] FIG. 10 is a diagram illustrating the necessity of simultaneous measurement of left- and right-handed circularly polarized light. [Figure 3] FIG. 1 is a schematic diagram of an optical measurement system according to an embodiment. [Figure 4] FIG. 4 is a schematic diagram of a modification of the optical measurement system of FIG. 3. [Figure 5] FIG. 10 is a diagram illustrating a method for correcting measurement data. [Figure 6] FIG. 1 is a diagram showing the chemical structure of a sample used to confirm the effect of optical measurement in an embodiment and its circularly polarized spectrum (quoted from Chem. Commun., 55, 14115 (2019)). [Figure 7] 7 is a photoluminescence (PL) spectrum of the sample in FIG. 6. [Figure 8] 1 shows spectra before and after correction of an optically isomeric Eu complex (Λ-form) measured with the optical measurement system of the embodiment. [Figure 9] 1 shows spectra before and after correction of an optically isomeric Eu complex (Δ-isomer) measured with the optical measurement system of the embodiment. [Figure 10] 1 is a flowchart of an optical measurement method. DETAILED DESCRIPTION OF THE INVENTION

[0011] Before describing the optical measurement system and the optical measurement method of the embodiment in detail, the necessity of simultaneous measurement of left and right circularly polarized light will be explained with reference to Figs. 1 and 2. Fig. 1(A) shows the light emission characteristics of an organic light emitting diode (OLED), a sample fabricated by the inventors. The horizontal axis is time (ms) and the vertical axis is luminance (Cd / m 2 ) The sample has a simple structure in which an organic light-emitting layer is placed between two electrodes, and a hole injection layer is inserted between the organic light-emitting layer and the anode. The organic light-emitting layer uses chiral BPP with the structure shown in Figure 1(B), namely (R,R)-BPP and its enantiomer, (S,S)-BPP.

[0012] The cross marks in Figure 1 are data points, and the dashed line is a fitting line. L ) and the intensity of right-handed circularly polarized light (I R ) are measured alternately, the intensity obtained gradually decreases due to the deterioration of the emission over time. If there is a time difference between the measurements of right-handed and left-handed circularly polarized light when the emission intensity is deteriorating, the intensity difference cannot be calculated correctly.

[0013] Figure 2 (A) is an illustration of the measurement of left- and right-circularly polarized light from a uniform solution sample, and (B) is an illustration of the measurement of left- and right-circularly polarized light from the fabricated thin-film device. The solid line shows the intensity of left-circularly polarized light, and the dashed line shows the intensity of right-circularly polarized light. The dotted line is the sinusoidal signal applied to the photoelastic modulator. For a uniform solution sample, even if there is a time lag between the measurements of left- and right-circularly polarized light, the polarization intensity of the object being measured remains relatively constant, and the intensity difference is also stable. However, the intensity of circularly polarized light emitted from an organic thin-film device fluctuates greatly, deviating significantly from the average value. Even with high-speed measurements, the time lag between measurements increases the variability in the intensity difference between left- and right-circularly polarized light, resulting in measurement errors.

[0014] In this embodiment, we propose an optical measurement technology that can simultaneously and accurately measure left-handed and right-handed circularly polarized light from weak light emission with high sensitivity. To achieve this, the left-handed and right-handed circularly polarized light contained in the circularly polarized light emission from a sample are spatially separated, and the left-handed and right-handed circularly polarized light measurement results are simultaneously measured and output after being corrected using a correction function. The correction function is determined based on reference values ​​measured in advance using two spatially separated optical paths using unpolarized light, and compensates for characteristic variations between the two optical paths. In the following description, identical components are assigned the same reference numerals, and redundant explanations may be omitted.

[0015] <Optical measurement system> 3 is a schematic diagram of an optical measurement system 1A according to an embodiment. The optical measurement system 1A includes an optical system 10A and a control system 20A. The optical system 10A includes a quarter-wave plate 12, a polarizing beam splitter 13, a first multichannel spectrometer 19-1 disposed on one output port side of the polarizing beam splitter 13, and a second multichannel spectrometer 19-2 disposed on the other output port side of the polarizing beam splitter 13. The first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2 are examples of detection devices that detect left-handed and right-handed circularly polarized light, respectively, which are opposite in direction to each other.

[0016] At least one of a first polarizer 15 and a first lens 17 may be inserted between the polarizing beam splitter 13 and the first multichannel spectrometer 19-1. At least one of a second polarizer 16 and a second lens 18 may be inserted between the polarizing beam splitter 13 and the second multichannel spectrometer 19-2. The use of the first polarizer 15 and the second polarizer 16 can eliminate the influence of the other circularly polarized light that has entered as stray light and increase the purity of each spatially separated polarized light. The first lens 17 and the second lens 18 are optical elements such as an objective lens and a condenser lens, and efficiently guide the separated polarized light to the corresponding first multichannel spectrometer 19-1 and second multichannel spectrometer 19-2.

[0017] When a voltage is applied to sample 30A placed on sample stage 11, circularly polarized light is obtained. Sample 30A is, for example, an organic thin-film device with the same configuration as the OLED used in the luminance measurement in Figure 1. The circularly polarized light from sample 30A contains left-handed circularly polarized light CPL1 and right-handed circularly polarized light CPL2. Left-handed circularly polarized light CPL1 and right-handed circularly polarized light CPL2 are each given a phase rotation of π / 2 by passing through quarter-wave plate 12, and are converted into linearly polarized light LPL1 and LPL2. A mica plate may be used as quarter-wave plate 12. The mica plate can be rotated 360°, allowing the optical axis to be aligned with a simple operation without rotating sample 30A.

[0018] The polarizing beam splitter 13 spatially separates linearly polarized light LPL1 and LPL2, whose polarization planes are orthogonal to each other. The polarizing beam splitter 13 reflects, for example, vertically polarized S-waves (SPL) and transmits horizontally polarized P-waves (PPL). The P-waves transmitted through the polarizing beam splitter 13 have their polarization purity increased by the first polarizer 15, are focused by the first lens 17, and enter the first multichannel spectrometer 19-1. The S-waves reflected by the polarizing beam splitter 13 have their polarization purity increased by the second polarizer 16, are focused by the second lens 18, and enter the second multichannel spectrometer 19-2.

[0019] Generally, in the case of circularly polarized light emitted from an organic thin film sample, the difference in intensity between left-handed and right-handed circularly polarized light is small. To detect even small intensity differences, it is desirable to minimize light loss in the optical components and accurately align the optical axis of the polarized light. For this reason, the optical system 10A uses a single polarizing beam splitter 13 to suppress light loss. Using a single polarizing beam splitter 13 is also advantageous in that it suppresses the accumulation of variations in transmission and reflection characteristics. An automatic rotation stage may be incorporated into each of the quarter-wave plate 12, first polarizer 15, and second polarizer 16. By incorporating an automatic rotation stage, the optical axis of the polarized light can be aligned with an accuracy of 0.005°.

[0020] The first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2 are synchronously controlled by a control system 20A to simultaneously detect left-handed and right-handed circularly polarized components over a predetermined wavelength range. The exposure time, number of averaging operations, number of consecutive measurements, etc. of the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2 can be set appropriately.

[0021] The control system 20A includes a voltmeter 21, a function generator 22, and an information processing device 23. The information processing device 23 is a personal computer (PC), a smartphone, a tablet terminal, etc. The information processing device 23 is connected to the voltmeter 21 and the function generator 22 by cable or wirelessly, and controls the operations of the voltmeter 21 and the function generator 22.

[0022] The voltmeter 21 is, for example, a digital voltmeter with a DC voltage and current generation function. The voltmeter 21 applies a predetermined constant voltage to the sample 30A and reads out the current value. The applied voltage causes electroluminescence to be obtained from the sample 30A. When the function generator 22 receives a spectroscopic measurement trigger command from the information processing device 23, it generates a simultaneous detection trigger signal and transmits it to the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2. The trigger signal is, for example, a 4.0 V, 2 microsecond multichannel synchronization pulse signal.

[0023] The first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2 each measure the received light intensity of the corresponding circularly polarized light component at multiple wavelengths in synchronization with a synchronization pulse signal from a function generator 22. The measurement results are sent to an information processing device 23. As will be described later, the information processing device 23 corrects the measurement data using a correction function α(λ) in consideration of the reflectance and transmittance of the polarizing beam splitter 13 and the device characteristics of the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2.

[0024] FIG. 4 is a schematic diagram of an optical measurement system 1B as a variation of the system of FIG. 3. The optical measurement system 1B includes an optical system 10B and a control system 20B. The optical system 10B includes a quarter-wave plate 12, a polarizing beam splitter 13, a first multichannel spectrometer 19-1, a second multichannel spectrometer 19-2, and a light source 14. As with the optical system 10A of FIG. 3, at least one of a first polarizer 15 and a first lens 17 may be inserted between the polarizing beam splitter 13 and the first multichannel spectrometer 19-1. At least one of a second polarizer 16 and a second lens 18 may be inserted between the polarizing beam splitter 13 and the second multichannel spectrometer 19-2. An automatic rotation stage may be incorporated into each of the quarter-wave plate 12, the first polarizer 15, and the second polarizer 16 to align the optical axes of the polarized light with high precision.

[0025] Light source 14 is a light source for exciting sample 30B. Sample 30B is, for example, an organic thin film or solution sample, and is optically excited by light source 14 to emit circularly polarized light. Using light source 14, it is possible to measure the PL spectrum of sample 30B. When (R,R)-BPP and (S,S)-BPP are used in the organic light-emitting layer of sample 30B, the excitation wavelength of light source 14 is 500 nm, which is the maximum absorption wavelength of BPP. A filter corresponding to the excitation wavelength may be inserted at a position that does not affect the circularly polarized light emission to suppress the influence of the excitation light on the measurement optical system.

[0026] The control system 20B includes a function generator 22 and an information processing device 23. The information processing device 23 may be connected to the light source 14 to control the output timing of the excitation light and the light source power. The information processing device 23 is also connected to the function generator 22 and outputs a command to the function generator 22 to generate and output a trigger signal for multi-channel simultaneous detection.

[0027] The first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2 simultaneously detect the intensities of the corresponding circularly polarized light components at the timing of a trigger signal from the function generator 22. The detection results are sent to an information processing device 23. The information processing device 23 corrects the measurement data using a correction function α(λ) in consideration of the reflectance and transmittance of the polarizing beam splitter 13 and the device characteristics of the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2.

[0028] <Measurement data correction> FIG. 5 shows a method for correcting measurement data. Consider a configuration for measuring the circularly polarized spectrum from a sample 30. The intensity of left-handed circularly polarized light at wavelength λ contained in the circularly polarized light emitted from the sample 30 is expressed as I L (λ), the intensity of right-handed circularly polarized light is I R Let (λ).

[0029] The transmittance of the polarizing beam splitter 13 at wavelength λ is T(λ), and the reflectance is R(λ). The instrument function of the first multichannel spectrometer 19-1 is f(λ), and the instrument function of the second multichannel spectrometer 19-2 is h(λ). The measured value obtained by the first multichannel spectrometer 19-1 is I'. L (λ), the measured value obtained by the second multichannel spectrometer 19-2 is I' R Let (λ).

[0030] Measured value I' L (λ) is the true intensity of left-handed circularly polarized light I L (λ) is not necessarily the same as the measured value I'. R (λ) is also the true intensity of right-handed circularly polarized light, I R (λ). Furthermore, the actual measured value I' L (λ) true intensity I L Deviation from (λ) and measured value I' R (λ) true intensity I RThe deviation from (λ) is not necessarily the same because there are variations in the characteristics of the detector arrays used in the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2 and wavelength-dependent differences in the transmittance and reflectance of the polarizing beam splitter 13.

[0031] The relationship between the measured value I'(λ) at wavelength λ and the true intensity I(λ) is expressed by equations (1) and (2) using the transmission and reflection characteristics of the polarizing beam splitter 13 and the device characteristics.

[0032]

number

[0033] In order to correct the measured data, the measured value of unpolarized light is used as a reference. That is, instead of the sample 30 that emits circularly polarized light, an unpolarized light source is installed, and the two lights separated by the polarizing beam splitter 13 are detected by the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2. If the intensity of the unpolarized light source at wavelength λ is I0(λ), ideally, the intensity I of the light component incident on the first multichannel spectrometer 19-1 should be L0 (λ) and the intensity I of the light component incident on the second multichannel spectrometer 19-2. R0 (λ) is equal to (I L0 (λ)=I R0 (λ)).

[0034] The measured values ​​at wavelength λ when using an unpolarized light source are I' L0 (λ) and I' R0 (λ) The measured value of unpolarized light is I' L0 (λ) and true intensity I L0 (λ) relationship and actual measured value I' R0(λ) and true intensity I R0 The relationship of (λ) is expressed by equations (3) and (4).

[0035]

number

[0036]

number

[0037] In the case of unpolarized light, ideally, the ratio of the measured values ​​of the two split lights, i.e., α(λ), should be 1. Any deviation from the ratio of 1 reflects the reflectance and transmittance of the polarizing beam splitter 13 and the instrument functions of the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2. A correction function α(λ) is determined to compensate for the deviation from the ratio of 1.

[0038] In the case of organic samples, the intensity ratio of left-handed and right-handed circularly polarized light is slightly different from 50:50, but the difference in intensity is very small. The g value, which is a factor that represents the asymmetry between left-handed and right-handed circularly polarized light, i.e., the polarization of circularly polarized light, is g=2×(I L (λ)-I R (λ)) / (I L (λ)+I R (λ) Substituting equations (1) and (2) for the g value and using equation (5) gives equation (6).

[0039]

number

[0040] <Effectiveness check> Figure 6 shows a standard europium (Eu) complex (A) used to confirm the effectiveness of the optical measurements of this embodiment, and its circularly polarized spectrum (B). The source is Chem. Commun., 55, 14115 (2019). The Eu complex has enantiomers: a left-handed helical structure (Λ) and a right-handed helical structure (Δ). As shown in Figure 6 (B), the circularly polarized spectrum of the left-handed helical structure and the circularly polarized spectrum of the right-handed helical structure are nearly symmetrical with respect to the zero-intensity line.

[0041] Using the solution sample of the standard substance shown in Figure 6, the circularly polarized spectrum was measured using the optical measurement system 1B of the embodiment. A solution sample was prepared by dissolving 18 μM of the Eu complex shown in Figure 6 in an MeOH-MeCN solution. A 405 nm laser was used as the excitation light source 14, outputting at a power of 80 mW. The exposure time was 30 ms, and the number of integrations was 7,200.

[0042] Figure 7 shows the PL spectra measured by the optical measurement system 1B. The horizontal axis represents wavelength, and the vertical axis represents the average of the measured values ​​of left-handed and right-handed circularly polarized light detected by the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2, corrected with the correction function α(λ). Over the wavelength range of 580 to 720 nm, the right-handed and left-handed helical structures produce nearly identical spectra. The shape of this PL spectrum is in good agreement with a previously reported spectrum (Chem. Commun., 55, 14115 (2019)).

[0043] Figure 8 shows the spectra of the left-handed helical structure (Λ) measured with the optical measurement system 1B before and after correction. Figure 8 (A) shows the spectrum near the peak wavelength before correction with the correction function α(λ), and (B) shows the spectrum near the peak wavelength after correction.

[0044] Before correction using α(λ), there is a difference in the wavelength dependence of the peak waveforms of the spectrum of left-handed circularly polarized light (solid line) and the spectrum of right-handed circularly polarized light (dashed line) across the entire wavelength range from 580 to 720 nm. This is thought to be due to differences in the transmittance and reflectance of the polarizing beam splitter 13 and the device characteristics of the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2.

[0045] By correcting with a correction function α(λ) determined in advance using an unpolarized light source, the peak wavelengths of left-handed and right-handed circularly polarized light coincide over the entire range of measured wavelengths, allowing the intensity difference at the peak wavelength to be accurately determined.

[0046] Figure 9 shows the spectra of the right-handed helical structure (Δ) measured with the optical measurement system 1B before and after correction. Figure 9 (A) shows the spectrum near the peak wavelength before correction with the correction function α(λ), and (B) shows the spectrum near the peak wavelength after correction.

[0047] Before correction with α(λ), there is a difference in the wavelength dependence of the peak waveforms of the spectrum of left-handed circularly polarized light (solid line) and the spectrum of right-handed circularly polarized light (dashed line) over the entire wavelength range from 580 to 720 nm.

[0048] By correcting the obtained measurement values ​​with the correction function α(λ), the peak wavelengths of left-handed and right-handed circularly polarized light coincide over the entire range of measured wavelengths, and the intensity difference at the peak wavelength can be accurately determined.

[0049] 10 is a flowchart of an optical measurement method according to an embodiment. Using an unpolarized light source, a correction function α(λ) is determined (S11) to compensate for variations in the emission intensity characteristics of two spatially separated optical paths. In the example of the optical system 10 described above, these are the optical path that passes through the polarizing beam splitter 13 and is received by the first multichannel spectrometer 19-1, and the optical path that is reflected by the polarizing beam splitter 13 and is received by the second multichannel spectrometer 19-2. The correction function α(λ) compensates for, for example, the transmittance and reflectance of the polarizing beam splitter 13 and the instrument functions (detection sensitivity, etc.) of the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2.

[0050] A sample is placed in optical system 10 (10A or 10B), and the emission intensities of the left-handed and right-handed circularly polarized light components are measured simultaneously along two optical paths (S12). Next, information processing device 23 corrects the measured values ​​using correction function α(λ) (S13), and outputs the corrected measured values ​​(S14). This measurement method allows for simultaneous measurement of left-handed and right-handed circularly polarized light with high sensitivity and accuracy using a simple system configuration.

[0051] In the optical measurement system 1A or 1B of the embodiment, it is possible to monitor the change over time in the light emission from the sample 30 while measuring the circularly polarized light. Generally, it is difficult to measure circularly polarized light from samples or devices that have weak emission intensity and rapid attenuation. However, in the embodiment, left- and right-handed circularly polarized light are detected simultaneously by the first multichannel spectrometer 19-1 and the second multichannel spectrometer 19-2, making it possible to accurately measure left-handed and right-handed circularly polarized light with high sensitivity without being affected by time fluctuations. By monitoring the change over time in the light emission from the sample 30, it is also possible to simultaneously measure the deterioration state of the sample 30 before and after measurement.

[0052] Conventional methods using a rotating linear polarizer or commercially available measurement devices using a photoelastic modulator require measurement times ranging from several tens of minutes to an hour. In contrast, the optical measurement system 1A or 1B of the embodiment can accurately measure circular polarization over a wide wavelength range in a measurement time ranging from several tens of seconds to several tens of minutes. The system configuration is extremely simple, and costs can be reduced to less than one-fifth of those of commercially available circular polarization measurement devices.

[0053] It is also possible to measure the time change in luminescence intensity and luminescence accompanying chemical reactions, which were difficult to measure using conventional circular polarization measurement methods. Furthermore, by using a polarizing beam splitter and detector array with sensitivity in the near-infrared region, high-precision circular polarization measurement in the near-infrared region becomes possible, which is expected to be applied to bioimaging.

[0054] Although a multichannel spectrometer is used as the detection device in the embodiment, the optical measurement technique of the present invention can also be applied to a measurement system using a wavelength-sweeping detector. In this case, too, the variation in the device characteristics between the two detectors can be estimated in advance using an unpolarized light source, and a correction function can be obtained. [Explanation of symbols]

[0055] 1A, 1B Optical Measurement System 10, 10A, 10B optical system 13 Polarizing beam splitter 14 Light source 15 First polarizer 16 Second polarizer 17 First lens 18 Second lens 19-1 First multi-channel spectrometer (first detection device) 19-2 Second multichannel spectrometer (second detection device) 20A, 20B control system 21 Voltmeter 22 Function Generator 23 Information processing equipment

Claims

1. an optical system for measuring circularly polarized light; a control system for controlling the optical system; Equipped with the optical system includes a polarizing beam splitter that separates light containing left-handed circularly polarized light and right-handed circularly polarized light in opposite directions into light containing the left-handed circularly polarized light component and light containing the right-handed circularly polarized light component and inputs the separated light into two spatially separated optical paths, a first detection device that detects the left-handed circularly polarized light component at one output side of the polarizing beam splitter corresponding to one of the two optical paths, and a second detection device that detects the right-handed circularly polarized light component at the other output side of the polarizing beam splitter corresponding to the other of the two optical paths, and the left-handed circularly polarized light and the right-handed circularly polarized light are simultaneously measured by the first detection device and the second detection device; the control system corrects the measurement results of the left-handed circularly polarized light and the right-handed circularly polarized light using a correction function and outputs the corrected results; the correction function compensates for differences in wavelength dependencies of transmittance and reflectance of the polarizing beam splitter and characteristic variations between the two optical paths, including characteristic variations between the first detection device and the second detection device, based on actual measurement values ​​obtained by inputting unpolarized light to the polarizing beam splitter and measuring the intensities of light emitted from the two optical paths by the first detection device and the second detection device. Optical measurement system.

2. the first detection device is a first multi-channel spectrometer that detects a spectrum of the left-handed circularly polarized light at multiple wavelengths; the second detection device is a second multi-channel spectrometer that detects a spectrum of the right-handed circularly polarized light at the multiple wavelengths; the correction function compensates for variations in device characteristics of the first multichannel spectrometer and the second multichannel spectrometer; The optical measurement system of claim 1 .

3. the control system includes an information processing device and a function generator connected to the information processing device; the information processing device outputs a command signal to the function generator to cause the first detection device and the second detection device to perform simultaneous measurements; the function generator outputs a trigger signal for starting measurement to the first detection device and the second detection device in accordance with the command signal; 3. An optical measurement system according to claim 1 or 2.

4. The optical system comprises: a quarter-wave plate disposed between the sample and the polarizing beam splitter; a first polarizer disposed between the polarizing beam splitter and the first detection device; a second polarizer disposed between the polarizing beam splitter and the second detection device; The optical measurement system of claim 1 , further comprising:

5. the control system includes a voltmeter that applies a voltage to the sample; the first detection device detects the left-handed circularly polarized light contained in the electroluminescence from the sample, and the second detection device detects the right-handed circularly polarized light contained in the electroluminescence.

5. The optical measurement system of claim 4.

6. the optical system further includes a light source that optically excites the sample; the first detection device detects the left-handed circularly polarized light contained in the photoluminescence from the sample, and the second detection device detects the right-handed circularly polarized light contained in the photoluminescence.

5. The optical measurement system of claim 4.

7. An optical measurement method using the optical measurement system according to any one of claims 1 to 6, comprising: determining the correction function that compensates for the characteristic variations of the two optical paths based on the actual measurement values; a sample is placed in the optical system, and the left-handed circularly polarized light and the right-handed circularly polarized light contained in the circularly polarized light emitted from the sample are measured along the two optical paths; an information processing device correcting the measured value of at least one of the left-handed circularly polarized light and the right-handed circularly polarized light using the correction function and outputting the corrected measured value; Optical measurement method.

8. detecting the left-handed circularly polarized component at one output side of the polarizing beam splitter and detecting the right-handed circularly polarized component at the other output side of the polarizing beam splitter; correcting at least one of the detected left-handed circularly polarized light component and the detected right-handed circularly polarized light component using a correction function that compensates for differences in wavelength dependence of transmittance and reflectance of the polarizing beam splitter and characteristic variations between the first detection device and the second detection device; The optical measurement method according to claim 7.

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