KR101504061B1 - System for measuring light absorption coefficient of sample and measuring method thereof - Google Patents

Abstract

The present invention relates to a system for measuring a light absorption coefficient of a sample and a measuring method using the same. The system includes: a laser beam source configured to irradiate a laser beam; a retroreflector configured to reflect a laser beam; a polarization beam splitter provided such that a sample can be disposed between the polarization beam splitter and the polarization beam splitter, having a polarization beam splitter coating layer that splits a laser beam incident from the laser beam source into a reference beam and a probe beam by reflecting and transmitting the laser beam, and having a reflective coating layer that reflects the reference beam and the probe beam such that the reference beam and the probe beam can pass through the sample by being reflected from the retroreflector; a heating laser irradiating unit configured to irradiate a heating laser beam to the probe beam to apply a change in the refractive index of the sample to the probe beam; a variable retarder configured to change a polarization state of the reference beam and the probe beam that are coupled to each other by passing through the polarization beam splitter; a polarization mixer configured to split the reference beam and the probe beam that pass through the variable retarder, and to rotate a polarization surface of the reference beam and the probe beam at a predetermined angle with respect to a path direction; and a first light receiving device and a second light receiving device configured to respectively receive the reference beam and the probe beam irradiated from the polarization mixer and to convert the reference beam and the probe beam into electrical signals. Therefore, a light absorption coefficient of a sample such as atmospheric aerosol may be easily measured, and the accuracy of such a measured light absorption coefficient value may be improved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light absorption coefficient measurement system,

The present invention relates to a system and method for measuring the optical absorption coefficient of a sample, and more particularly, to a system and method for measuring a light absorption coefficient of a sample, and more particularly, to a method of measuring a light absorption coefficient of a sample such as an atmospheric aerosol, And more particularly to a system and method for measuring the optical absorption coefficient of a sample.

Generally, atmospheric aerosols are related to air quality, weather, and climate. They scatter the light to cool the atmosphere, absorb the light to warm it, directly affect the climate change, and act as cloud condensation nuclei and ice nuclei, , Cloud reflectance and rainfall indirectly. In addition, the optical absorption coefficient of aerosols in these atmospheres is used as a data for judging global warming, and it is required to accurately measure the optical absorption coefficient using aerosol as a sample.

As a conventional technique for measuring the characteristics of light absorption, Korean Patent Laid-Open No. 10-2006-0050572 discloses a " method and apparatus for measuring light absorption characteristics of a sample " ) And a light exiting surface (s), and a reflecting surface on which a sample to be measured is reflected by the total reflection on the sample through the light is transmitted, and light emitted from the light source through the light exiting surface Wherein the light is transmitted to the light incidence surface of the optical waveguide so that the light enters the optical waveguide at least once again and receives light again from the optical waveguide, And detecting the characteristic.

However, the prior art has a problem that it is difficult to apply to the measurement of the light absorption coefficient for atmospheric aerosol.

In order to solve the problems of the prior art as described above, the present invention aims to easily measure the light absorption coefficient of a sample such as an atmospheric aerosol, and to increase the accuracy of the measured value of the light absorption coefficient have. Other objects of the present invention will become readily apparent from the following description of the embodiments.

According to an aspect of the present invention, there is provided a system for measuring a light absorption coefficient using an aerosol as a sample, comprising: a laser light source for irradiating a laser; A retroreflector for reflecting the beam; A polarizing beam splitter coating layer which is provided so as to position a sample between the reference beam and the retro-reflector and is divided into a reference beam and a probe beam by reflecting and transmitting a laser beam from the laser beam source, A polarizing beam splitter in which a reflective coating layer is formed which reflects the beam as it is reflected by the retroreflector to pass through the sample; A heating laser irradiation unit for irradiating the probe beam with a heating laser to change the refractive index of the sample; A polarization beam splitter that changes the polarization state of the reference beam and the probe beam that are combined through the polarization beam splitter; A polarization mixer that splits the reference beam and the probe beam passed through the barrier bladder and rotates the polarization plane of the reference beam and the probe beam at a predetermined angle around the path direction; And a first and a second light receiving element for receiving the reference beam and the probe beam emitted from the polarization mixer, respectively, and converting the received reference beam and the probe beam into an electrical signal.

The polarizing beam splitter has a polarizing beam splitter coating layer partially formed on the front surface so that the laser beam is obliquely irradiated. A reference beam reflected by the polarizing beam splitter coating layer is reflected by the retro-reflector and is incident on the front surface, So that the reference beam incident on the front surface is reflected on the rear surface of the reflective coating layer and the rear surface of the polarizing beam splitter coating layer so as to be transmitted to the outside, and the probe beam, transmitted through the polarizing beam splitter coating layer, And the retroreflector so as to be incident on the polarizing beam splitter coating layer so as to pass through the sample, and the probe beam incident on the polarizing beam splitter coating layer may be combined with the reference beam transmitted to the outside to be transmitted to the outside .

The heating laser irradiation unit may irradiate the heating laser to a position where the probe beam reflected by the retro-reflector is incident on the polarization beam splitter coating layer.

Wherein the heating laser irradiation unit comprises: a heating laser light source for irradiating the heating laser; And a reflecting member for reflecting the heating laser emitted from the heating laser light source so as to cross the probe beam.

Wherein the barrier rib tether has a voltage value output by irradiation of the reference beam and the probe beam from the first and second light receiving elements in a state in which no sample is present and in a state in which the heating laser is not irradiated from the heating laser irradiation unit So that the polarization state of the reference beam and the probe beam can be adjusted.

And a sample accommodating portion which is provided between the polarizing beam splitter and the retro reflector and is made of a light transmissive material and has a supply port and an outlet port for allowing the aerosol to pass therethrough.

According to another aspect of the present invention, there is provided a method for measuring a light absorption coefficient using an aerosol as a sample, comprising the steps of: irradiating a laser beam obliquely onto a polarizing beam splitter coating layer formed on a front surface of a polarizing beam splitter, Beam so that the reference beam and the probe beam are reflected by a retro-reflector and a reflection coating layer formed on the back surface of the polarizing beam splitter so as to pass through the region where the sample is located; The reference beam and the probe beam passing through the polarizing beam splitter and passing through the polarizing mixer so that each of the polarizing planes is rotated at a predetermined angle around the path direction and the probe beam, 1 and the second light receiving element, respectively; The polarized state of the reference beam and the probe beam is adjusted by the barrier bladder disposed on the front end of the polarization mixer without placing the sample in the area, so that the voltage value output from each of the first and second light- Setting the same; Changing a refractive index of the probe beam by irradiating the probe beam with a heating laser while the sample is positioned in the region; And reading a difference between voltage values output from the first and second light receiving elements by irradiation of the reference beam and the probe beam, respectively.

Wherein the step of dividing and reflecting the laser beam by a polarizing beam splitter into a reference beam and a probe beam comprises: irradiating the laser beam obliquely onto the polarizing beam splitter coating layer partially formed on the front surface of the polarizing beam splitter; Wherein the reference beam reflected by the retroreflector is incident on the front surface of the retroreflector so that the reference beam is incident on the front surface of the retroreflector and the reference beam incident on the front surface is partially formed on the rear surface of the polarizing beam splitter coating layer, So that the probe beam transmitted through the polarizing beam splitter coating layer is reflected by the reflective coating layer and the retro reflector and is incident on the polarizing beam splitter coating layer to pass through the sample, Polarized beam spline The probe beam incident on the turntable layer may be combined with the reference beam transmitted to the outside and transmitted to the outside.

The step of changing the refractive index of the probe beam may irradiate the heating laser at a position where the probe beam reflected from the retro-reflector enters the polarization beam splitter coating layer.

The step of varying the refractive index of the probe beam may irradiate the heating laser to cross the probe beam.

Further comprising the step of calculating a light absorption coefficient by reading a difference between voltage values output by the first and second light receiving elements, wherein the step of calculating the light absorption coefficient comprises the steps of: The difference between the voltage values of the first and second light receiving elements obtained for a specific material is read as a reference value and the difference between the voltage values of the first and second light receiving elements obtained for the sample is calibrated to the reference value, The coefficient can be calculated.

According to the system and method for measuring the optical absorption coefficient of a sample according to the present invention, the optical absorption coefficient of a sample such as an atmospheric aerosol can be easily measured, and the accuracy of the measured value of the optical absorption coefficient can be increased.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram showing a light absorption coefficient measurement system of a sample according to a first embodiment of the present invention; FIG.
2 is a configuration diagram showing a light absorption coefficient measurement system of a sample according to a second embodiment of the present invention.
3 is a flow chart showing a method of measuring a light absorption coefficient of a sample according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in detail in the drawings. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but is to be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention, And the scope of the present invention is not limited to the following examples.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant explanations thereof will be omitted.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram showing a light absorption coefficient measurement system of a sample according to a first embodiment of the present invention; FIG.

Referring to FIG. 1, a system 100 for measuring the optical absorption coefficient of a sample according to the first embodiment of the present invention is a system for measuring a light absorption coefficient using an aerosol as a sample. The system includes a laser light source 110, a retroreflector a retroreflector 120, a polarized beam-splitter 130, a heating laser irradiation unit 140, a variable retarder 150, a polarization mixer 160, Devices 170,180.

The laser light source 110 irradiates the laser toward the polarization beam splitter 130. For example, a light source for irradiating a 632 nm He-Ne laser may be used.

The retro-reflector 120 is provided to reflect the beam. The retro-reflector 120 may be disposed on the opposite side of the polarizing beam splitter 130 with a sample interposed therebetween. The retro-reflector 120 may have a reflecting surface of 90 degrees to reflect the beam in the opposite direction . On the other hand, the sample may be an aerosol collectively referred to as a solid or liquid particulate matter floating in the air, and may be collected through a collecting device such as a filter in the air.

The polarization beam splitter 130 is installed so that the sample is positioned between the reference beam and the retro beam reflector 120. The reference beam and the probe beam are reflected and transmitted through the laser beam from the laser beam source 110, The reference beam and the probe beam are reflected by the retroreflector 120 to form a reflection coating layer 132 that reflects the reference beam and the probe beam to pass through the sample.

The polarizing beam splitter 130 allows the laser beam to be obliquely irradiated onto the polarizing beam splitter coating layer 131 partially formed on the front surface 133 and allows the reference beam reflected by the polarizing beam splitter coating layer 131 to be reflected by the retro- The reference beam incident on the front surface 133 is reflected on the back surface of the reflective coating layer 132 and the rear surface of the polarizing beam splitter coating layer 131 to be transmitted to the outside The probe beam transmitted through the polarizing beam splitter coating layer 131 is reflected by the reflective coating layer 132 and the retro reflector 120 and is incident on the polarizing beam splitter coating layer 131 to pass through the sample, The probe beam incident on the reference beam 131 is combined with the reference beam transmitted to the outside and transmitted to the outside.

The polarizing beam splitter coating layer 131 may be formed by coating a material for polarizing the laser, such as a material including inconel or chrome having a dielectric and partial light transmission The splitting ratio can be set to 10:90, 30:70, 50:50, and the like according to the characteristics of the coating. By polarizing the laser of the laser light source 110, a reference beam (for example, s-polarized light) And a probe beam that is a p-polarized light. Here, on the contrary, the reference beam may be p-polarized, and the probe beam may be s-polarized. In addition, the polarizing beam splitter coating layer 131 has a reflecting surface at the rear side.

The reflective coating layer 132 may be formed by coating a material that reflects light on the opposite side of the polarizing beam splitter coating layer 131 in the polarizing beam splitter 130 and may be formed by a polarizing beam splitter 130, And may be formed at a position deviated from the beam splitter coating layer 131.

The heating laser irradiation unit 140 irradiates a heating laser to change the refractive index of the sample to the probe beam. For example, as in the present embodiment, a probe beam reflected from the retro-reflector 120 in the polarizing beam splitter coating layer 131 is incident And it has an advantage of heating the whole of the probe beam as in the present embodiment by irradiation with a heating laser, thereby increasing the measurement volume. The heating laser irradiation unit 140 may be a heating laser having a power of 0.8 to 1.2 W, for example, an output of 1 W, for example, a diode pumped solid state (DPSS) laser, For confirmation, a laser with a wavelength of 532 nm can be used, and as another example, an infrared laser can be used to confirm absorption in the infrared region. Even if the specimen passes through the reference beam and the probe beam, there is no change. When the probe beam is irradiated with a high-power heating laser for changing the refractive index, the aerosol around the probe beam absorbs the heating laser beam and the periphery of the probe beam is heated This causes the refractive index around the probe beam to change, so that the optical path of the probe beam changes very finely. Therefore, the probe beam causes a difference in light path from the reference beam, and the first and second light receiving elements 170 and 180 can read the change. At this time, if the aerosol absorbs light, the difference in the output voltage values of the first and second light receiving elements 170 and 180 further increases. If the aerosol does not absorb the light, the first and second light receiving elements 170 and 180 there is no difference in output voltage value or its change in a state where the output voltage is locked.

The barrierbattery 150 passes through the polarization beam splitter 130 to change the polarization state of the combined reference beam and probe beam. The barrier rib detacher 150 outputs output from the first and second light receiving elements 170 and 180 by irradiation of the reference beam and the probe beam, respectively, in a state in which no sample is present and a heating laser is not irradiated from the heating laser irradiation unit 140 So that the polarization state of the reference beam and the probe beam can be adjusted.

For example, a liquid crystal variable retarder may be used, and the birefringence retarder 150 may change birefringence or light delay by varying the molecular arrangement of the liquid crystal in accordance with the applied voltage, for example, the voltage magnitude of 1 to 12 V. The polarized state of the combined reference beam and the probe beam can be changed by changing the molecular arrangement of the liquid crystal so that the amount of light received by the first and second light receiving elements 170 and 180 can be changed. The barrier rib detacher 150 does not irradiate the heating laser from the laser irradiating unit 190 in the absence of the sample and then sets the output voltage values of the first and second light receiving elements 170 and 180 to the same value ), So that the change in the optical path difference between the reference beam and the probe beam of the interferometer can be read most easily. That is, when the output voltages of the first and second light receiving elements 170 and 180 are set to the same value, even if the difference in optical path between the reference beam and the probe beam is extremely small, a change in the measured values of the first and second light receiving elements 170 and 180 However, when the output voltages of the first and second light receiving elements 170 and 180 are different, no matter how much the difference in optical path between the reference beam and the probe beam increases, the measured values of the first and second light receiving elements 170 and 180 are changed It is not.

The polarization mixer 160 divides the reference beam and the probe beam that have passed through the barrier bladder 150 and allows the polarization plane of the reference beam and the probe beam to rotate at a certain angle around the path direction. The polarized light mixer 160 is a type of beam splitter that divides the reference beam and the probe beam that are combined together and is irradiated onto the first and second light receiving elements 170 and 180. The polarization plane of the divided reference beam and the probe beam is The first and second light receiving elements 170 and 180 generate the output voltage corresponding to the optical path change with respect to the phase difference by rotating the path direction at a predetermined angle, for example, 45 degrees. At this time, the reference beam and the probe beam received by the first and second light receiving elements 170 and 180, respectively, can be 90 degrees in polarization plane even if the polarization plane is rotated by the polarization mixer 160.

The first and second light receiving elements 170 and 180 receive the reference beam and the probe beam emitted from the polarization mixer 160, respectively, and convert them into electrical signals. Also, a photo diode may be used as the first and second light receiving elements 170 and 180, for example.

In order to read the output voltages of the first and second light receiving elements 170 and 180, a calculator 300 may be provided. Here, the calculation unit 300 receives the voltages output from the first and second light-receiving elements 170 and 180, and calculates the difference between the output voltages of the first and second light-receiving elements 170 and 180 as the aerosol absorbs light . For example, when the aerosol as the sample absorbs light, the difference between the first and second light receiving elements 170 and 180 largely occurs. When the light absorption is reduced, the difference between the first and second light receiving elements 170 and 180 is small By reading the difference between the first and second light receiving elements 170 and 180, the light absorption of the aerosol as a sample can be measured. For example, since a light absorption coefficient for a specific concentration is known in a substance such as carbon dioxide (CO ₂ ), when the difference between the first and second light receiving elements 170 and 180 is measured when carbon dioxide having a specific concentration is injected into the sample, the voltage may be the light absorption coefficient. Specifically, for example, if it is known that a light absorption coefficient of 10 ppm carbon dioxide is 100, when 10 ppm of carbon dioxide is injected into a sample aerosol, the output voltage difference between the first and second light receiving elements 170 and 180 is measured as 10 V , It becomes possible to calibrate 10 V to a light absorption coefficient of 100. Therefore, when a specific aerosol is injected, if the output voltage difference between the first and second light receiving elements 170 and 180 is 3V, the light absorption coefficient becomes 30.

Unnecessary light other than the reference beam and the probe beam irradiated to the first and second light receiving elements 170 and 180 from the polarization mixer 160 is removed from the front ends of the first and second light receiving elements 170 and 180, First and second laser line filters 171 and 181 may be installed to prevent the laser beams from being incident on the first and second laser line filters 171 and 181, respectively.

The sample accommodating portion 190 may be provided between the polarizing beam splitter 130 and the retroreflector 120. Here, the sample accommodating portion 190 is made of a light-transmitting material, and the supply port 191 and the discharge port 192 are formed so as to collect various kinds of aerosols, And the supply port 191 and the discharge port 192 may be provided with valves for opening and closing the supply and discharge of the sample.

2 is a configuration diagram showing a light absorption coefficient measurement system of a sample according to a second embodiment of the present invention.

2, a system 200 for measuring a light absorption coefficient of a sample according to a second embodiment of the present invention includes a laser light source 210, A polarized beam-splitter 230 in which a polarizing beam splitter coating layer 231 and a reflective coating layer 232 are formed on a front surface 233 and a rear surface 234 of a retroreflector 220, And the first and second light receiving elements 270 and 280 and may further include a supply port 291 and an outlet port 292. The first and second light receiving elements 270 and 280 may include a light source unit 241, a light source unit 242, a variable retarder 250, a polarization mixer 260, 292 and may include first and second laser line filters 271 and 281 provided at the front ends of the first and second light receiving elements 270 and 280, In order to read the output voltages of the first and second light receiving elements 270 and 280, a calculation unit 300 may be provided However, the components other than the heating laser irradiation unit 240 have been described in detail with the same names in the optical absorption coefficient measurement system 100 of the sample according to the first embodiment of the present invention, and a description thereof will be omitted.

In this embodiment, the heating laser irradiation units 241, 242 and 243 include, for example, a heating laser beam source 241 for irradiating a heating laser beam, reflection members 242 and 243 for reflecting the heating laser beam irradiated from the heating laser beam source 241 to cross the probe beam, . ≪ / RTI > Here, the reflective members 242 and 243 may be formed in a plurality of, for example, mirrors, in order to control the path of the heating laser so that the heating laser does not affect the surrounding constituent members. As described above, the heating laser irradiation unit 240 according to the present embodiment can minimize the change in the refractive index due to external factors by heating only a part of the probe beam.

3 is a flow chart showing a method of measuring a light absorption coefficient of a sample according to an embodiment of the present invention.

Referring to FIG. 3, a method of measuring a light absorption coefficient of a sample according to an embodiment of the present invention includes measuring a light absorption coefficient of an aerosol as a sample using a light absorption coefficient measurement system (100, 200) A description overlapping with the description of the optical absorption coefficient measurement systems 100 and 200 of the sample according to the present invention will be omitted.

In the method of measuring the light absorption coefficient of a sample according to an embodiment of the present invention, the laser beams emitted from the laser light sources 110 and 210 are incident on the polarizing beam splitter coating layers 131 and 233 formed on the front surfaces 133 and 233 of the polarizing beam splitters 130 and 230 The reference beam and the probe beam are divided into a reference beam and a probe beam which are reflected and transmitted respectively and the reference beam and the probe beam are incident on the reflective coating layers 132 and 232 formed on the rear surfaces 134 and 234 of the retro- So as to pass through the region where the sample is located (S11). The step S11 of dividing and reflecting the laser beam into the reference beam and the probe beam by the polarizing beam splitter and reflecting the laser beam is performed by irradiating the polarizing beam splitter coating layers 131 and 231 partially formed on the front surfaces 133 and 233 of the polarizing beam splitters 130 and 230, And the reference beam reflected by the polarizing beam splitter coating layers 131 and 231 is reflected by the retro-reflectors 120 and 220 to be incident on the front surfaces 133 and 233 to pass the sample through the reference beams 131 and 231, And the polarizing beam splitter coating layers 131 and 231 are partially reflected on the rear surfaces of the reflective coating layers 132 and 232 and the polarizing beam splitter coating layers 131 and 231 and are transmitted to the outside, and the probe beam, which has passed through the polarizing beam splitter coating layers 131 and 231, 232 and the retro-reflectors 120 and 220 to be incident on the polarizing beam splitter coating layers 131 and 231 to pass through the sample, The probe beam is incident on a splitter coating (131 231) can be combined such that the reference beam transmitted through the transmission to the outside to the outside.

The reference beam and the probe beam passed through the polarizing beam splitters 130 and 230 pass through the polarization mixers 160 and 260 so that the respective reference planes of the reference beams And the probe beam, respectively, so as to be irradiated onto the first and second light receiving elements 170, 180, 270 and 280, respectively (S12).

By adjusting the polarization states of the reference beam and the probe beam by barrierblattters 150 and 250 provided on the front side of the polarization mixers 160 and 260 in a state where the sample is not positioned in the above-mentioned area, the first and second light- (Step S13).

After the above setting is completed, a heating laser is irradiated to the probe beam by the heating laser irradiation units 140, 241, 242 and 243 in a state where the sample is placed in the above-described area, for example, the aerosols collected in the atmosphere are supplied to the sample accommodating units 190 and 290 The refractive index of the probe beam is changed (S14). The step S14 of changing the refractive index of the probe beam may be performed by changing a heating laser from the polarization beam splitter coating layer 131 to the retroreflector 120 (as in the optical absorption coefficient measurement system 100 of the sample according to the first embodiment of the present invention) The heating laser can be irradiated to the position at which the probe beam reflected at the light source is incident on the probe beam. Alternatively, as in the light absorption coefficient measurement system 200 of the sample according to the second embodiment of the present invention, .

After the refractive index of the probe beam is changed, the difference between the voltage values output from the first and second light receiving elements 170, 180, 270, and 280 by the irradiation of the reference beam and the probe beam is read (S15). At this time, the difference of the voltage values may be performed by the calculation unit 300. [

(S16) calculating the light absorption coefficient by reading the difference between the voltage values output by the first and second light receiving elements 170, 180, 270 and 280, respectively. The step S16 of calculating the light absorption coefficient, The difference between the voltage values of the first and second light receiving elements 170, 180, 270 and 280, which are obtained for a specific substance having a specific concentration, And the light absorption coefficient of the sample can be calculated by calibrating the difference between the voltage values of the first and second light receiving elements 170, 180, 270, and 280 obtained on the sample to the reference value. Taking this as an example, since a light absorption coefficient for a specific concentration is known for a substance such as carbon dioxide (CO ₂ ), when the specific concentration of carbon dioxide is injected into a sample, the difference between the first and second light receiving elements 170, 180, 270 and 280 is measured The measured value may be a light absorption coefficient. Specifically, for example, if it is known that the light absorption coefficient of carbon dioxide of 10 ppm is 100, when 10 ppm of carbon dioxide is injected into the sample aerosol, the output voltage difference between the first and second light receiving elements 170, 180, , It becomes possible to calibrate 10 V to a light absorption coefficient of 100. Accordingly, when a specific aerosol is injected, if the output voltage difference of the first and second light receiving elements 170, 180, 270 and 280 is 3V, the light absorption coefficient becomes 30.

According to the system and method for measuring the optical absorption coefficient of the sample according to the present invention, it is possible to easily measure the optical absorption coefficient of a sample such as an atmospheric aerosol and to improve the accuracy of the measured value of the optical absorption coefficient .

Although the present invention has been described with reference to the accompanying drawings, it is to be understood that various changes and modifications may be made without departing from the spirit of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

110, 210: Laser light source 120, 220: Retro reflector
130, 230 polarizing beam splitter 131, 231 polarizing beam splitter coating layer
132, 232: reflection coating layer 133, 233:
134, 234: rear surface 140, 241, 242, 243:
150,250: Barrier titer 160,260: Polarization mixer
170, 270: first light receiving element 171, 271: first laser line filter
180, 280: second light receiving element 181, 281: second laser line filter
190, 290: sample accommodating portion 191:
192: outlet 300:

Claims (11)

As a system for measuring a light absorption coefficient using an aerosol as a sample,
A laser light source for irradiating a laser;
A retroreflector for reflecting the beam;
A polarizing beam splitter coating layer which is provided so as to position a sample between the reference beam and the retro-reflector and is divided into a reference beam and a probe beam by reflecting and transmitting a laser beam from the laser beam source, A polarizing beam splitter in which a reflective coating layer is formed which reflects the beam as it is reflected by the retroreflector to pass through the sample;
A heating laser irradiation unit for irradiating the probe beam with a heating laser to change the refractive index of the sample;
A polarization beam splitter that changes the polarization state of the reference beam and the probe beam that are combined through the polarization beam splitter;
A polarization mixer that splits the reference beam and the probe beam passed through the barrier bladder and rotates the polarization plane of the reference beam and the probe beam at a predetermined angle around the path direction; And
And a first and a second light receiving element for receiving the reference beam and the probe beam emitted from the polarization mixer, respectively, and converting the received reference beam and the probe beam into an electrical signal. The method according to claim 1,
Wherein the polarizing beam splitter comprises:
The reference beam reflected by the polarizing beam splitter coating layer is reflected by the retro reflector and is incident on the front surface of the polarizing beam splitter coating layer so as to pass through the sample, The reference beam incident on the front surface is reflected by the reflective coating layer and the rear surface of the polarizing beam splitter coating layer to be transmitted to the outside, and the probe beam transmitted through the polarizing beam splitter coating layer is reflected by the reflective coating layer and the retro- And the probe beam incident on the polarizing beam splitter coating layer is combined with the outwardly transmitted reference beam so as to be transmitted outward. The optical absorption coefficient measurement of the sample system. The method according to claim 1,
The heating laser irradiation unit
And the heating laser is irradiated to a position at which the probe beam reflected from the retro-reflector is incident in the polarization beam splitter coating layer. The method according to claim 1,
The heating laser irradiation unit
A heating laser light source for irradiating the heating laser; And
And a reflecting member for reflecting the heating laser emitted from the heating laser light source so as to cross the probe beam. The method according to claim 1,
The barrier rib detacher includes:
The reference beam and the probe beam are irradiated with the reference beam and the probe beam from the first and second light receiving elements in the state in which no sample is present and the heating laser is not irradiated from the heating laser irradiation unit, And adjusting the polarization state of the probe beam. The method according to claim 1,
Further comprising a sample accommodating portion which is provided between the polarizing beam splitter and the retro reflector and is made of a light transmissive material and in which a supply port and an exhaust port are formed so as to allow the aerosol to pass therethrough as the sample, . As a method for measuring a light absorption coefficient using an aerosol as a sample,
The laser beam is obliquely irradiated onto the polarizing beam splitter coating layer formed on the front surface of the polarizing beam splitter so as to be divided into the reference beam and the probe beam which are respectively reflected and transmitted, and the reference beam and the probe beam are reflected by the back surface of the retroreflector and the polarizing beam splitter Allowing the sample to pass through a region where the sample is located by being reflected by a reflection coating layer formed on the sample;
The reference beam and the probe beam passing through the polarizing beam splitter and passing through the polarizing mixer so that each of the polarizing planes is rotated at a predetermined angle around the path direction and the probe beam, 1 and the second light receiving element, respectively;
The polarized state of the reference beam and the probe beam is adjusted by the barrier bladder disposed on the front end of the polarization mixer without placing the sample in the area, so that the voltage value output from each of the first and second light- Setting the same;
Changing a refractive index of the probe beam by irradiating the probe beam with a heating laser while the sample is positioned in the region; And
And reading the difference between voltage values output from the first and second light receiving elements by irradiation of the reference beam and the probe beam, respectively. The method of claim 7,
Dividing and reflecting the laser beam into a reference beam and a probe beam by a polarization beam splitter,
Wherein the reference beam reflected by the polarizing beam splitter coating layer is reflected by the retro-reflector and is incident on the front surface of the polarizing beam splitter coating layer so that the reference beam reflected by the polarizing beam splitter coating layer is incident on the front surface of the polarizing beam splitter coating layer, The reference beam incident on the front surface is reflected by the reflective coating layer partially formed on the rear surface and the rear surface of the polarizing beam splitter coating layer so as to be transmitted to the outside, and the reference beam transmitted through the polarizing beam splitter coating layer The probe beam is reflected by the reflective coating layer and the retro-reflector and is incident on the polarizing beam splitter coating layer to pass through the sample. The probe beam incident on the polarizing beam splitter coating layer is combined with the reference beam transmitted to the outside, Outside So as to transmit the light absorption coefficient of the sample. The method of claim 7,
Wherein the step of changing the refractive index of the probe beam comprises:
And the heating laser is irradiated on the polarization beam splitter coating layer at a position where the probe beam reflected by the retro-reflector is incident. The method of claim 7,
Wherein the step of changing the refractive index of the probe beam comprises:
And irradiating the heating laser so as to cross the probe beam. The method of claim 7,
Further comprising the step of calculating a light absorption coefficient by reading a difference between voltage values output by the first and second light receiving elements, respectively,
Wherein the step of calculating the light absorption coefficient comprises:
The difference between the voltage values of the first and second light receiving elements obtained for a specific substance having a specific concentration of light absorption coefficient is read as a reference value, And calculating a light absorption coefficient of the sample by calibrating the light absorption coefficient at a reference value.

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