JPH09210909A - Measuring device using laser beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the measuring accuracy of the concentration and temp. of molecules to be measured by determining the fluorescent intensity emitted from the molecules using a CCD camera, and subjecting the obtained intensity to a normalizing calculation process using a fluorescent intensity given by a sensor. SOLUTION: A pulse laser for energization 21 energizes a variable wavelength laser 22 to emit a laser beam 24, and a synch. signal is fed to a sensor 28 and a CCD camera 30 through a synch. line 31, and the intensity of the fluorescent beam emitted by a fluorescent substance applied to a glass plate 27 and the intensity of fluorescent beam emitted by molecules to be measured which are energized with the laser beam 24 cast onto the measuring field 26 are sensed and fed to a computer 32. The computer 32 performs a normalizing calculation process such that the fluorescent intensity of the molecules in the field 26 given from the camera 30 is divided by the fluorescent intensity given from the sensor 28, and the obtained quotient is displayed and emitted as the concentration or temp. of the molecules in the field 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device using laser light for measuring two-dimensional temperature and concentration using a laser induced fluorescence method.

[0002]

2. Description of the Related Art The laser-induced fluorescence method (hereinafter abbreviated as "LIF") irradiates a measuring field with a laser beam having the same frequency as an absorption line of a molecule to be measured to measure concentration and temperature. This is a method of obtaining the necessary signal light.

FIG. 2 shows a schematic structure of a conventional two-dimensional concentration measuring apparatus using LIF. Excitation pulsed laser 1
Oscillates a wavelength tunable laser 2 such as a dye laser to emit laser light having a wavelength corresponding to the electron energy difference of the molecule to be measured. The laser light is made into a sheet shape by the beam expander 3 and then incident on the measurement field 8.

Fluorescence generated from the molecule to be measured excited by the laser beam 7 with which the measurement field 8 is irradiated is condensed by the lens 4 and imaged and measured by the CCD camera 5. At this time, a synchronization line 6 is provided from the excitation pulse laser 1 to the CCD camera 5 for synchronizing laser oscillation and imaging.

Since the concentration of the molecule to be measured is proportional to the fluorescence intensity in the measurement field 8, the concentration of the molecule to be measured is determined by the fluorescence intensity, but at the same time, the fluorescence intensity is also proportional to the intensity of the laser beam 7. Therefore, it becomes necessary to correct the laser light intensity distribution in the measurement area irradiated with the laser light 7.

Conventionally, as a method for measuring the intensity distribution of the laser light 7, a method using Rayleigh scattered light from air (molecular scattered light having the same wavelength as the laser light), or as shown in FIG. After the beam expander 3 is provided with a beam splitter 11 for branching a part of the laser light 7, the laser light 7 branched by the beam splitter 11 is attenuated by a filter 12 to a convenient brightness for photographing. There has been a method of taking an image with the CCD camera 13 and detecting the intensity from the brightness.

[0007]

However, in the method of utilizing the Rayleigh scattered light from the measurement field when measuring the laser light intensity, it is necessary to introduce a buffer gas such as air into the measurement field. It was not possible to obtain the laser light intensity distribution while introducing the measurement molecule.

Further, in the method in which the laser beam 7 is branched by the beam splitter 11 shown in FIG. 3 and the branched laser beam is directly measured by the CCD camera 13, there is a problem such as interference in the measuring section of the CCD camera 13. There is a tendency that an error occurs easily.

The present invention has been made in view of the above circumstances, and an object of the present invention is to measure the intensity distribution of laser light with high accuracy while introducing a molecule to be measured. An object of the present invention is to provide a measuring device using a laser beam capable of measuring the concentration and temperature of a molecule to be measured in the field with high accuracy.

[0010]

Means for Solving the Problems That is, the present invention provides a beam expander for outputting a sheet-shaped laser beam to irradiate a molecule to be measured in a measurement field, and a fluorescence emitted from the molecule to be measured by irradiation with the laser beam. A first measuring means for measuring the fluorescence intensity by incidence, a beam splitter provided between the beam expander and the measurement field for branching a part of the laser beam, and a glass plate coated with a fluorescent material are provided with the above. A second measuring means for entering the laser beam split by the beam splitter to measure the fluorescence intensity emitted from the fluorescent substance, and a fluorescence intensity obtained by the second measuring means for obtaining by the first measuring means. And a normalizing means for normalizing the fluorescence intensity emitted by the molecule to be measured in the measurement field.

With this structure, the laser light intensity distribution can be corrected by the normalizing means to obtain the fluorescence intensity of the molecule to be measured, so that the concentration and temperature of the molecule to be measured are extremely high. It can be measured with accuracy.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A measuring device using laser light according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 exemplifies its schematic configuration. A pulse laser 21 for excitation is a wavelength tunable laser 2 such as a dye laser.
2 is oscillated, and laser light having a wavelength corresponding to the electron energy difference of the molecule to be measured is emitted.

The laser beam 24 emitted from the wavelength tunable laser 22 is formed into a sheet by the beam expander 23, and a part of the laser beam 24 is branched by the beam splitter 25 at a preset constant rate. The remaining laser light is directly incident on the measuring field 26, and the branched laser light is incident on the fluorescent substance-coated glass plate 27.

The glass plate 27 is attached to a detector 28 which is, for example, a CCD line sensor, and the detector 28 detects the intensity of fluorescence generated from the fluorescent substance applied to the glass plate 27 by using a laser. It is detected as representing the intensity distribution of the light 24.

On the other hand, the fluorescence generated from the molecule to be measured excited by the laser beam 24 applied to the measurement field 26 is
The light is condensed by the lens 29, and is imaged and measured by the CCD camera 30.

However, a synchronization line 31 is provided from the excitation pulse laser 21 to the detector 28 and the CCD camera 30, and laser oscillation, detection, and imaging are synchronized via the synchronization line 31. Signal is delivered.

Then, the fluorescence intensity corresponding to the intensity distribution of the laser beam 24 detected by the detector 28, and the CCD camera 3
The fluorescence intensities at the measurement field 8 obtained at 0 are both sent to the computer 32.

In the computer 32, the CCD camera 30
The fluorescence intensity emitted by the molecule to be measured in the measurement field 26 obtained in step 2 is normalized using the fluorescence intensity obtained in the detector 28 to correct the output of the CCD camera 30, and the calculation result The concentration or temperature of the molecule to be measured at 26 is obtained and displayed and output.

In the above structure, the excitation pulse laser 21 excites the wavelength tunable laser 22 to emit laser light, while the detector 28, via the synchronization line 31,
And the sync signal is sent to the CCD camera 30, and the glass plate 2
The intensity of the fluorescence generated from the fluorescent substance applied to 7 and the intensity of the fluorescence generated from the molecule to be measured excited by the laser beam 24 applied to the measurement field 26 are detected and sent to the computer 32.

The computer 32 uses the fluorescence intensity obtained by the detector 28 as a divisor, and the measurement field 26 obtained by the CCD camera 30.
The normalization operation for dividing the fluorescence intensity emitted by the molecule to be measured at is executed, and the quotient is displayed and output as the concentration or temperature of the molecule to be measured in the measurement field 26.

In this case, the reason why the intensity of the fluorescence generated from the fluorescent substance applied to the glass plate 27 is taken as a divisor is that the fluorescence intensity is proportional to the intensity distribution of the laser beam 24. The divisor is used to perform division on the fluorescence intensity emitted by the molecule to be measured in the measurement field 26 to perform normalization based on the intensity distribution of the laser light 24, and the molecule to be measured in the measurement field 26 with extremely high accuracy. It becomes possible to measure the concentration or temperature of.

[0022]

As described above, according to the present invention, by measuring the intensity distribution of the laser beam with high accuracy while introducing the molecule to be measured, as a result, the concentration and temperature of the molecule to be measured in the measuring field are measured. It is possible to provide a measuring device using a laser beam capable of measuring a high accuracy.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a two-dimensional concentration measuring apparatus using a general laser induced fluorescence method.

FIG. 3 is a diagram showing a configuration for measuring the intensity distribution of laser light in combination with FIG.

[Explanation of symbols]

 21 ... Excitation pulse laser 22 ... Wavelength variable laser 23 ... Beam expander 24 ... Laser light 25 ... Beam splitter 26 ... Measurement field 27 ... Glass plate 28 ... Detector 29 ... Lens 30 ... CCD camera 31 ... Synchronization line 32 ... Computer

Claims (1)

[Claims] 1. A beam expander for outputting a sheet-shaped laser beam to irradiate a molecule to be measured in a measurement field, and a fluorescence expander for injecting fluorescence emitted from the molecule to be measured by laser beam irradiation. 1 measuring means, a beam splitter provided between the beam expander and the measurement field to split a part of laser light, and a laser beam split by the beam splitter on a glass plate coated with a fluorescent substance. Second measuring means for measuring the fluorescence intensity emitted from the fluorescent substance, and the molecule to be measured in the measurement field obtained by the first measuring means by the fluorescence intensity obtained by the second measuring means A measuring device using a laser beam, comprising: a normalizing means for normalizing emitted fluorescence intensity.