JPH0454421Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a laser scattering light measurement device, especially for weak light scattering where light scattered by the optical system in the laser beam path port, tube wall, etc. is a problem. The present invention relates to a laser scattered light measuring device for performing measurements.

[Conventional technology]

Conventional laser scattered light measurement devices have had a problem in that light scattered by optical systems, tube walls, etc. in the laser light input port and the laser light output port largely wraps around within the field of view to be measured.

[Problem to be solved by the invention] Therefore, the above-mentioned conventional laser scattered light measurement device does not measure the light scattered by the optical system or tube wall in the laser light input port and the laser light output port. The drawback was that the laser scattered light from a small amount of gas could not be measured because the laser beam was largely wrapped around the field of view.

[Means for solving problems]

The laser scattered light measuring device of the present invention has a cylinder with a total length of 1 as long as possible, which can be inserted into a laser beam input port and a light output port, respectively, and a cylinder with a length of 0:1/4L:
It includes a buttful assembly consisting of a buttful with an edged tip and having an aperture 2.5 to 3 times the diameter of the incident laser beam partitioned in a ratio of 1/8l:1/4l:1/8l:1/4l. configured.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the laser scattered light measuring device shown in FIG.
The vacuum chamber 4 has a laser beam input port 1, a laser beam output port 2, and a laser scattered light observation port 3, and the amount of gas B inside is controlled by a gas supply/exhaust system 5.

Laser light A enters the inside of vacuum chamber 4 from laser light input port 1, and laser scattered light C scattered by gas B inside passes through laser scattered light observation port 3 and is condensed by condensing lens 6. The spectroscopic detection section 7 spectrally spectra and photoelectrically converts the light.

At this time, the baffle assembly 8 is inserted so that the optical system in the laser beam input port 1 and the laser beam output port 2 and the laser scattered light C on the pipe wall do not enter the field of view to be measured.

FIG. 2 is a central sectional view showing details of the buttful assembly 8 shown in FIG. 1.

The buttful assembly 8 includes a cylinder 9 that can be inserted into the laser beam input port 1 and the laser beam output port 2, and has a total length l as long as possible, and the cylinder interior is 0:1/4l:1/8.
It is composed of a buff-full 10 with an edged tip and a diameter 2.5 to 3 times the diameter of the incident laser beam partitioned in the ratio 1:1/4l:1/8l:1/4l.

FIG. 3 is a graph showing the relationship between the buffling interval and stray light in the embodiment shown in FIG. 1, and shows the results of evaluating stray light that wraps around within the field of view to be measured.

Batsuful 10 is all about the diameter of the incident laser beam.
It uses an edged tip with a diameter 2.5 times larger.

In Fig. 3, the state without the full assembly 8 is
The other cross marks are when the intervals between the buttfuls are equal. The baffle assembly used in the present invention is shown by the circle mark, and stray light is significantly reduced.

[Effect of idea]

The laser scattered light measurement device of the present invention inserts a buff-full assembly into the laser beam input port and laser beam output port, and optimizes the buff-full assembly to reduce stray light by approximately 2.
The effect is that it can be reduced to ×10 ^-3 .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.
2 is a central cross-sectional view showing details of the buffle assembly shown in FIG. 1, and FIG. 3 is a graph showing the relationship between the buffle spacing and stray light in the embodiment shown in FIG. 1. 1... Laser light input port, 2... Laser light output port, 3... Laser scattered light observation port, 4...
...Vacuum chamber, 5...Gas supply and exhaust system, 6...Condensing lens, 7...Spectral detection unit, 8...Boutful assembly, 9...Cylinder, 10...Boutful, A, D...Laser beam, B...Gas, C...Laser scattered light.

Claims (1)

[Scope of utility model registration request] a laser beam input port into which the laser beam is input;
a laser scattered light observation port that guides the scattered laser light out of the laser light; a laser light output port that guides the output laser light out of the laser light; the laser light input port and the laser light output port; A vacuum chamber to which a laser scattered light observation port is connected, a gas supply/exhaust system for controlling the amount of gas in the vacuum chamber, and a gas supply/exhaust system that can be inserted into the laser light input port and the laser light output port, respectively. The cylinder with the longest total length l and the inside of the cylinder are 0:1/4l:1/8l:1/4
1. Laser scattering, characterized in that it includes a buttful assembly consisting of a buttful with an edged tip and having an aperture 2.5 to 3 times the diameter of the incident laser beam partitioned in a ratio of 1:1/8l:1/4l. Light measurement device.