JPH04331366A - Zirconia ferrule evaluator - Google Patents

Abstract

PURPOSE:To achieve a highly accurate evaluation of flaws and pollution of the surface and below the surface automatically by irradiating the surface of zirconia ferrule with a laser beam to detect a sound wave associated with light absorption and radiation less transition with a microphone. CONSTITUTION:A light source uses a He-Ne laser 1 and the light is separated spectrally into a part for irradiating zirconia ferrule 6 as sample and a part to be taken into a lockin amplifier 12 as reference signal. The laser on the side of the sample is modulated to be an intermittent light of 1kHz with an A/O modulator 2 to scan the ferrule 6 in a longitudinal direction with a scanner 4. A sample cell 5 is equipped with a microphone 7 for coarse or dense wave detection, a leak value 13 for preventing a rise in internal pressure during the introduction of the sample and a stepping motor 8 for rotating the ferrule 6. With the irradiation of the intermittent light, the coarse or dense wave generated with the ferrule 6 is detected with the microphone 7 and after amplified with a preamplifier 12 and the lockin amplifier 12, the wave is inputted into a CPU 9 as photoacoustic signal.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaluation device for zirconia ferrules for optical fiber connectors.

0002

BACKGROUND OF THE INVENTION Hitherto, evaluation of scratches, stains, etc. on zirconia ferrules has been carried out by human visual observation.

0003

[Problems to be Solved by the Invention] Evaluation of scratches, stains, etc. on zirconia ferrules is performed by human observation by human eyes, which causes problems such as oversights and the inability to automate the evaluation.

0004

[Means for Solving the Problems] According to the device of the present invention,
Instead of observing with the naked eye, a laser beam (intermittent) is irradiated and the sound waves accompanying light absorption and non-radiative transition generated from the zirconia ferrule are detected using a microphone, making it possible to discover scratches and dirt on the surface of the zirconia ferrule. .

[0005]

[Operation] When a material is irradiated with intermittent light, a portion of the light energy absorbed into the material generates heat within the material, and leaks into the surrounding gas due to subsequent thermal diffusion. Since it is an intermittent beam, compression waves are generated in the surrounding gas, which can be detected with a microphone. This phenomenon is generally called the photoacoustic effect, and the compression waves generated are called photoacoustic signals. By applying this photoacoustic effect,
It is possible to evaluate scratches on the zirconia ferrule surface and within the subsurface thermal diffusion length, as well as stains that have optical and thermal characteristics different from those of zirconia. Furthermore, by narrowing down the beam of the light source, the surface resolution increases, and by increasing the intensity of the beam, the intensity of the photoacoustic signal can be increased, making precise measurements possible.

[0006]

Embodiment FIG. 1 shows a block diagram of a zirconia ferrule evaluation device. A He-Ne laser 1 was used as a light source. The laser beam is divided by a beam splitter 3 into a side where it is irradiated onto a zirconia ferrule 6, which is a sample, and a side where it is taken into a lock-in amplifier 12 as a reference signal. The laser beam on the sample side is transmitted to the A/O modulator 2.
The intermittent light is modulated to 1 kHz and illuminates the sample while being scanned in the longitudinal direction of the zirconia ferrule 6 by the scanner 4. At this time, since the zirconia ferrule 6 is rotated by a stepping motor, the intermittent light is irradiated all over the side surface of the zirconia ferrule 6.

FIG. 2 shows a cross-sectional view of the sample cell. Inner diameter 5m
A zirconia ferrule 6 is placed in a quartz tube 14 of size m, and the tube is sealed with an O-ring 15. The sample cell 5 is equipped with a microphone 7 for detecting compressional waves, a leak valve 13 for preventing an increase in internal pressure when introducing a sample, and a stepping motor 8 for rotating the zirconia ferrule 6. Compression waves generated from the zirconia ferrule 6 due to intermittent light irradiation are detected by a microphone 7, amplified by a preamplifier (not shown) and a lock-in amplifier 12, and then taken into the CPU 9 as a photoacoustic signal. The results are output to a monitor (not shown) and plotter 10.

FIG. 3 shows the output results according to the present invention. The X axis represents the rotation angle, the Y axis represents the distance in the longitudinal direction of the zirconia ferrule, and the Z axis represents the signal intensity. Vertical peaks near rotation angles of 30 degrees and 210 degrees indicate the presence of defects or internal non-uniformity caused by weld lines during injection molding. A peak near 150 degrees indicates the presence of contamination at the surface or within the subsurface thermal diffusion length. Furthermore, since the photoacoustic signal due to dirt or defects beneath the surface has a time delay compared to that on the surface, it is possible to observe the phase of the photoacoustic signal output from the lock-in amplifier in a non-destructive manner. Information will be obtained.

[0009]

EFFECTS OF THE INVENTION As described in the embodiments above, the apparatus of the present invention is capable of accurately evaluating zirconia ferrules for scratches and stains, which was conventionally done by humans. It can also detect scratches and dirt beneath the surface that are impossible to see with the naked eye. Furthermore, it is an industrially superior device that can be easily incorporated into a line by adding a device for introducing it into a sample cell and taking it out.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a sectional view showing essential parts of the present invention.

FIG. 3 is an output result diagram according to the present invention.

[Explanation of symbols]

1 He-Ne laser 6 Zirconia ferrule 7. Microphone

Claims (1)

[Claims] Claim 1: In the evaluation of zirconia ferrules, the zirconia ferrules are intermittently irradiated with a laser beam, and the sound waves accompanying the light absorption and non-radiative transition generated from the zirconia ferrules are detected by a microphone, thereby eliminating scratches on the surface of the zirconia ferrules. A zirconia ferrule evaluation device characterized by evaluating dirt, dirt, etc.