JP2014020927A - Device for measuring transmittance of light guiding fiber and method for measuring transmittance of light guiding fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for measuring transmittance of a light guiding fiber and a method for measuring transmittance of the light guiding fiber which can accurately measure transmittance of the light guiding fiber even when the device has high tolerance for a connection posture of the light guiding fiber.SOLUTION: A device for measuring transmittance of a light guiding fiber comprises: a first integrating sphere 2 which radiates light by receiving light generated by a light source 1 then irregularly reflecting the received light; a second integrating sphere 5 which can selectively perform radiation of light by receiving the light radiated by the first integrating sphere 2 via a light guiding fiber 4 then irregularly reflecting the received light or radiation of light by receiving the light radiated by the first integrating sphere 2 without the light guiding fiber 4 then irregularly reflecting the received light; and a photometer 7 which receives the light radiated by the second integrating sphere.

Description

  The present invention relates to a light guide fiber transmittance measuring device and a light guide fiber transmittance measuring method.

As a prior art of the transmittance measuring device (and measuring method) of the light guide fiber, there is one disclosed in Patent Document 1, for example.
This light guide fiber transmittance measuring device uses an integrating sphere. The integrating sphere has two light receiving holes for receiving light emitted from the light source and two fiber mounting holes provided at positions different from the light receiving holes. Has a photometer.
When measuring the transmittance of the light guide fiber, the light transmitted through the light guide fiber is first detected with a photometer. That is, both ends of the light guide fiber to be measured are connected to the two fiber mounting holes of the integrating sphere, and the light generated by the light source on the two ends is passed through the spectroscope and the condensing lens from one light receiving hole. The inside of the integrating sphere is irradiated, and the illumination light (spectral) is incident on one end (incident end) of the light guiding fiber without being irregularly reflected by the inner surface of the integrating sphere. Then, the spectrum irradiated into the integrating sphere from the other end (outgoing end) of the light guide fiber is diffused and reflected many times by the inner surface of the integrating sphere, and the spectral distribution and intensity are made uniform. Illuminance is measured with a photometer.
Subsequently, the light (reference light) generated by the light source is detected by the photometer without passing through the light guide fiber. That is, the light (reference light) generated by the light source is irradiated into the integrating sphere from the other light receiving hole through the spectroscope and the condenser lens. Then, the spectrum irradiated into the integrating sphere is diffused and reflected many times by the inner surface of the integrating sphere without going to the light guiding fiber (spectral distribution and intensity are uniformed), and the illuminance and irradiance of each uniformed spectrum are Measured with a photometer.
After completing the above two types of measurements, if the measured value of the spectrophotometer transmitted through the light guide fiber is compared with the measured value of the reference light photometer, the measured value of the reference light (spectrum) is 100%. In this case, the transmittance of the light guide fiber can be obtained.

JP-A-5-157661

The light (spectrum) generated by the light source of the transmittance measuring device of Patent Document 1 is directly incident on the incident end of the light guide fiber without being irregularly reflected by the inner surface of the integrating sphere, so that its spectral distribution and intensity are not uniform. (The divergence of the light toward the incident end is not uniform). Therefore, if the connection posture (connection angle) of the light guide fiber with respect to the transmittance measurement device changes even slightly due to a defect in the fiber connection portion of the transmittance measurement device, the light incident on the incident end of the light guide fiber is changed. Divergence will change.
That is, it is difficult to accurately measure the transmittance of the light guide fiber unless the light guide fiber is accurately connected to the light guide fiber transmittance measuring device so as to have a predetermined posture.

  The present invention provides a light guide fiber transmittance measuring device and a light guide fiber transmittance measuring method capable of accurately measuring the transmittance of the light guide fiber even when the tolerance of the connection posture of the light guide fiber is loose. With the goal.

  The light guide fiber transmittance measuring device of the present invention receives a light generated by a light source, diffuses and reflects the light, and then emits the light through the light guide fiber. A second integrating sphere that can selectively emit light after being diffusely reflected, and receive light without being guided through the light guiding fiber and diffusely reflected, and the second integrating sphere is emitted. And a photometer for receiving light.

  A spectroscope that splits the light generated by the light source and sends it to the first integrating sphere, or a spectroscope that splits the light emitted by the second integrating sphere may be provided.

  In the light guide fiber transmittance measuring method of the present invention, the light generated by the light source is irregularly reflected by the first integrating sphere, and the light emitted after the first integrating sphere is irregularly reflected is second integrated via the light guiding fiber. A step of detecting light transmitted through a light guiding fiber, which is incident on the sphere and then diffused by the second integrating sphere, and measuring the light emitted by the photometer, and diffused by the first integrating sphere. Light emitted after irregular reflection by the first integrating sphere is received by the second integrating sphere without passing through the light guide fiber, and further, the light emitted after irregular reflection by the second integrating sphere is received by the photometer. And a comparison step of comparing the measured value of the photometer in the light guide fiber transmitted light detecting step with the measured value of the photometer in the reference light detecting step. It is characterized by.

  In the reference light detection step and the light guide fiber transmitted light detection step, the light generated by the light source is dispersed and sent to the first integrating sphere, or the light emitted by the second integrating sphere is dispersed. May be.

The light guide fiber transmittance measuring device and the light guide fiber transmittance measuring method according to the present invention can be used both when the transmitted light of the light guide fiber is measured with a photometer and when the reference light is measured with a photometer. After the light intensity generated by the light source is made uniform by the first integrating sphere, the uniformed light is made incident on the second integrating sphere through the light guiding fiber or not through the light guiding fiber. .
Dividing the light incident on the incident end of the light guide fiber if the measurement operation is performed several times while changing the connection posture (connection angle) of the light guide fiber to the light guide fiber transmittance measuring device little by little without making the light uniform. The degree changes every measurement work. In general, the light guide fiber has a characteristic that the transmittance changes when the divergence of the light incident on the incident end changes. Therefore, the light guide fiber transmits when the divergence of the light incident on the incident end of the light guide fiber changes. The rate cannot be measured accurately.
However, if the measurement work is performed a plurality of times while making the light uniform as in the present invention, even if the connection posture (connection angle) of the light guide fiber to the light guide fiber transmittance measuring device changes somewhat for each measurement work, The divergence of light incident on the incident end of the light guide fiber is almost constant each time. Therefore, the transmittance of the light guide fiber can be accurately measured even if the connection posture of the light guide fiber is somewhat bad.

It is a figure which shows the state which measures the light radiate | emitted from the light guide fiber using the light guide fiber transmittance | permeability measuring apparatus to which one Embodiment of this invention is applied. It is a figure which shows the state which measures reference light using a light guide fiber transmittance measuring device.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
The light guide fiber transmittance measuring device 10 is a device including a first integrating sphere 2, a diaphragm 3, a second integrating sphere 5, and a photometer 7.
A first integrating sphere 2 to which a light source 1 (lamp, LED, etc.) having a condenser lens (not shown) is attached in a fixed state has an exit hole 2a, and a diaphragm 3 is attached to and detached from the exit hole 2a in a concentric state. It is fixed as possible. The photometer probe 6 of the photometer 7 is connected to the second integrating sphere 5 having the incident hole 5a. The photometer 7 has a built-in spectroscope that splits the light incident on the photometer probe 6, and further has a function of measuring the illuminance and irradiance of each spectrum divided by the spectroscope.

Then, the transmittance | permeability measuring method of the light guide fiber 4 using the light guide fiber transmittance measuring apparatus 10 is demonstrated.
First, the light transmitted through the light guide fiber 4 (white light spectrum) is measured (received) by the photometer 7. That is, as shown in FIG. 1, both ends of the light guide fiber 4 are connected to the exit hole 2a (the diaphragm 3 is removed) of the first integrating sphere 2 and the entrance hole 5a of the second integrating sphere 5, respectively. White light generated by the light source 1 is irradiated to the inside of the first integrating sphere 2 through the condenser lens. Then, the white light is diffused and reflected many times by the inner surface of the first integrating sphere 2 to make the intensity uniform, and the uniformed white light is irradiated to the incident end of the light guide fiber 4. The white light incident on the light guide fiber 4 is irradiated from the exit end of the light guide fiber 4 to the inside of the second integrating sphere 5 through the incident hole 5a, and is diffused and reflected many times by the inner surface of the second integrating sphere 5. It is made uniform. A photometer 7 connected to the second integrating sphere 5 via the photometer probe 6 divides white light into a plurality of spectra having different wavelengths, and measures the illuminance and irradiance of each spectrum.
Subsequently, the light (reference light) generated by the light source 1 is measured (received) by the photometer 7 without passing through the light guide fiber 4. That is, as shown in FIG. 2, the exit hole 2a (fixing the diaphragm 3) of the first integrating sphere 2 and the entrance hole 5a of the second integrating sphere 5 are directly connected, and the white light generated by the light source 1 is then connected thereto. The first integrating sphere 2 is irradiated through the condenser lens. Then, the white light irradiated into the first integrating sphere 2 is diffused and reflected many times by the inner surface of the first integrating sphere 2 to make the intensity uniform, and the uniformed white light passes through the aperture 3 through the entrance hole 5a. The two integrating spheres 5 are irradiated inside. The white light irradiated to the inside of the second integrating sphere 5 was scattered irregularly many times by the inner surface of the second integrating sphere 5 to make the intensity uniform, and then divided into a plurality of spectra having different wavelengths by the photometer 7. Above, illuminance and irradiance are measured by the photometer 7.
After the above two types of measurements are completed, if the measured value of the reference light photometer 7 is compared with the measured value of the spectrophotometer 7 transmitted through the light guide fiber 4, the reference light (spectrum) is measured. The transmittance of the light guide fiber 4 when the value is 100% can be obtained.

  In the method for measuring the transmittance of the light guide fiber 4 using the light guide fiber transmittance measuring device 10 of this embodiment, the transmitted light of the light guide fiber 4 is measured with the photometer 7 and the reference light is measured with the photometer 7. In any case of measurement, the intensity of the white light generated by the light source 1 is made uniform by the first integrating sphere 2, and then the uniformed white light is passed through the light guide fiber 4 or the light guide fiber 4. Then, the light is incident on the second integrating sphere 5 and the illuminance and irradiance of the spectrum are then measured by the photometer 7. If the white light incident on the light guide fiber 4 and the white light emitted by the light guide fiber 4 are made uniform, the connection posture of the light guide fiber 4 with respect to the light guide fiber transmittance measuring device 10 when performing a plurality of measurement operations. Even if the (connection angle) is slightly changed for each measurement operation (due to a defect in the fiber connection portion of the light guide fiber transmittance measuring device 10), the divergence of light incident on the incident end of the light guide fiber 4 Is almost constant each time. Therefore, the transmittance of the light guide fiber 4 can be accurately measured even if the connection posture of the light guide fiber 4 with respect to the light guide fiber transmittance measuring device 10 (the first integrating sphere 2 and the second integrating sphere 5) is somewhat bad. .

As mentioned above, although this invention was demonstrated using the said embodiment, this invention can be implemented, giving various deformation | transformation.
For example, the spectroscope may be eliminated from the photometer 7 and a spectroscope may be provided between the light source 1 and the first integrating sphere 2.
Further, the transmittance of the light guide fiber 4 related to white light (generated by the light source 1) may be measured by eliminating the spectroscope from the light guide fiber transmittance measuring device 10.

DESCRIPTION OF SYMBOLS 1 Light source 2 1st integrating sphere 2a Outgoing hole 3 Diaphragm 4 Light guide fiber 5 2nd integrating sphere 5a Incident hole 6 Photometer probe 7 Photometer 10 Light guide fiber transmittance measuring device

Claims (4)

A first integrating sphere that receives the light generated by the light source, diffuses it, and emits it;
Selectively emitting the light emitted from the first integrating sphere after receiving and irregularly reflecting the light through the light guiding fiber, and emitting the light after receiving and irregularly reflecting without passing through the light guiding fiber. A second integrating sphere capable of
A photometer for receiving the light emitted by the second integrating sphere;
A light guide fiber transmittance measuring device comprising: In the light guide fiber transmittance measuring device according to claim 1,
A light guide fiber transmittance measuring device provided with a spectroscope that splits the light generated by the light source and sends it to the first integrating sphere, or a spectroscope that splits the light emitted from the second integrating sphere. The light generated by the light source is diffusely reflected by the first integrating sphere, and the first integrating sphere is diffusely reflected, and the emitted light is incident on the second integrating sphere through the light guide fiber, and the second integrating sphere is irregularly reflected. A light guide fiber transmitted light detecting step for measuring the emitted light with a photometer
The light generated by the light source is irregularly reflected by the first integrating sphere, the light emitted after the first integrating sphere is irregularly reflected is received by the second integrating sphere without passing through the light guide fiber, and the A reference light detection step for receiving light emitted by the second integrating sphere after irregular reflection by the photometer, and
A comparison step for comparing the measurement value of the photometer in the light guide fiber transmitted light detection step with the measurement value of the photometer in the reference light detection step;
A method for measuring the transmittance of a light guide fiber, comprising: In the light guide fiber transmittance measuring method according to claim 3,
In the reference light detection step and the light guide fiber transmitted light detection step, the light generated by the light source is dispersed and sent to the first integrating sphere, or the light emitted from the second integrating sphere is dispersed. Light guide fiber transmittance measurement method.

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