Iec 60793 1 34 2006

INTERNATIONALE IECINTERNATIONAL STANDARD 60793-1-34 Deuxième éditionSecond edition2006-03 Fibres optiques – Partie 1-34: Méthodes de mesure et procédures d'essai – Ondulation de la fib

Principe

One end of an uncoated fiber is mounted in a fixture that allows it to rotate freely, enabling the fiber's end to extend into space The length of the protrusion is adjustable based on the measurement device, with the typical extension distance ranging between specific limits.

When designing a measurement device with overhang distances greater than 10 mm and 20 mm, it is crucial to minimize excessive degradation caused by vibrations and gravity The fiber experiences rotation, and deviations in the overhang point's position relative to a reference point are measured to determine the fiber's curvature radius, denoted as $ r_c $.

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Part 1-34: Measurement methods and test procedures –

IEC 60793 outlines standardized requirements for the mechanical characteristic known as fibre curl or latent curvature in uncoated optical fibres This characteristic is crucial for reducing splice loss in optical fibres, particularly when employing passive alignment fusion splicers or active alignment mass fusion splicers.

Two methods are recognized for the measurement of fibre curl, in uncoated optical fibres:

Both techniques assess the radius of curvature of an uncoated fiber by measuring the deflection that occurs when an unsupported fiber end is rotated around its axis.

Method A employs visual or digital video techniques to assess fiber deflection, whereas Method B utilizes a line sensor to measure the maximum deflection of one laser beam in relation to a reference laser beam.

The radius of curvature of the fibre can be calculated by analyzing its deflection behavior as it rotates about its axis, taking into account the geometry of the measuring device, with detailed derivations provided in Annex C.

Both methods are applicable to types A1, A2, A3 and B optical fibres as described in the

Method A is the reference test method, used to resolve disputes

The following referenced documents are indispensable for the application of this document

For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

IEC 60793 (all parts), Optical fibres

An uncoated fibre end is positioned in a rotatable fixture, extending freely into space with an overhang distance typically ranging from 10 mm to 20 mm, depending on the measurement device For devices requiring greater overhang distances, it is crucial to manage potential degradation caused by vibration and gravity By rotating the fibre and measuring the deviations of the overhang point from a reference position, the fibre's radius of curvature, denoted as \$r_c\$, can be accurately determined.

Des précisions ayant trait aux deux méthodes sont fournies dans l’annexe correspondante A ou B Les exigences communes d’appareillage sont données ci-dessous.

Dispositif de fixation de la fibre

To ensure the fiber remains aligned and can rotate 360°, use a fixation device such as a V-groove support, suction chuck, or fiber ferrule When using a ferrule, it is crucial to match the inner diameter closely to the fiber diameter to minimize variability in deflection measurements.

Dispositif de rotation de la fibre

Utiliser un dispositif de fixation et de rotation de 360° Le dispositif peut être activé manuel- lement ou par un dispositif tournant tel qu'un moteur pas à pas.

Dispositif de mesure de la flèche

Utiliser un dispositif de mesure de la flèche conformément à l’une ou l’autre des Annexes A ou B.

Calculateur (facultatif)

Un calculateur peut être utilisé pour contrôler le processus, collecter les données et effectuer les calculs

Use a sufficiently long uncoated fiber for mounting on the measuring device One end of the fiber should be stripped adequately to provide enough overlap when secured in the fixture It is important not to exceed the required overlap distance for the measuring device, as excessive lengths may lead to degradation, as stated in Article 3.

Des précisions relatives à chaque méthode sont données dans les Annexes A et B Les procédures communes sont décrites ci-dessous.

Montage de la fibre

Install the fiber into the mounting device, ensuring that the stripped end extends freely and is long enough to reach or exceed the typical overhang distance Typical overhang distances range between

When attaching the fiber to the rotary device, ensure that the other end is secured properly If the overhang distance is too great or if the stripped fiber is significantly longer than the required overhang, the measurement may be compromised.

Rotation

Suivre la procédure de l’Annexe A ou l’Annexe B.

Principle

An uncoated fibre end is positioned in a rotatable fixture, extending freely into space with an overhang distance typically ranging from 10 mm to 20 mm, depending on the measurement device For devices requiring greater overhang distances, it is crucial to manage potential degradation caused by vibration and gravity By rotating the fibre and measuring the deviations of the overhang point from a reference position, the fibre's radius of curvature, denoted as \$r_c\$, can be accurately determined.

Des précisions ayant trait aux deux méthodes sont fournies dans l’annexe correspondante A ou B Les exigences communes d’appareillage sont données ci-dessous

3.2 Dispositif de fixation de la fibre

Use a fixation device to keep the fiber aligned on the same axis while allowing for a 360° rotation This fixation device can be a V-groove support, such as a suction chuck, or a fiber ferrule When using a ferrule, ensure that the inner diameter is closely calibrated to the fiber's diameter to minimize variability in deflection measurements.

3.3 Dispositif de rotation de la fibre

Utiliser un dispositif de fixation et de rotation de 360° Le dispositif peut être activé manuel- lement ou par un dispositif tournant tel qu'un moteur pas à pas

3.4 Dispositif de mesure de la flèche

Utiliser un dispositif de mesure de la flèche conformément à l’une ou l’autre des Annexes A ou B

Un calculateur peut être utilisé pour contrôler le processus, collecter les données et effectuer les calculs

Use a sufficiently long uncoated fiber for mounting on the measuring device One end of the fiber should be stripped adequately to provide enough excess once secured in the fixture It is important not to exceed the required excess length for the measuring device, as excessive lengths can lead to degradation, as noted in Article 3.

Des précisions relatives à chaque méthode sont données dans les Annexes A et B Les procédures communes sont décrites ci-dessous

Install the fiber into the mounting device, ensuring that the stripped end extends freely and is long enough to reach or exceed the typical overhang distances, which range between.

When attaching the fiber to the rotary device, ensure that the other end is secured properly If the overhang distance is too great or if the stripped fiber is significantly longer than the required overhang, the measurement may be compromised.

Suivre la procédure de l’Annexe A ou l’Annexe B

Faire le calcul détaillé de l’ondulation de fibre, r c , à l’aide de l’Annexe A ou de l’Annexe B

NOTE Bien que les paramètres intermédiaires utilisés dans les calculs soient généralement mis à l’échelle en micromètres, le rayon de courbure, r c, est généralement remis à l’échelle en unité de mètres

Details pertaining to the two methods are given in the relevant Annex A or B Common apparatus requirements are given below.

Fibre holding fixture

The fixture should securely hold the fibre on a constant axis while enabling 360° rotation Options for the fixture include a v-groove holder, vacuum chuck, or fibre ferrule When using a ferrule, it is crucial to ensure that the inside diameter closely matches the fibre diameter to reduce variability in deflection measurements.

Fibre rotator

Provide a device to grip and rotate the fibre through 360° The device may be manually operated, or may be driven by a rotational device such as a stepper motor.

Deflection measurement device

Provide a deflection measurement device according to either Annex A or Annex B.

Computer (optional)

A computer may be used to provide motion control, data collection and computation

For optimal instrument design, utilize an uncabled fiber of suitable length, ensuring to strip sufficient coating from one end for proper mounting in the fiber fixture with the required overhang It is crucial that the fiber does not extend significantly beyond the necessary overhang distance of the measuring device, as excessive lengths may lead to degradation, as outlined in Clause 3.

Details for each method are given in Annexes A and B Common procedures are described below.

Mounting of the fibre

Secure the fibre in the holding fixture, ensuring the stripped end extends into free space with a length sufficient to reach or exceed the typical overhang distance of 10 mm to 20 mm Connect the opposite end of the fibre to the fibre rotator Be cautious, as an excessive overhang distance or a significantly longer stripped fibre than necessary can lead to degraded measurement results.

Follow the procedure of Annex A or Annex B.

Calculation

Complete the detailed calculation of the fibre curl, r c , using Annex A or Annex B

NOTE Though the intermediate parameters used in the calculations are typically scaled in micrometres, the radius of curvature, r c , is typically re-scaled in units of metres

6.1 Il convient de consigner les informations suivantes à chaque essai:

• rayon de courbure de la fibre

6.2 Il convient que les informations suivantes soient disponibles à chaque essai:

• méthode d'essai utilisée pour déterminer l’ondulation;

La spécification particulière doit spécifier les informations suivantes:

• tout écart par rapport à la procédure;

• Les critères de défaillance ou d’acceptation

6.1 The following information should be reported for each test:

6.2 The following information should be available for each test:

• method used to determine curl;

The detail specification shall specify the following:

• any deviations to the procedure that apply;

Ondulation de fibre par microscopie latérale

This procedure measures the curvature radius of an uncoated fiber by determining the deflection value of an unsupported end of the fiber subjected to rotation around its axis The deflection amplitude of the fiber and the overhang distance between the fiber's fixation device and the measurement point enable the calculation of the fiber's curvature radius using a simple circular model, as described in Article C.1.

A.2 et A.3 présentent les schémas de montages d'essai typiques pour ces techniques

A.2.1 Dispositif de mesure de la flèche

Utiliser un dispositif permettant de mesurer la flèche de la fibre soumise à une rotation de

A 360° device may include an observation microscope or an optical measurement tool like a laser micrometer When using an observation microscope, it is essential to employ a method for accurately measuring the fiber's deflection, such as a wired eyepiece micrometer or a digital image analysis system.

Une caméra vidéo et un moniteur peuvent être utilisés pour améliorer le système d'observation du dispositif manuel ou automatisé

A.2.3 Système d'analyse de l'image numérique (facultatif)

A digital video analyzer can provide a more accurate localization of arrows compared to a wired ocular micrometer This system may include an analog or digital video camera, a screen-page sensor, and associated software to determine the fiber's position at the overflow distance when the fiber is subjected to rotation.

Two techniques are employed to obtain the deflection, δf The first technique involves identifying extremes, constrained by the accuracy with which these extremes can be determined The second method utilizes Fourier adjustment.

A.3.2 Procédure pour la technique des extrêmes

Apply a rotational movement to the test tube until the deflection reaches its maximum, and record the maximum deflection value, D max Then, continue the rotational movement until the deflection reaches its minimum, typically 180° from the maximum angular position, and record this minimum deflection value, D min.

Fibre curl by side view microscopy

This method assesses the radius of curvature of an uncoated fiber by measuring the deflection that occurs when an unsupported fiber end is rotated around its axis.

The radius of curvature of a fibre can be determined using a simple circular model by measuring the amplitude of deflection and the overhang distance from the fibre fixture to the measurement point, as detailed in Clause C.1 Typical test setups for these techniques are illustrated in Figures A.1, A.2, and A.3.

A device designed to measure fiber deflection through a full 360° rotation can include a viewing microscope or an optical measuring instrument like a laser micrometer When utilizing a viewing microscope, it is essential to incorporate tools for precise measurement of fiber deflection, such as a filar eyepiece or a digital image analysis system.

A video camera and monitor may be used to enhance the viewing system for manual or automated operation

A.2.3 Digital image analysis system (optional)

A digital video analyser offers enhanced accuracy in pinpointing deflections compared to traditional filar eyepieces This system typically comprises an analogue or digital video camera, a frame grabber, and specialized software designed to determine the fibre's position at the overhang distance during rotation.

Two methods are presented for calculating the deflection, denoted as \$\delta_f\$ The first method utilizes an extrema technique, which is constrained by the accuracy in identifying the extremes of the deflection.

The second is a Fourier fitting method

A.3.3 Procédure pour la technique d'ajustement de Fourier

Record the initial deflection value of the test specimen at position D1 and the angular position θ1 Rotate the specimen through 360° without duplicating the initial position in the data as the final angular position Mark stops at regular angular increments and record the deflection values at each increment, D2 n, along with their corresponding angular positions, θ2 n Commonly used angular increments range from 10° to 30°.

A.4.1 Calcul pour la technique des extrêmes

La flèche de la fibre δ f est calculée par l'équation:

2 min f = D max −D δ (A.1) ó D max et D min sont les valeurs de flèche maximale et minimale, exprimées généralement en micromètres

A.4.2 Calcul pour la technique d'ajustement de Fourier

Calculer les coefficients de Fourier du premier ordre:

Calculer δ f comme étant l’amplitude de Fourier du premier ordre:

The least squares adjustment of the set of parameters θ_i and D_i can be utilized variably The Fourier technique mentioned earlier and the least squares fitting of amplitude and phase are numerically equivalent.

A.4.3 Calcul de l’ondulation de la fibre

L’ondulation de la fibre, r c ,est calculée comme suit: f

= Z + r (A.5) ó Z m est la distance de débord

A.3.2 Procedure for the extrema technique

Rotate the specimen until the deflection is at a maximum and record the deflection value,

D max Rotate the specimen until the deflection is at a minimum, typically 180° from the angular position of the maximum, and record the deflection value, D min

A.3.3 Procedure for the Fourier fitting technique

Record the deflection of the specimen at its initial position, D 1 , and angular position, θ1

Rotate the specimen a full 360°, ensuring not to repeat the initial position as the final angular position Stop at equal angular increments, typically between 10° and 30°, and record the deflection values at each increment, denoted as D2 n, along with their corresponding angular positions, θ2 n.

The fibre deflection δf is calculated by:

2 min f = D max −D δ (A.1) where D max and D min are the maximum and minimum deflection values, generally described in micrometres

Compute the first order Fourier coefficients:

Compute δ f as the magnitude of the first-order Fourier component:

Least squares fitting of the sets of $ \theta_i $ and $ D_i $ serves as an effective alternative method Additionally, the Fourier technique previously discussed is numerically equivalent to the least squares fitting of both amplitude and phase.

Fibre curl, r c ,is computed as: f

= Z + r (A.5) where Z m is the overhang distance

Figure A.1 – Schéma d'appareillage pour mesurer l'ondulation de la fibre à l'aide d'un microscope optique

Faisceau de balayage Face de référence

Micromètre laser Moteur pas à pas

Figure A.2 – Schéma d'appareillage pour mesurer l'ondulation de la fibre à l'aide d'un micromètre laser

Figure A.1 – Schematic diagram for apparatus to measure fibre curl using an optical microscope

Figure A.2 – Schematic diagram for apparatus to measure fibre curl using a laser micrometer

Figure A.3 – Schéma d'appareillage pour mesurer l'ondulation de la fibre avec arrimage de l'échantillon dans une ferrule

Figure A.3 – Schematic diagram for apparatus to measure fibre curl while securing the sample in a ferrule

Mesure d'ondulation de fibre par diffusion de rayons laser

Cette méthode mesure de la courbure latente (ondulation) d'une fibre optique par diffusion de rayons laser

This procedure measures the curvature radius of an uncoated fiber by determining the deflection value of an unsupported end of the fiber subjected to rotation around its axis The differential deflection measurement of two beams separated by a known distance, along with the geometry of the measurement device, enables the calculation of the fiber's curvature radius using a simple circular model, as described in Article C.2.

Un schéma est représenté à la Figure B.1

Les faisceaux divisés d’un laser hélium – néon sont utilisés comme source lumineuse

Un capteur d'images tel qu’un capteur de lignes CCD est utilisé comme détecteur

Tiêu đề	Fibre Curl
Chuyên ngành	Optical Fibres
Thể loại	Standards Document
Năm xuất bản	2006

Định dạng
Số trang	42
Dung lượng	2,02 MB