GB/T 15972.43-2021Specifications for optical fibre test methods - Part 43: Measurement methods and test procedures for transmission characteristics - Numerical aperture (English PDF)

Foreword

GB/T 15972 "Specifications for Optical Fiber Test Methods" consists of several parts, and its expected structure and corresponding international standards are.

---Part 10.General principles of measurement methods and test procedures (corresponding to IEC 60793-1-1);

---Part 20~Part 29.Measurement methods and test procedures of dimensional parameters (corresponding to IEC 60793-1-20 to IEC 60793-

1-29);

---Part 30~Part 39.Measurement methods and test procedures of mechanical properties (corresponding to IEC 60793-1-30 to IEC 60793-

1-39);

---Part 40~Part 49.Measurement methods and test procedures of transmission characteristics (corresponding to IEC 60793-1-40 to IEC 60793-

1-49);

---Part 50~Part 59.Environmental performance measurement methods and test procedures (corresponding to IEC 60793-1-50 to IEC 60793-

1-59).

Among them, GB/T 15972.40~49 consists of the following parts.

---Part 40.Measurement methods and test procedures for transmission characteristics attenuation;

---Part 41.Measurement methods of transmission characteristics and test procedure bandwidth;

---Part 42.Measurement methods and test procedures for transmission characteristics. Wavelength dispersion;

---Part 43.Measurement methods of transmission characteristics and test procedures numerical aperture;

---Part 44.Measurement methods of transmission characteristics and test procedures cut-off wavelength;

---Part 45.Measurement methods and test procedures for transmission characteristics; Mode field diameter;

---Part 46.Transmission characteristics measurement methods and test procedures light transmittance changes;

---Part 47.Measurement methods and test procedures for transmission characteristics, macrobending loss;

---Part 48.Measurement methods and test procedures for transmission characteristics Polarization mode dispersion;

---Part 49.Differential modulus delay for measurement methods and test procedures of transmission characteristics.

This part is part 43 of GB/T 15972.

This section was drafted in accordance with the rules given in GB/T 1.1-2009.

This part replaces GB/T 15972.43-2008 "Specification for optical fiber test methods Part 43.Measurement of transmission characteristics and optical characteristics

Methods and Test Methods Numerical Aperture." Compared with GB/T 15972.43-2008, the main technical changes in this part are as follows.

---Modified the name of the standard;

---Added the technical requirements for A3 and A4 multimode fibers (see Chapter 1, 5.2.5, Appendix B);

---Added abbreviations and symbols (see Chapter 3);

--- Deleted the formula for calculating the theoretical numerical aperture using the relative refractive index difference (see Chapter 3 of the.2008 edition);

--- Deleted the far-field light intensity distribution method test device (see Figure 1 of the.2008 edition);

---Modified the requirements of the central wavelength of the light source (see 5.1.2, 4.2.2 of the.2008 edition);

---The effective size of the detector or the diameter of the pinhole in Method 1 is added (see 5.2.2.2); the straightness of the reproduction lens L2 is deleted

Diameter requirements (see 4.3.3.2 in the.2008 edition); delete the requirements for light detectors (see 4.3.4 in the.2008 edition); add method 3

Requirements for optical detectors (see 5.2.4.7); Method 3 is added to calculate the far-field intensity (see 8.4);

---Added method 4 inverse far-field method (see 5.2.5); added method 4 to calculate numerical aperture (NAff) (see 8.5);

---Modified the requirements of the sample length, and revised the typical sample length of 2m+/-0.2m to the requirements in the product specification (see 6.1,

1 Scope

This part of GB/T 15972 specifies the test method of optical fiber numerical aperture, and establishes the test equipment, sample preparation, procedure, calculation

And the unified requirements of the results.

This section applies to A1, A2, A3, and A4 multimode optical fibers and cables.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article

Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 12357.1 Multimode Optical Fiber for Communication Part 1.Characteristics of Type A1 Multimode Optical Fiber (GB/T 12357.1-2015, IEC

60793-2-10.2011, MOD)

GB/T 12357.2 Multimode Optical Fiber for Communication Part 2.Characteristics of Type A2 Multimode Optical Fiber (GB/T 12357.2-2004, IEC

60793-2-20,.2002, MOD)

GB/T 12357.3 Multimode Optical Fiber for Communication Part 3.Characteristics of Type A3 Multimode Optical Fiber (GB/T 12357.3-2004, IEC

60793-2-30.2002, MOD)

GB/T 12357.4 Multimode Optical Fiber for Communication Part 4.Characteristics of Type A4 Multimode Optical Fiber (GB/T 12357.4-2016, IEC

60793-2-40.2009, MOD)

GB/T 15972.10 Optical fiber test method specification Part 10.General rules of measurement methods and test procedures (GB/T 15972.10-

2021, IEC 60793-1-1.2017, MOD)

3 Symbols and abbreviations

The following abbreviations and symbols apply to this document.

KNA threshold percentage (Thresholdpercentage)

NA Numerical Aperture (Numericalaperture)

NAff far-field numerical aperture (Far-fieldnumericalaperture)

NAth Maximum theoretical numerical aperture (Maximumtheoreticalnumericalaperture)

RTM benchmark test method (Referencetestmethod)

4 Method overview

NA is an important parameter of A1, A2, A3, and A4 multimode fibers. It indicates the ability of the fiber to collect optical power. It is used

Predict the injection efficiency, splicing loss and microbending and macrobending performance of the optical fiber.

The numerical aperture can be defined by measuring the far-field distribution. In some cases, NAth is also used. NAth can be determined by the fiber core and cladding.