Optical Fiber Types

Nomenclature For Optical Fibers And Cross Reference To International Standards


Singlemode Fiber Types

There are several designations used to describe various types of singlemode fiber that are often confusing. Here is a cross-reference of the ones in common use today.

Description	ITU-T Recommendation	IEC 60793-2-50:2015	TIA
Dispersion unshifted single-mode optical fibers	G.652
	G.652.B	B1.1	492CAAC (Formerly 492CAAA)
- With low water peak	G.652.D	B1.3	492CAAC (Formerly 492CAAB)
Dispersion shifted single-mode optical fibers	G.653
	G.653.A	B2_a	492CAAC (Formerly N/A)
	G.653.B	B2_b	492CAAC (Formerly N/A)
Cut-off shifted single-mode optical fibers	G.654
	G.654.A	B1.2_a	492CAAC (Formerly N/A)
	G.654.B	B1.2_b	492CAAC (Formerly N/A)
	G.654.C	B1.2_c	492CAAC (Formerly N/A)
	G.654.D	N/A	N/A
	G.654.E	N/A	N/A
Non-zero dispersion shifted single-mode optical fibers	G.655	B4	(Formerly 492E000 sectional specification)
	G.655.C	B4_c	492CAAC (Formerly N/A)
	G.655.D	B4_d	492CAAC (Formerly N/A)
	G.655.E	B4_e	492CAAC (Formerly N/A)
Wideband non-zero dispersion shifted single-mode optical fibers	G.656	B5	492CAAC (Formerly N/A)
Bending loss insensitive single-mode optical fibers	G.657	B6
	G.657.A1	B6_a1	492CAAC (Formerly N/A)
	G.657.A2	B6_a2	492CAAC (Formerly N/A)
	G.657.B2	B6_b2	492CAAC (Formerly N/A)
	G.657.B3	B6_b3	492CAAC

From IEC 60793-2-50:2018

The standards bodies with vested interest in the governance of optical fiber specifications are:

ISO (International Organization for Standardization) – Formed of manufacturers and standards bodies representing over 90 nations. For optical fiber specifications and standards, ISO and IEC collaborate on several Joint Technical Committees (JTC).
IEC (International Electrotechnical Commission) – IEC addresses the electronics and telecommunications industries, and counts over 50 nations among its membership. The current IEEE 802.3 standard for Ethernet cites TIA-568 and ISO/IEC 11801 for optical fiber specifications.
TIA (Telecommunications Industry Association) – Now part of the Electronic Industries Alliance (EIA). TIA is comprised of manufacturers who are primarily suppliers to the telecom industry but include other interested groups. TIA is primarily involved (through the American National Standards Institute or ANSI) in optical fiber and system test standards.
ITU (International Telecommunication Union) – The ITU is part of the United Nations System of Organizations, and over 180 countries currently are represented within the ITU. The ITU administers the commonly referenced single-mode fiber standards documents, G.652 through G.655, as required by telecom systems manufcturers and their customers.

ITU Standards

The ITU has defined a series of recommendations that describe the geometrical properties and transmissive properties of multimode and single-mode fiber-optic cables. The four most important recommendations are listed here:
ITU G.651    Covers multimode 50/125 micron graded-index fiber.
ITU G.652    Covers single-mode NDSF (non-dispersion-shifted fiber). This fiber is in most of the cable that was installed in the 1980s. Optimized in the 1,310-nm range. Low water peak fiber has been specifically processed to reduce the water peak at 1400 nm to allow use in that range. There are 4 subcategories:
G.652A :
   Atten </= 0.5 / 0.4 at 1310 / 1550nm
Macrobend </= 0.5 dB at 1550nm
PMD </= 0.5 ps/sqrt(km)

G.652B :
   Atten </= 0.4 / 0.35 / 0.4 at 1310 / 1550 / 1625nm
Macrobend </= 0.5 dB at 1625nm
PMD </= 0.2 ps/sqrt(km)

G.652C :
   Atten </= 0.4 from 1310 to 1625nm, </= 0.3 at 1550nm, and
at 1383nm, it must be </= that specified at 1310nm, after hydrogen aging.
Macrobend </= 0.5 dB at 1625nm
PMD </= 0.5 ps/sqrt(km)

G.652D (covers all above):
   Atten </= 0.4 from 1310 to 1625nm, </= 0.3 at 1550nm, and
at 1383nm, it must be </= that specified at 1310nm, after hydrogen aging.
Macrobend </= 0.5 dB at 1625nm
PMD </= 0.2 ps/sqrt(km)

ITU G.653    Covers single-mode dispersion-shifted optical fiber. Dispersion is minimized in the 1,550-nm wavelength range. At this range attenuation is also minimized, so longer distance cables are possible.

ITU G.654: Covers single-mode fibre which has the zero-dispersion wavelength around 1300 m wavelength which is cut-off shifted and loss minimized at a wavelength around 1550 nm and which is optimized for use in the 1500-1600 nm region.

ITU G.655    Covers single-mode NZ-DSF (nonzero dispersion-shifted) fiber) , which takes advantage of dispersion characteristics that suppress the growth of four-wave mixing, a problem with WDM (wavelength division multiplexing) systems. NZ-DSF supports high-power signals and longer distances, as well as closely spaced DWDM (dense WDM) channels at rates of 10 Gbits/sec or higher. G.655 is optimized for WDM and long-distance cable runs such as transoceanic cables. It uses dispersion to reduce the effect of four-wave mixing (FWM), which occurs in DWDM systems when three wavelengths mix in such a way to produce a fourth wavelength that overlays and interferes with the original signals.

ITU G.657 Covers bend-insensitive single- mode fiber.

G.652D-compliant designations for long- reach applications:
G.657.A1 (10 mm minimum design radius)
G.657.A2 (7.5 mm minimum design radius)
and these G.652-compatible designations for short-reach (< 1 km) drop applications:
G.657.B2 (7.5 mm minimum design radius)
G.657.B3 (5 mm minimum design radius)

TIA Standards (Historical, changed as above table notes)

TIA TIA-492C000        EN-Sectional Specification for Class IVa Dispersion-Unshifed Single-Mode Optical Fibers
TIA TIA-492CA00        EN-Blank Detail Specification for Class IVa Dispersion-Unshifted Single Mode Optical Fibers
TIA TIA-492CAAA        EN-Detail Specification for Class IVa Dispersion-Unshifted Single-Mode Optical Fibers
TIA TIA-492CAAB        EN-Detail Specification for Class IVa Dispersion-Unshifted Single-Mode Optical Fibers with Low Water Peak
TIA TIA-492E000        EN-Sectional Specification for Class IVd Nonzero-Dispersion Single-Mode Optical Fibers for the 1550 nm Window
TIA TIA-492EA00        EN-Blank Detail Specification for Class IVd Nonzero-Dispersion Single-Mode Optical Fiber for the 1550 nm Window

TIA TR-42 specifies singlemode fiber optic cable for premises applications. OS1 or OS2 fiber for outdoor or indoor/outdoor applications is specified for a maximum attenuation of 0.5 dB/km at either 1310 05 1550 nm. For indoor applications, OS1 or OS2 fiber is specified for a maximum attenuation of 1.0 dB/km at either 1310 05 1550 nm.

Multimode optical fiber IEC, ISO/IEC and TIA cross reference

Description	ISO/IEC 11801-1:2017	IEC 60793-2-10:2019	TIA
50-μm core diameter/125-μm cladding diameter graded-index multimode optical fibers	OM2	A1-OM2 (Formerly A1a.1)	492AAAF (Formerly 492AAAB)
850-nm laser-optimized, 50-μm core diameter/125-μm cladding diameter graded- index multimode	OM3	A1-OM3 (Formerly Type A1a.2 )	492AAAF (Formerly 492AAAC)
850-nm laser-optimized, 50-μm core diameter/125-μm cladding diameter graded- index multimode optical fibers suitable for manufacturing OM4 cabled optical fiber	OM4	A1-OM4 (Formerly Type A1a.3)	492AAAF (Formerly 492AAAD)
50-μm core diameter/125-μm cladding diameter graded-index multimode optical fibers with laser-optimized bandwidth characteristics specified for wavelength division multiplexing	OM5	A1-OM5 (Formerly Type A1a.4 )	492AAAF (Formerly 492AAAE)
62.5-μm core diameter/125-μm cladding diameter graded-index multimode optical fibers	OM1	A1-OM1 (Formerly A1b )	492AAAF (Formerly 492AAAA)
100-μm core diameter/140-μm cladding diameter graded-index multimode optical fibers	NA	A1d	NA

ITU-T had all multimode fibers under G.651.1

100/140 micron fiber is a early multimode fiber optimized for LED sources and low speeds. Another similar fiber was 85/125 microns.

OM1 is legacy 62.5/125 micron multimode fiber standardized for data by IBM in the mid 1980s, adopted by FDDI in the late 1980s and standardized for TIA-568 in the early versions of the premises cabling standard.

OM2 is legacy 50/125 micron multimode fiber standardized for data for gigabit multimode networks in the late 1990s in TIA-568.

OM3 and OM4 are higher bandwidth versions of 50/125 fiber used for faster data networks and for longer distance links.

OM5 is a wideband 50/125 micron multimode fiber standardized for use with short wavelength WDM with VCSEL sources in the range of 850-950nm.

Here is more information on the nomenclature and use of multimode fibers.

Color Codes

Fiber types are identified by color codes for cable jackets and/or connectors.

More information on fiber optic color codes.

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