<![CDATA[SINARAN OPTIK SDN BHD - Fiber Optics Blog]]>

<![CDATA[SINARAN OPTIK SDN BHD - Fiber Optics Blog]]>Thu, 14 May 2026 22:02:35 +0800Weebly<![CDATA[Testing & Commissioning Optical Fiber Link -Part 2]]>Fri, 06 Jan 2017 04:03:02 GMThttps://www.sinaranoptik.com/fiber-optics-blog/testing-commissioning-optical-fiber-link-part-2Testing & Commissioning Optical Fiber Link -Part 1 HERE

More Examples on Calculation of Optical Power Budget

Assuming our Multimode Fiber Optics cabling configuration as below :

As per Singlemode, there are 2 common operating wavelength namely 850nm and 1300nm.
The respective attenuation or loss as illustrated below :

Figure 2 : Operating Wavelength Attenuation

Please refer to the following link for calculation of optical fiber budget formula :-
Testing & Commissioning Optical Fiber Link -Part 1 HERE

Optical Power Budget Calculation
Using above Figure 1 fiber optics schematic diagram followings can be deduced :
a. Total length of fiber is 1km (please use OTDR to measure actual fiber length)
b. 2 nos of splicings
c. 2 nos of connectors
d. MM operating wavelength of 850 nm - 3dB/km, 1300nm - 1dB/km

Operating Wavelength at 850nm
Maximum Allowable Loss = Fiber Loss + Splicing Loss + Connector Loss
= (1 km x 3 dB/km) + ( 2 x 0.2dB) + ( 2 x 0.5dB)
= 4.4dB
Operating Wavelength at 1300nm
Maximum Allowable Loss = Fiber Loss + Splicing Loss + Connector Loss
= (1 km x 1 dB/km) + ( 2 x 0.2dB) + ( 2 x 0.5dB)
= 2.4dB

As such, when we do actual measurement using power meter & light source the measured loss must be less than the calculated allowable maximum loss.
If the actual measurement value is higher than calculated maximum loss then most likely there will no communication or transfer data between Station A and Station B.

On next articles we will emphasized on

Calculating budget loss if there are jointings or splicings between fiber optics cable
Calculating budget loss if few fiber optics cable are connected via connectors

]]><![CDATA[Testing & Commissioning Optical Fiber Link -Part 1]]>Wed, 04 Jan 2017 06:25:54 GMThttps://www.sinaranoptik.com/fiber-optics-blog/testing-commissioning-optical-fiber-link-part-1Calculation of Optical Power Budget

What is Optical Power Budget ?

The optical power budget identifies how much attenuation or loss is allowed across a fiber span while still maintaining sufficient output power for the receiver.

Assuming that we are in the planning of installing a singlemode fiber optics cable from point A to point B for our data communication project.
Prior to actual fiber implementation we need to calculate before hand the allowable maximum loss or optical power budget or optical power loss.

Figure 1 : Cabling Schematic Diagram

For Singlemode fiber optics the common operating wavelengths are both 1310nm and 1550nm.
For Multimode fiber optics the common operating wavelengths are both 850nm and 1300nm.
Based upon manufacturers fiber specification, the attenuation or fiber loss at both operating wave length are as follows :

Figure 2 : Fiber attenuation for both SM and MM

How To Calculate Optical Power Budget ?

The Optical Power Budget Loss is equivalent to the total loss of fiber loss + splicing loss + connector loss.
It is illustrated as below :

Figure 3 : Optical Power Budget

Fiber Loss = Length of fiber (km) x Attenuation (dB/km)
Length of fiber (km) - to get this value by using OTDR
Attenuation (dB/km) - SM 1310nm - 0.3dB/km & SM 1550nm - 0.2dB/km
MM 850nm - 3dB/km & MM 1300nm - 1 dB/km

Splicing Loss = No. of splicing x Max splicing loss (dB)
No. of splicing - total number of splicings done from Station A to Station B
Max splicing loss - as per TIA/EIA recommendation 0.2dB for each splicing

Connector Loss = No. of connector x Max connector loss (dB)
No. of connectors - total number of connectors from Station A to Station B
Max connector loss - as per TIA/EIA recommendation 0.75 dB for connectors
(but we take maximum connector loss at 0.5dB)

Optical Power Budget Calculation Example

Using above Figure 1 fiber optics schematic diagram followings can be deduced :
a. Total length of fiber is 1km
b. 2 nos of splicings
c. 2 nos of connectors
d. SM operating wavelength of 1310 nm - 0.3dB/km, 1550nm - 0.2dB/km

Operating Wavelength at 1310nm
Maximum Allowable Loss = Fiber Loss + Splicing Loss + Connector Loss
= (1 km x 0.3 dB/km) + ( 2 x 0.2dB) + ( 2 x 0.5dB)
= 1.7dB

Operating Wavelength at 1550nm
Maximum Allowable Loss = Fiber Loss + Splicing Loss + Connector Loss
= (1 km x 0.2 dB/km) + ( 2 x 0.2dB) + ( 2 x 0.5dB)
= 1.6dB

As such, when we do actual measurement using power meter & light source the measured loss must be less than the calculated allowable maximum loss.
If the actual measurement value is higher than calculated maximum loss then most likely there will no communication or transfer data between Station A and Station B.

On next articles we will emphasized on

More calculated examples schematic diagram
How to measure fiber optics loss using power meter & light source
How to troubleshoot fiber optic link to find the exact causes of higher fiber loss.

]]><![CDATA[Optical Power Loss (Attenuation) - Part 5/5]]>Fri, 30 Dec 2016 15:25:38 GMThttps://www.sinaranoptik.com/fiber-optics-blog/optical-power-loss-attenuation-part-55Read Optical Power Loss (Attenuation) - Part 1/5 HERE
Read Optical Power Loss (Attenuation) - Part 2/5 HERE
Read Optical Power Loss (Attenuation) - Part 3/5 HERE
Read Optical Power Loss (Attenuation) - Part 4/5 HERE

Material Losses due to manufacturing

Rayleigh Scattering

Fresnel Reflection

]]><![CDATA[Optical Power Loss (Attenuation) - Part 4]]>Thu, 22 Dec 2016 13:25:40 GMThttps://www.sinaranoptik.com/fiber-optics-blog/optical-power-loss-attenuation-part-4Read Optical Power Loss (Attenuation) - Part 1 HERE
Read Optical Power Loss (Attenuation) - Part 2 HERE
Read Optical Power Loss (Attenuation) - Part 3 HERE

What is Connectors Loss?

Connector loss in power budget calculation is considered as a pair of connectors being connected into an adapters as shown above diagram.
As per TIA/EIA specification, the maximum loss of paired connector is 0.75dB.
However, during power budget loss calculation we take maximum connector loss as 0.5dB so as to introduce loss buffer.

http://www.fiber-optic-transceiver-module.com/

Main factors that contribute to the fiber optics connector loss are :

dirty or contaminated connector (on the ferrule surface)
damaged fiber optics connectors end ferrule surface
Improper fiber optics installation or being connected - both pair connectors are not properly aligned

Other factors that may contribute to the higher losses are :

mismatched fiber cores
misaligned fiber cores
mismatch index of refraction

Always clean fiber optics connectors and adpaters with proper cleaning solution i.e. isoprophy alcohol
Use connector ferrule end cap to protect against dust and scratches

]]><![CDATA[ Optical Power Loss (Attenuation) - Part 3]]>Wed, 21 Dec 2016 12:11:19 GMThttps://www.sinaranoptik.com/fiber-optics-blog/-optical-power-loss-attenuation-part-3Read Optical Power Loss (Attenuation) - Part 1 HERE
Read Optical Power Loss (Attenuation) - Part 2 HERE

What is Splice Loss?

Splice loss occurs at all splice locations.
Mechanical splices normally have the highest splice loss from 0.2dB to over 1.0dB.
Fusion splices on the other hand have lower losses usually less than 0.1dB or even lower than 0.05dB depending upon type of reliable fusion splicer and an experienced splicing crew.

High splicing loss caused by few number factors. However, most high splicing loss are due to workmanship for example

Poor cleaving - please rotate cleaver blade if you keep getting bad cleaved

There are high splice loss due to manufacturing defects as shown below :

End result of splicing due to fiber misalingment or lateral offset and cladding diameter mismatched - osa.org

Splicing loss

Splicing loss as indicated on the fusion splicing machine is based upon estimation only.
In order to get accurate splicing loss you need to check with OTDR as shown below. You need to obtain splicing loss by shooting OTDR from A to B and from B to A

Assuming the obtained both splice losses are as below :
a. From A to B is -0.04dB
b. From B to A is -0.02dB
Using averaging formula below the final splice loss is -0.03dB

]]><![CDATA[ Optical Power Loss (Attenuation) - Part 2]]>Tue, 20 Dec 2016 13:59:35 GMThttps://www.sinaranoptik.com/fiber-optics-blog/-optical-power-loss-attenuation-part-2Read Optical Power Loss (Attenuation) - Part 1 HERE

What is Bend Loss ?

Bend loss occurs when fiber optics cable bends smaller than recommended fiber cable minimum bending radius or simply stated it is a loss induced by physical stress on fiber optics.

Mininim Bending Radius - Rule of Thumb
a. 10 x outer diameter fiber optic cable when cable at rest
b. 20 x outder diameter fiber optic cable during pulling

Effects of fiber optics bend on fiber optics performance ?
When a fiber cable is bent smaller than minimum bending radius, the optical signal within the cable may refract and escape through the fiber cladding.

Bending can also permanentlsy damage the fiber by causing micro cracks, especially during cable installation when pulling forces are to be expected. The result is known as bend loss: a loss of signal strength that may compromise the integrity of the data transmission.;

This type of fiber optics bend loss is called macrobending which can add up to to a significant to fiber optics performance.

Types of Bend Loss

There are two type of fiber optics bending losses.
a. Macrobending loss
Macrobending loss is referred to loss induced by physical stress inserted into the fiber optics itself.
b. Microbending loss
Microbending loss is caused by imperfection in the fiber optics internal structure might be due to manufacturing process or due to pulling method.

]]><![CDATA[Optical Power Loss (Attenuation) - Part 1]]>Tue, 13 Dec 2016 02:41:19 GMThttps://www.sinaranoptik.com/fiber-optics-blog/optical-power-loss-attenuation-part-1

Light travelling in an optical fiber loses power over distance
Loss of power depends on light wavelength (1310nm,1550nm, 850nm,1300nm)

Decibel (dB) is a unit of measured optical fiber loss
The fiber optics specification loss is expressed in dB/km.
The dB/km loss is multiplied by total length of fiber optics length in order to obtain total loss in dB.

Please check with fiber optic specification sheet as issued by fiber optics manufacturers

Optical fiber losses are categorised into extrinsic and intrinsic losses
Extrinsic losses are due to bending, splice and connector loss
Intrinsic losses are due to fiber optics inherent loss, loss to fabrication and fresnel reflection

]]><![CDATA[Fiber Optics Pulling]]>Wed, 07 Dec 2016 16:41:19 GMThttps://www.sinaranoptik.com/fiber-optics-blog/fiber-optics-pullingIt is has become a norm in telecommunication industry whereby we will see groups of electrical engineers, copper & wireless installers are closely becoming involved with fiber optic installation, termination and testing & commissionning.
Once we fully understand the simple fiber optics guidelines then the process of installation, termination & testing would be easier to handle.

Please use following guideliines in order to secure maximum fiber optics cable performance,
a. Never kink the cable.
b. Never exceed recommended bend radius during or after installation. If during cable pulling the minimum radius is 20 x than the cable outer diameter and 10 x when cable at rest.

c. Do not exceed recommended tensile loads. Use external pulling grips so as the load is applied to the cable strength member and not unto the fiber itself.
e. Monitor tensile loading or pulling force.
f Avoid pulling long lengths in one direction.

f. Do not crush put pressure on the cable.
g. Plan to install extra cable protection in high-risk areas such as HDPE conduit.
h. Always secure cables in all installations over ceilings or under floors.
i. Survey and plan all cable routes in order to protect cable against rodents or external stress or pressure.
j. Comply with all regulatory requirements and fire codes.

]]><![CDATA[What is Power Meter & Light Source Test Gears?]]>Tue, 06 Dec 2016 09:27:22 GMThttps://www.sinaranoptik.com/fiber-optics-blog/what-is-power-meter-light-source-test-gears

Both Light Source and Power Meter are being used to measure the actual fiber optics losses from point A to point B.
The total measuread fiber optics signal lossess included following losses :-
a. Fiber optics loss
b. Splicing loss
c. Connector loss
The measured readings shall be compared with calculated maximum allowable fiber optics loss from point A to point B or link loss budget as per TIA-568 specification.

Should the measured readings is above the calculated maximum loss then troubleshooting steps need to established in order to pinpoint the actual fiber optics components that are giving high losses.
Generally the high losses could be attributed to one or more of the followings problems :-
a. excessive fiber optics bending
b. high loss splicing workmanship
c. dirty connector
d. dirty adapter
e. improper pulling of fiber optics cable

]]><![CDATA[Fiber Optics Connector Cleaner]]>Mon, 05 Dec 2016 14:12:31 GMThttps://www.sinaranoptik.com/fiber-optics-blog/fiber-optics-connector-cleaner

Fiber Optics Connector Cleaner is to clean end surface of connector ferrule from dirt so as to enable smooth light transmission from one connector to the other with lowest possible losses.

Alternatively you can use isoprophyl alcohol and normal cotton facial tissue that is available in any pharmacy stores to clean the end surface of fiber optics connector ferrule.

Always check end ferrule surface after cleaning either by using 100x or 400x microscope.

A good end ferrule surface (the most left photo) will provide a smooth laser transmitted from one connector to the other connector.
Otherwise you may need to repeat the cleaning process or perhaps you need to re-splice or re-terminate with new connector.

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