Category Archives: OTDR

Overcome OTDR Dead Zone With Launch Fiber

OTDR is a popular fiber optic testing tool which can be used to test the fiber loss, and locate the faults in fiber optic links. However, the OTDR dead zone will affect the testing result and the application of OTDR. To overcome OTDR dead zone during fiber optic testing, launch fiber is being added between OTDR and optical fiber link under test. OTDR launch fiber comes in different types of packages. OTDR launch box and OTDR launch fiber ring are the most commonly used launch fibers.

Why Can Launch Fiber Overcome OTDR Dead Zone?

OTDR insert pulses of light into fiber optic link and measure the back reflection caused by fiber faults to locate the faults. If a long fiber link is required to be tested, a lot of optical power should be inserted into the optical fiber to make sure that the light can be seen at the other end. If powerful optical pulses are inserted into optical fiber, pulse width of the launched optical signal will be increased, which will cause the dead zone at a length of fiber and affect the testing result of OTDR. This dead zone might be hundreds or thousands meters long.

OTDR launch box

To minimize the affection of the OTDR dead zone during fiber optic testing. A length of long enough optical fiber is being added between the OTDR and the fiber under test. In this way, the OTDR dead zone will happen in this additional optical fiber. The launch fiber is actually a length of optical fiber which is long enough to cover the OTDR dead zone to increase the testing accuracy. Launch fiber is usually terminated with a connector on each end to connect the OTDR with the fiber link under test.

launch fiber

OTDR Test With Launch Fiber

OTDR launch fiber mainly has two designs, one is fiber ring design and the other is box design, separately known as launch fiber ring and OTDR launch box or OTDR dead zone box. The using of them is generally the same. Here offer two situations about how to use OTDR launch fiber.

OTDR testing with launch fiber

In some cables, launch cable is being used to cover the dead zone at the beginning of the fiber link. In these cases, OTDR launch fiber or OTDR launch box is deployed between the OTDR and the near end connection as shown in the above picture. This allows the accurate measurement of the fiber loss at the near end connection.

OTDR and launch fiber

In some cases, the fiber loss at the far end connection should also be tested. Then, the launch fiber can be installed added at the far end connection to work as a receive cable, as shown in the above picture.

Please note that the launch fiber you used for testing should have the same fiber types (OS2, OM1, OM2, OM3, OM4) as the optical fiber under test.


Using launch fiber to overcome OTDR dead zone is the choice in most cases, especially for long optical fiber testing. Let the OTDR dead zone occur in the launch cable to ensure the accurate testing result. Launch fiber is suggested to be added at the beginning and the end of the fiber optic link, if the light loss of the whole fiber link is required. If you want to need more specific details about OTDR launch box, kindly visit another article: Why Do You Need OTDR Launch Box

YOKOGAWA AQ1200 MFT-ODTR Handheld Optical Fiber Test Tool Operating Guide

Fiberstore is specialized in supplying fiber optic components and network equipment. Famous YOKOGAWA AQ series ODTR is also on sale in Fiberstore. In this article we will introduce AQ1200 handheld OTDR(Figure 1.) which is the newest addition to Yokogawa’s OTDR product family offering an even smaller and lighter alternative to the AQ7275 models. The AQ1200A (1310/1550nm) is a standard model with the same wavelengths used for communication services. Some of AQ1200’s basic functions and operating notes will be decribed in this paper.

Figure 1. YOKOGAWA AQ1200 MFT-ODTR Handheld Optical Fiber Test Tool

Operating Guide
Checking the package first
After receiving your oderd AQ1200 MFT-ODTR Handheld Optical Fiber Test Tool from Fiberstore, you may check out the pacakage items as the Figure 2. . If the wrong items have been delivered, if items are missing, or if there is a problem with the appearance of the items, contact Fiberstore as soon as possible.
YOKOGAWA AQ1200 MFT-OTDR Handheld Optical Fiber Test Tool

Figure 2. Package of AQ1200 MFT-ODTR Handheld Optical Fiber Test Tool

Safety Precautions
Everyone who use AQ1200 must comply with the safety precautions. If instrument is impaired by being used in a manner not specified in the safety precautions, Fiberstore assumes no liability for the customer’s failure to comply with these requirements.

Following symbols are used on AQ1200 handheld OTDR


  • Make sure that the power supply voltage matches the AC adapter’s rated supply voltage and that it does not exceed the maximum voltage range specified for the power cord;
  • Only use the power cord and AC adapter that were included with the AQ1200;
  • Only use the AQ1200 battery pack;
  • Do not look directly or indirectly into the laser beam or at a specular reflection of the beam without protective equipment;
  • Do Not Operate in an Explosive Atmosphere;
  • Do Not Remove Covers.

Names and Functions of Parts
AQ1200 MFT-ODTR Handheld Optical Fiber Test Toola is a compact and lightweight handheld OTDR with functionality optimized for the installation and maintenance of optical fiber cables and equipped with functions and operability that make the field testing easier. Names and Functions of parts will be clearly decribed in Figure 3. and Figure 4..

Figure 3. Names and Functions of Parts 1


Figure 4. Names and Functions of Parts 2


  • Loss Testing
  • Visible light source
  • Fault Locator
  • Checking Fiber End Faces
  • IP Testing
  • PON power meter
  • Multi-Core Fiber Measurement

Why choose Fiberstore?
Same brand, same quality, same warrenty, why not choose the cheaper one? This is the directly answer why choose Fiberstore as your YOKOGAWA AQ1200 MFT-ODTR Handheld Optical Fiber Test Tool supplier.

Fiberstore supplys OTDR of famous brands except YOKOGAWA AQ series, such as JDSU MTS series, EXFO FTB series and so on. In addition, OEM portable and handheld OTDRs (manufactured by Fiberstore) are also available. All OTDRs are saled with a very reasonable price and warrenty for one year. Want to know more, welcome to our website:

Cisco Leads 100G Ethernet Switch Market

In first quarter of 2013, the worldwide Ethernet switch market was $ 4.7 billion, decreased by 8% compared with 2012Q4, but an increase of 1%. 40G is the only port shipment growth products, an increase of 2%, which was mainly due to 40G fixed switches (such as 16xQSFP+) and chassis-based switches 40G line cards. Cisco is the early leader in 100G Ethernet switch port.

Due to the influence of seasonal factors, in first quarter of 2013, the Ethernet switch sales fell, but the past three quarters, the overall is still increased, taking into account the continued weakness in Europe and the U.S. federal government expense decreased , this is a positive signal.

In first quarter of 2013, port shipments fell 4%. 10G, which is generally considered as a star product, the chain fell highest.

40G is the only port shipment growth products, an increase of 2%, which was mainly due to 40G fixed switches (such as 16xQSFP +) and chassis-based switches 40G line cards.

Almost all of the Ethernet switch equipment manufacturers on a quarter-on-quarter drop.

Cisco is the early leader in 100G Ethernet switch port.

The Biggest Ratio eOTDR Prototype

Huawei announced that they have successfully developed the industry’s largest spectral built-in optical time domain reflection tester, which maximum support is 1:64, through the network simulation, its precision is up to 5 meters. The technique breakthrough marked the eOTDR technology has reached FTTHPON network commercial networking requirements.

Embedded Optical Time Domain Reflectometer, which is short for eOTDR. It’s the utilization of scattering light in optical fiber transmission and precision instrument, is mainly used for optical fiber quality detection and fault location, etc. Traditional external OTDR test system in PON FTTH network maintenance and fault detection, the need to change the ODN physical optical fiber connection, the system has high cost, difficult to implement.

With the development of FTTx, optical fiber developed quickly. Operators increase investments for fiber optic network year by year. How to manage cables management quickly and efficiently, to reduce OPEX, become the urgent demand of operators FTTx network construction.

Huawei eOTDR prototype through the built-in OTDR in OLTPON optical module, which can judge the fiber’s physical connection. At the same time, the built-in OTDR module and ordinary optical module size is consistent. Operators will place ordinary optical module with built-in OTDR optical module, but can not change the FTTx fiber physical network, also do not need ONT extra coordinate positioning, to avoid the external engineering of OTDR test, shorten the time needed for a fiber fault location, reduce the fiber optic fault management costs.

The industry mainstream manufacturers provide 1:8 eOTDR product ratio, after many years of technical research and experimental verification, the breakthrough to develop the  1:64 eOTDR prototype, covering the mainstream of FTTH patch cables construction scene, marked the eOTDR technology realized, breakthroughs from lab scale to commercial technological.