FTTH Fiber Optic Grating Reflectors
Fiber optic reflectors are used for optical network maintenance. They can be installed at the end of an FTTH connection to reflect certain wavelengths of light and transmit all others, which can quickly detect network faults.
The durability of a fiber Bragg grating strongly depends on the material and ftth-optical-grating-reflectors details of grating fabrication. Gratings may be chirped to achieve a desired reflection spectrum.
OTDR Reflector
An optical time domain reflectometer (OTDR) is a specialized instrument that uses a pulse of high-power light to characterize an optical fiber. It injects light into the fiber and extracts, over a period of time, back-scattered and reflected light to measure the strength of the pulse and its distribution along the fiber. The OTDR can then determine the location of events such as connectors, mechanical splices, bulkheads and breaks in the fiber. It can also locate and determine the loss of sections of the fiber, splice losses, gainers, roll-offs and other factors that affect fiber performance.
One type of reflection that the OTDR can detect is known as Fresnel reflection, which is caused by an abrupt change in index of refraction in the fiber. These events can cause a spike in the OTDR trace, which can be detected by the OTDR software. The OTDR then distinguishes these events from echoes that can occur within the fiber itself, which do not exhibit losses.
Another important specification is the event dead zone, which refers to the minimum distance from a reflective event that the OTDR can accurately detect and resolve. This is because the detector in an OTDR can become saturated for a short amount of time after a strong reflective event, similar to how your eyes recover from being blinded by a bright car headlight.
FBG Reflector
The FBG reflector is an optical passive device that uses a short segment of fiber Bragg grating to reflect certain wavelengths and transmit other wavelengths with little attenuation. This can realize online rapid fault detection of optical fiber lines without affecting the normal communication of other signals in the network.
The reflected light signal has the same wavelength as the input one at the point where a periodic change of refractive index occurs on the grating. When the grating period is approximately half the input signal’s wavelength, all the reflected signals combine coherently to form one large reflection at a specific wavelength. The wavelength at which this happens is called the Bragg wavelength. The FBG reflector is mainly used for FTTH maintenance, such as PON OTDR test, central computer room reflectivity test, communication system link detection.
In addition, the FBG reflector can also be used for a wide variety of applications such as civil health monitoring, strain and temperature sensors in composite materials for aircraft structures, etc. By indoor-duplex-fiber-optic-cables exploiting the influence of temperature or strain on the characteristics of the gratings, we can obtain different spectral responses for these FBG sensors.
These sensors are typically fabricated by applying UV radiation to the surface of an irradiated asymmetrical multimode optical fiber. The Bragg wavelength and bandwidth, grating period, grating length and reflectivity of an FBG can be accurately controlled in fabrication.
FBG Adapter
The FBG adapter is a component used for testing P2P optical lines. It is a standard SC/LC connector structure that packages a special FBG in its ferrule. The FBG filter is designed to reflect certain wavelengths, making it easy for the OTDR to detect the fiber connection. It also allows the OTDR to quickly and accurately check whether the line is normal or not.
The OTDR can use the FBG identifier to determine whether the line is normal or not by looking at the reflection of the test pulses. The identifier can then detect any defects in the optical transmission system, and keep track of the line’s health in real time. This makes it easier to maintain the network.
The FBG identifier is an excellent choice for P2P optical networks. It can be used in central offices or at the OTO (Optical Termination Outlet). It uses a coding written directly into the FBG to identify the connection in the fibre. This makes it very easy to locate the fault and solve problems quickly. In addition, it does not interfere with the standard P2P wavelengths used in telecommunications. It is a great option for testing P2P optical transmission systems. Diamond can offer a variety of adapter solutions to meet your needs. These adapters can be customized to meet the specific mechanical and optical requirements of your project.
FBG Pigtail
Long period grating couple light from a guided mode into forward propagating cladding modes where it is lost due to absorption and scattering. This loss is wavelength dependent and it can be used to control the mode-coupling ratio. In addition, the grating can be designed to have different reflection properties over a range of wavelengths. This makes them ideal for use in DWDM systems.
The FBG pigtail is installed in the front end of ONU (Optical Network Unit). Combined with the OTDR equipment, it can help to increase the sensitivity of the OTDR and effectively reflect the test signal on the OLT side, while the normal traffic signal of PON system will pass through with little attenuation. This enables the quick and accurate detection of fault points on the optical fiber and can improve the efficiency of network maintenance.
The pigtail is easy to install in the optical connectors and connects with the standard adapters by inserting them in place. Its alumina ferrule is partially encapsulated in the ceramic ferrule and has good dirt resistance. It is available in different styles based on pigtail connector type including Lucent Connector (LC) and Square Connector (SC). The pigtail can be supplied with either single-mode or multimode fiber optics, and it can be customized to meet the specific requirements of customers.