Fiber Optic Reflector

Fiber optic reflector is a compact device that reflects a special wavelength while passing through all other wavelengths. It is used to detect any link problem in the PON system. Usually, the special wavelength is a test wavelength, which is not in the range of the working wavelength. It makes the test to find the problem will not affect the normal links.

As we know, the OTDR can be used to detect the link where is damaged or broken. But when the light signal is split into several parts(splitter is used in the FTTH network), only OTDR is not enough to solve the problem since it is difficult to measure the reflection and attenuation of split signal and find the link damage position through echo delay. In this case, OTDR + fiber optic reflector system is a good solution. OTDR measure the reflect wavelength and compare the retrun loss between the fault link and normal link, in this way it can not find the accurate position where is damaged, but it can find which fiber is broken or damaged. Normally we just need replace the damaged fiber with a new one then can solve the problem.

The workflow as below:

According to the working mechanism, there are two types:

1. FBG fiber optic reflector

The fiber material is photosensitive, the incident light coherent field pattern can be written into the core of the fiber through exposure to ultraviolet light, it makes the refractive index of the core axis change periodically, then form a spatial phase grating. It functions as a narrow band filter in the core. When a beam of broad-spectrum light passes through the fiber grating, the wavelength which meets the Bragg condition of the fiber grating will reflect, and the rest of the wavelengths will pass through the fiber grating.

2. Dielectric film reflector

The dielectric film reflector can be pre-installed in the connector or adapter. It will change the physical structure of the connector/adapter.

Anfkom provides different types of fiber optic reflector, such as SC Female-Male type, LC Female-Male type, FC Female-Male type, pigtail type.