2014年5月21日星期三

What Is Singlemode and Multimode Optical Fiber?

Light is an electromagnetic wave (visible light frequencies in the order of 10 ^ 14), singlemode fiber and multi-mode fiber optics are needed to explain fluctuations. The basic formula is the electromagnetic theory of Maxwell's equations, the boundary conditions of Fiber Optic Cables (size, refractive index, wavelength and other parameters) into Maxwell's equations.

multimode fiber optic

The solution obtained contains numerous real and imaginary part, representing the spatial distribution of the electromagnetic field and the transmission, each solution can be called a mode, the real part can be interpreted as conductive portion for satisfied the total reflection conditions, it can be called the conduction mode. the imaginary part is rapid loss in the transmission swap, known as radiation modes. The solution with the fiber size, fiber core and cladding refractive index, the wavelength dependence of the incident light. When the fiber core size decreases, the mold can be found rapidly reduced conduction, in particular core size and wavelength may be compared, the conductivity is reduced to the mode field distribution is also a space appears discontinuous, showing the geometrical optics can not be explained. "quantum properties. "When reducing the fiber core size to a certain number, the only one possible conduction mode, this time, the optical fiber for this incident became a single-mode fiber.

Single Mode Fiber
 
Single Mode Fiber Patch Cable is relative, when the wavelength of the incident light is reduced, there will be a new conduction mode, this is relatively light, Fiber has become multimode fiber. So there is a cutoff wavelength of a single-mode fiber that is higher than this wavelength, which is the single-mode fiber. G 652 common singlemode fiber cutoff wavelength less than 1260nm.

Multimode Fiber Optic Cable can be understood as approximately the incident light along many different paths in the optical fiber transmission angles. Clearly different from the other end along the length of the different paths, because the length of the transmission time difference generated by different known mode dispersion (i.e. different paths in different modes).

Single mode optical fiber can transmit along a path (ie, only one mode), there is no mode dispersion. But with different refractive indices in different wavelengths of light in the same material, resulting in different transmission rate, so if the same beam of light contains different frequencies, the other end to the optical fiber transmission time is different, this causes the transmission time difference is called Single-mode dispersion or material dispersion or wavelength dispersive. Not the kind of light source is entirely monochromatic, the wavelength dispersion is widespread. We usually use several sources of communication, the wavelength dispersion smaller than the mode dispersion.

Common single-mode fiber (G 652) is about 8-10um core diameter, the related proudcts from Fiberstore, it's Duplex 9/125 sc to sc fiber patch cord. The picture is follow:

 sc-sc singlemode fiber optic cable

Sc to Sc Fiber Patch Cord is for high bandwidth and transmission rates over longer distances. This SC fiber patch cable is specifically designed for gigabit ethernet applications. The patented injection molding process provides each connection greater durability in resisting pulls, strains and impacts from cabling installs. Common multimode fiber core diameter, there are two types, 50um and 62.5um. The related products from Fiberstore, it's Duplex OM1 Multimode 62.5/125 Lc-Sc Fiber Patch Cable. The picture is follow:

sc to lc multimode fiber patch cable
Article Source From:http://www.cables-solutions.com

没有评论:

发表评论