Single-mode optical fiber

Single-mode optical fiber glass: center core very fine (core diameter is generally 9 or 10 mu m), can pass a pattern of light. Therefore, its mode between dispersion small, for remote communication, but also exists material dispersion and waveguide dispersion, such single-mode optical fiber of illuminant spectrum width stability have higher demand, namely spectrum width to narrow, better stability. Later found in 1.31 muon m wavelengths, single-mode optical fiber material dispersion and waveguide is, a dispersion a negative, the size also just equal. So, 1.31 muon m wavelength area became optical fiber communication of a very ideal job window, is now practical optical fiber communication system's main job band 1.31 muon m conventional single-mode optical fiber is the main parameters by the international telecommunication union (ITU - G652 proposals in T sure, so the optical fiber G652 say again.

Fiber introduction

"Single-mode optical fiber" in the academic literature of explanation: general v less than 2.405, optical fiber in only one wave through the so called the single-mode optical fiber, it's very fine, about 3 a 10 micron, modal dispersion small. Influence of bandwidth optical fiber preach John is the main factor is all sorts of dispersion, and with the modal dispersion is most important, single-mode optical fiber dispersion small, so the light with wide band transmission for long distances.

Single-mode optical fiber has 10 micron of core diameter can allow single-mode beam transmission, but minus bandwidth and vibration mode dispersion (Modal dispersion) limit, but due to the single-mode optical fiber core diameter is too small, difficult to control the beam propagation, so it needs to very expensive laser as the sources body, and single-mode optical cable of the primary limitations Material dispersion (Material dispersion), single-mode optical cable mainly using laser to obtain high frequency width, and because LED will be sent a lot of different frequency width lightsource so Material dispersion requirement is very important.

Single-mode optical fiber than multimode fiber can support longer distances, in this line 100MBPS Ethernet and 1G gigabit nets, single-mode optical fiber can be supported by over the transmission distance boasting.

From the cost Angle consideration, by YuGuangDuan machine is very expensive, so the cost of using single-mode optical fiber than multimode fiber cable high costs.

Single-mode optical Fiber (SMF Fiber, performance? Mode)

Refractive index distribution and mutation fiber-optic similar, fiber core diameter only 8 ~ 10 mu m, the light in a straight line shape along the fiber core center axis direction spread. Because of this kind of optical fiber transmit only one mode (two polarization Jane and), so called single-mode optical fiber, the signal distortion is small.

Fiber classification

G. 652 single-mode optical fiber

Meet the requirement of itu-t T.G. 652 single-mode optical fiber, commonly called the dispersion displacement of optical fiber, the zero dispersion in 130 um window low loss area, operating wavelength for 1310nm (loss as 0.36 dB/km). Our country has the fiber optic cable laying most single-mode optical fiber and multimode fiber

Is this kind of optical fiber. With optical fiber &cable industry and semiconductor laser technology, optical fiber links successfully promote wavelength can be transferred to the work more low loss (leel dB/km) 1550nm fiber window.

G. 653 single-mode optical fiber

Meet the requirement of itu-t T.G. 653 single-mode optical Fiber, often say Dispersion displacement Fiber (Fiber Dispersion Shifled DSF =), the zero Dispersion wavelengths shift to a very low loss 1550nm place. This kind of optical fiber in some countries, especially in Japan, China was popularize the use of jingjiu trunk lines will be adopted. American AT&T found early DSF seriously insufficient, in 1550nm near low dispersionregion existing harmful four-wave mixing optical frequency etc, obstruct fiber amplifier nonlinear effects in the application of 1550nm window. But in Japan, will the dispersion compensation technology * for g. 653 single-mode optical fiber lines, still can solve the problem, but did not see any Japanese g. 665 fiber, as of a mystery.

G. 665 single-mode optical fiber

Meet the requirement of itu-t T.G. 665 single-mode optical Fiber, often say the zero Dispersion displacement optical or NZDSF (= NonZero Shifted Fiber Dispersion). Belong to dispersion displacement, but in 1550nm place fiber dispersion is not zero (by itu-t T.G. 665 regulation, 1565nm 1530 - in wavelength range corresponding dispersion value equal to 0.1-6.0 ps/nm * km), to balance four-wave mixing frequency etc nonlinear effects. Commodity fiber as AT&T's TrueWave fiber, Corning SMF - the LS fiber (the zero dispersion wavelengths typical values for 1567.5 nm, zero dispersion typical values 0.07 ps/nm2 *