Optical module and optical fiber connector application guide

One, the optical transceiver module definition The optical transceiver module is composed of optoelectronic devices, circuits and optical interface components, optoelectronic device includes transmitting and receiving the two part. Transmitting part is: input a certain rate of the signal through the internal drive chip processing after driving a semiconductor laser ( LD ) or a light emitting diode ( LED ) emitted from corresponding rate modulated optical signal, its interior with automatic optical power control circuit, the output power of the optical signal to maintain the stability of. The receiving part is: a certain rate optical signal input module by the light detecting diode is converted to electrical signals. The preamplifier output corresponding rate signal, the output signal is generally PECL level. At the same time in the input optical power is less than a certain value will output a warning signal. In two, the optical transceiver module classification In accordance with the rate: Ethernet 100Base ( 100m ), 1000Base ( GPA), 10GE Application of SDH 155M, 622M, 2.5G, 10G In accordance with the package : 1× 9, SFF, SFP, GBIC, XENPAK, XFP, a variety of packaging. 1 x 9 package -- welding type optical module, the general speed of not more than thousand, use SC interface The SFF package­-- welding small packaged optical module, the general speed of not more than thousand, use LC interface The GBIC package -- hot pluggable Gigabit interface optical module, using SC interface The SFP package -- hot plugging of small package module, the highest rate of up to 4G, using LC interface The XENPAK package -- Application in Gigabit Ethernet, using SC interface XFP -- 10G optical module package, available in Gigabit Ethernet, SONET and other systems, uses the LC interface According to the laser types: LED, VCSEL, FP LD, DFB LD In accordance with the emission wavelength: 850nm, 1310nm, 1550nm etc. According to the using modes: non hot-plug ( 1 ×9, SFF ), hot pluggable ( GBIC, SFP, XENPAK, XFP ) In three, a fiber optic connector classification and main specifications and parameters Optical fiber connector is in a section of the fiber ends are mounted on the connecting head, mainly for the use of light distribution. According to fiber type: single mode optical fiber connector ( usually G.652 fiber optical fiber diameter: 9um, diameter 125um), multimode optical fiber connector According to the optical fiber connector is connected to the head form: FC, SC, ST, LC, MU, MTRJ and so on, the current commonly used with FC, SC, ST, LC, Type FC -- the earliest by Japan NTT development. External reinforcement using metal sleeve, fastening means for turnbuckles. Test equipment selection of the joint more. Type SC -- from the development of Japanese NTT company molded plug coupling connector. Its shell with molding with a mold made of plastic, glass fiber, is rectangular; pin by precision made of ceramic, metal slotted sleeve coupling sleeve structure. The fastening way adopts plug pin type, does not require rotation. Type LC -- company's design. The outer diameter of the sleeve is 1.25mm, are usually used in FC-SC, ST 2.5mm half casing outside diameter. Improved application of density. According to the optical fiber connector head pin end points: PC, SPC, UPC, APC According to the optical fiber connector: diameterΦ 3,φ2,φ0.9 Optic fiber connector mainly optical properties, mechanical properties, interchangeability, environmental performance and life. The most important of which is the insertion loss and return loss of the two indicators. In 1, the optical module transmission rate: fast, Gigabit Ethernet, 10GE etc. In 2, the optical module transmitting optical power and receiver sensitivity: transmitting optical power refers to the transmitting terminal of the light intensity, receiving sensitivity can detect the intensity of light. Both in dBm as a unit, is the effect of the transmission distance is an important parameter. The optical module can transmit distance mainly by loss and dispersion two limited. Loss limit according to the formula: loss restricted distance = ( transmitting optical power - receiving sensitivity ) / optical fiber attenuation to estimate. Optical fiber attenuation and the actual selection of optical fiber. The general current G.652 fiber can achieve 1310nm band 0.5dB/km, 1550nm band 0.3dB/km even better. 50um multimode optical fiber in 850nm band 4dB/km 1310nm band 2dB/km. For fast, gigabit optical module dispersion Limited far outweigh the loss is limited, can not be considered. In 3, 10GE optical module according to 802.3ae standard, the transmission distance and the selection of optical fiber type, Hikarumo Hikaru performance. 4, saturated optical power values of light module receiving end maximum detectable optical power, generally -3dBm. When the received optical power greater than the saturation power time can also lead to error code generation. So the emission light power laser module without attenuation loopback test error phenomenon will appear. In five, the optical module failure reason The optical module failure for transmitting end and receiving end failure analysis failure, the specific reasons, most often a problem focused on the following several aspects: 1 of light pollution and damage Due to the pollution and damage caused by the optical interface of optical link loss becomes larger, resulting in optical link. The reasons are: A. optical module, light exposure in the environment of light pollution, dust entering; B. use of optical fiber connector end face have pollution, light pollution two optical module; C. pigtail optical connector end face used improperly, surface scratch; D. use inferior optical fiber connector;