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1、联系人：孙宇 13714800771,Welcome!,联系人：孙宇 13714800771,ShenZhen BEST OPTO.,深圳市佰思特光电技术有限公司,光电器件,撰写人：郑良桃 2005.3.22,联系人：孙宇 13714800771,Fabry-Perot Laser (FP)Distributed Feedback Laser (DFB)Light Emitting Diode (LED)Vertical Cavity Surface-Emitting Laser (VCSEL) Photo Diode (PD)Pin-Transimpedance (PIN-TIA)Trans
2、ceiver,Abstract,联系人：孙宇 13714800771,2. Fabry-Perot Laser (FP),ApplicationsATM SONET/SDH Fiber Channel,785 nm to 1550 nm. ATM and SONET/SDH applications operate at 1310 nm Moderate cost Edge-emitting device Operate in “closed loop” mode Moderate spectral width Threshold currents can range from 5mA to
3、30mA at room temperature High speed (depending on design) can be used at data rates from 155 Mbps to 2.5 Gbps,联系人：孙宇 13714800771,Output current (bias plus modulation) must remain above the laser threshold current to avoid turn-on delay and optimize speed Can be used for distances to 40 km or longer
4、Threshold current and slope efficiency vary significantly over temperature. Therefore, automatic power control (closed loop) is used to maintain a constant average power (using a monitor diode) and some form of temperature compensation is generally used for the modulation current Eye safety is not a
5、s big an issue with 1310 nm devices, but becomes important with short-wavelength devices (such as 785 nm),联系人：孙宇 13714800771,3. Distributed Feedback Laser (DFB),ApplicationsATM SONET/SDH Fiber Channel DWDM 10 Gbps,1310 or 1550 nm. WDM applications operate at separate wavelengths around 1550nm High c
6、ost Edge-emitting device Operate in “closed loop” mode, Sometimes with TE coolers Internal Bragg grating results in very narrow spectral width (SLM) Threshold currents can range from 5mA to 30mA at room temperature High speed (depending on design) can be used at data rates from 155 Mbps to 2.5 Gbps,
7、联系人：孙宇 13714800771,Used for longer distance (20km to 100km) / high data rate transmission Threshold current and slope efficiency vary significantly over temperature. Therefore, automatic power control (closed loop) is used to maintain a constant average power (using a monitor diode) and some form of
8、 temperature compensation is generally used for the modulation current DWDM lasers require accurate temperature stabilization and therefore contain T/E cooler, thermistor, laser and wavelength locker.,联系人：孙宇 13714800771,4. Light Emitting Diode (LED),Applications FDDI 125 Mbps 100 Mbps Ethernet ATM 1
9、55 Mbps 266 Mbps Fibre Channel Plastic Fiber,820 nm to 1320 nm, though most applications use 850 nm devices Very low cost Large beam divergence angle Operate in “open loop” mode Works across multiple data rates Low coupled output power (usually 20 to -14 dBm) High drive current (usually 60-100 mA),联
10、系人：孙宇 13714800771,Lower speed (typically used at less than 300 Mbps)Higher capacitanceLarge spectral widthDevice speed, output power, and spectral width limit the applications to lower-speed (typically 300 Mbps) data rates at distances generally less than 2km,联系人：孙宇 13714800771,5. Vertical Cavity Su
11、rface Emitting Laser (VCSEL),ApplicationsParallel Arrays Gigabit Ethernet/10GbE Fiber Channel,Short wavelength (850 nm), although long wavelength are in development Low cost, High reliability,联系人：孙宇 13714800771,Surface emitting device (high yield can be optically tested before dicing) narrow spectra
12、l width (can be SLM) Very low threshold current (10 Gbps Output current (bias plus modulation) must remain above the laser threshold current to avoid turn-on delay and optimize speed Some device exhibit a behavior called “off-state bounce” which can result in slower fall times VCSELs (Vertical Cavit
13、y Surface-Emitting Lasers) include geometries, circular output beams, high fiber optic coupling efficiencies, extremely low power consumption, and high modulation rates.,联系人：孙宇 13714800771,Threshold current varies much less on a VCSEL than an edge-emitting (FP or DFB) laser. However, automatic power
14、 control is still used to maintain a constant average power (using a monitor diode) and some form of temperature compensation is generally used for the modulation current. Eye safety is an issue with 850 nm wavelengths. Therefore, safety circuitry is required in the driver for most applications in o
15、rder to maintain eye safety - even with a single-point fault. Open loop operation is possible with some VCSELs, but maintaining eye safety is more difficult.,联系人：孙宇 13714800771,6. Laser Diode Characteristics,Power at 1/ Power at 0 = Extinction Ratio,Automatic Power Control to control average powerTemperature Compensation for modulation,Laser Characteristic,联系人：孙宇 13714800771,MM,FP,DFB,RMS,Center Wavelength,联系人：孙宇 13714800771,7. PhotoDiode (PD),PD Parameter,Sensitivity Sen VR=1V,1310nm 0.80 0.90 A/W,VR=1V,1550nm 0.85 0.90 A/W,
