loading一、画图 Drawing
1. Please draw out the basic setup for an automatic-repeat-request(ARQ) error-correction
scheme
2. Please draw out the fundamental concept of a coherent lightwave system 相干光系统的基本原理图
3. Please draw out the general heterodyne receiver configurations. (a)Synchronous detection uses a carrier-recovery circuit (b)Asynchronous detection uses a one-bit delay line
一般的外差接收机结构(a)使用载波恢复电路的同步检测(b)使用1比特延迟线的异步检测
4. Please draw out the basic constituents of a generic RF--over--fiber link 光载射频系统的基本框图
5. Please draw out the configurations of an EDFA:(a)codirectional
pumping,(b)counterdirectional pumping(c)dual pumping EDFA 三种结构(a)前向泵浦(b)后向泵浦(c)双向泵浦
6. Please draw out a simple 4*4 optical crossconnect architecture using optical space switches
and wavelength converters
使用光空分交换和波长交换的4*4光交叉连接结构
7. Please draw out the components of a typical WDM link 典型WDM链路的构成
8. Please draw out the components of the intensity modulated digital optical receiver 强度调制数字光接收机的方框图
9. Please draw out the generic configuration of a large SONET or SDH network consisting of
linear chains and various types of interconnected rings
10. Please draw out the schematic diagram of NNI position in the SDH network
二、计算题
1、2利用NA、归一化频率求总模数 3、4求耦合损耗 5求信噪比 6求入射光功率 7求SOA的泵浦功率和零信号增益 8 EDFA的功率 9/10 求其模式色散??及传输容量
V2M??7292BL 11、12带宽距离积 13、14系统设计
1. Suppose we have a multimode step--index optical fiber that has a core radius of 25um，a core
index of 1.48，and an index difference △ = 0.01. What are the number of modes in the fiber at wavelengths 860，1310，and1550?m ? Solution：
212?aV??22222M???n1?n2?(a)First, from NA ? A ? （ n 1 ? n 2 ） ? ? and ? n sinn 1 22???212?? at an operating wavelength of 860nm the value of V is
V?2?a?n12??2??25?m?1.482?0.010.86?m =38.2
1?2?a?22V2M???n?n2?Using 2???122??the total number of modes at 860nm is
V2M? ?7292(b)Similarly,at 1310nm we have V = 25.1 and M = 315.