Detection and Signal Processing: Technical Realization (Springer Series in Advanced Microelectronics)

Thesecondpartdealswithampli?cationproblemsandtherecovery ofrepetitivesignalsburiedinnoise. Thelastpartisdevotedtosolvingthe problemsconnectedwithreachingtheultimatedetectionlimitorquantum limit. Thisisdoneforheterodynedetectionandphotoncounting. Although VIII Preface heterodynedetectionyieldstheultimatesensitivity,itsspatialmodesel- tivityand,ingeneral,thelowspectralpowerdensityofthesignalrequire sophisticatedprovisions. Thisisdiscussedindetail. Theinherentproblemsare analyzedandappropriatetechnicalsolutionsaredescribedtoreachtheul- matesensitivityfordetectingincoherentradiationandcommunicationsignals thatarerandomlyDopplershifted. Theresultsareillustratedwithexamples ofspacecommunication. Hengelo(O),January2006 W. J. Witteman Contents 1 RandomFluctuations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 2 ThermalNoiseofResistance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. 3 ShotNoise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 3. 1 SpectralDistribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 3. 2 Photons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1. 4 FlickerNoise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1. 5 Generation–RecombinationNoise. . . . . . . . . . . . . . . . . . . . . . . . . . 10 1. 6 ThermalRadiationandItsFluctuations. . . . . . . . . . . . . . . . . . . . 13 1. 7 TemperatureFluctuationsofSmallBodies. . . . . . . . . . . . . . . . . . 18 1. 7. 1 AbsorptionandEmissionFluctuations. . . . . . . . . . . . . . . 20 2 Signal–NoiseRelations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2. 1 SignalLimitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2. 2 BackgroundLimitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2. 2. 1 IdealDetection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2. 3 JohnsonNoise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. 4 DarkCurrentNoise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. 5 NoiseandSensitivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2. 6 Ampli?erNoiseandMismatching. . . . . . . . . . . . . . . . . . . . . . . . . . 28 3 ThermalDetectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3. 1 ThermocoupleandThermopile. . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3. 2 Bolometer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3. 2. 1 MetallicBolometer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3. 2. 2 Thermistor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 3. 3 PyroelectricDetector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4 VacuumPhotodetectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4. 1 VacuumPhotodiode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4. 2 Photomultiplier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 X Contents 5 SemiconductorPhotodetectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 5. 1 Photoconductors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 5. 1. 1 AnalysisoftheDetectionProcess. . . . . . . . . . . . . . . . . . . . 64 5. 1. 2 FrequencyResponse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5. 2 Photodiodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5. 2. 1 P–NJunction. . . . . . . . . . . . . . . . . . . . . .

W. J. Witteman has been professor in laser physics at the University of Twente (The Netherlands) from 1969 until 1999. Next to numerous articles in the field of CO2-lasers, excimer lasers and free electron lasers he has published:

In 1987 "The CO2 Laser" (Springer Series in Optical Sciences, Vol.54)

In 1996 as co-author "Gas Lasers-Recent Developments and Future Prospects" (Kluwer Academic Publishers)

In 2004 as co-author "Handbook of Laser Technology & Applications" (Institute of Physics Publishing). He was the author of the chapter on "Excimer, F2, N2 and H2 Lasers".