Generally there are three types of noise is present in the semiconductor radiation detector.These are Thermal Noise,Shot noise and Flicker Noise.The thermal noise is removed by operating the detector under low temperature.The Flicker noise can be removed by using High pass circuit.But How to eliminate the Shot noise in the Semiconductor radiation detector?The shot noise in the semiconductor radiation detector is due to the discrete flow of carrier in the device. I will be very much thankful for the help if any one suggest some method to eliminate the shot noise?
I don't believe you can eliminate shot noise, but if you can increase quantum efficiency it will improve the signal to noise ratio - other things being equal.
In the limit where you generate one carrier for each incident photon, you will be limited by photon arrival statistics - generally described by a similar Poisson distribution to shot noise.
If you generate multiple carriers from each incident photon, there is additional noise to that defined by the photon arrival rate.
If there is a bias current which is independent of incident radiation, this will also contribute shot noise. Cooling the detector should reduce this.
Dear Manoj, Suppose constant power of nearly monochromatic radiation incident on a photodetector and randomness of emission times of the photoelectron, which obeys the Poisson probabilty distribution. Since the emission events occurs at the average rate, the average number Nbar of of the photoevents occuring in time T is proportional to T. While rms fluctuation (DN)rms is calculated proportinal to the square root of Nbar, Then fractional fluctuation (DN)rms/Nbar is 1/Nbar^0.5, which becomes arbitrarily small by increaing the integration time T. Shigeo
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