The three systems for low frequency noise measurements of an optoelectronic coupled device (an infrared emitting diode and a phototransistor) were described. In the system I a low frequency noise of an infrared diode was measured, in the system II a low frequency noise of a phototransistor was measured, in the system III a low frequency noise of an optoelectronic coupled device was measured. The investigations were carried out for optoelectronic coupled devices of CNY type. The results of noise measurements in three systems are compared and a main source of noise in optoelectronic coupled devices was evaluated.
The low frequency noise generated by optoelectronic coupled devices (OCDs) was measured in the system designed and constructed by authors. The investigations were carried out for optoelectronic devices of CNY 17 type. Number of N = 106 noise samples was recorded for statistical analysis for each investigated OCD. The amplitude distributions and cumulative distribution functions were calculated for each samples data records. Statistical properties of low frequency noise of OCDs were established by estimating following parameters: mean value, variance, skewness and kurtosis. The investigated time series have not Gaussion distributions. Stationarity of the four estimated parameters was tested. It was found that the probability density function of noise could be used for the recognition of the Random Telegraph Signal (RTS) noise together with spectrum analysis.