Noise signal half width determination esp. for photon correlation - involves using time integral of autocorrelation function esp. with microprocessor control

摘要

The half width of noise signals with lorentz distribution of the power density spectrum is determined automatically using a microprocessor which has a fixed programme to form the integral of the autocorrelation function of the noise signal and determines the half width from this integral. Pref. the noise signal is fed through a pre-amplifier and an input filter to an analogue/digital converter which is followed in circuit by a data store and a multiplier/adder. A central controller extracts the data from the store and feeds them under programme control to the multiplier/adder. An integration operation follows the adding stage to form the time integral of the autocorrelation function, and the half width is then calculated from the time integral by an evaluation stage.