Noise in Semiconductors: Spectrum of a Two-Parameter Random Signal

With intended application to the theory of current noise in semiconductors, the spectrum is calculated of a random signal which may be in one of two states (YES-NO: random telegraph signal), where the mean lives σ and τ of the two states may be different. The form of the spectrum is the same as for the case with equal lives, the single parameter τ for that (classical) case now being replaced by 2(1/σ)+(1/τ)−1; i.e., the rates of transition are additive.