Accurate Measurement of Noise Parameters in Ultra-Low Noise Opto-Feedback Spectrometer Systems

The accurate measurement of the basic noise parameters of ultra-low noise spectrometer systems has been developed in the frequency domain by spectrum analysis. This method overcomes some of the difficulties experienced in using cmventional techniques. An analytic and experimental comparison between ´time´ and frequency domain techniques is carried out and the use of the latter as a method to develop extremely low-noise detector and FET packages is demonstrated. The origin of the remaining noise in high quality systems is traced to surface and gate junction generation through traps in the FET.