Abstract

Feedback proportional to the derivative of a measured variable in a system ('derivative feedback') is attractive for many applications since it affects the stability of the system without changing the steady state^[1,2]. Recent work^[2] on laser systems with a combination of positive and negative optoelectronic derivative feedback demonstrated regenerative amplification of noise in bands of modulaton frequencies near the low-frequency relaxation oscillation frequencies. In extreme cases the regenerative amplification excited sustained dynamical pulsations.

© 1998 IEEE