Low-noise current-mode optical preamplifier

Positive-intrinsic-negative (PIN) photodiode bipolar junction transistor (BJT) and MESFET transimpedance optical preamplifiers with very low noise properties are described. Two current-mode designs are considered, an improved common-base current-feedback configuration and a novel complete MESFET common-gate current-feedback configuration. Measured performances of these new topologies at a 100-MHz bandwidth are compared with those of classical designs, demonstrating that, in general, better noise performance with much higher transimpedance gain can be obtained with these new current-feedback structures