Microwave photonic links based on transistor lasers: Voltage modulation versus current modulation

Abstract

A three-port microwave photonic S-parameter formalism is developed and applied to the small-signal analysis of the transistor laser. This is then used to investigate the relationship between slope efficiency and link gain for microwave photonic links based on transistor lasers, for the two distinct cases of collector-emitter voltage modulation and base current modulation.

Circuit-level simulation of transistor lasers and its application to modelling of microwave photonic links

“…In doing so, the reverse modulation response (which is voltagedriven [5]) begins to contribute to link gain, and this can be increased up to a value of almost 6 dB compared to a single transistor laser that is terminated at both ports with 50 Ω (Figure 7). 10 Figure 6.…”

“…In recent papers [4], [5], we have advocated the use of an alternative device for direct modulation, namely the transistorlaser. The transistor-laser is a unique device that represents the homogeneous integration of a heterojunction bipolar transistor (HBT) with a diode laser (LD), thus combining lasing with electrical characteristics that are dominated by the transistor action.…”