Transistor laser-integrated photonics for optical logic: Unlocking unique electro-optical integration potential to open up new possibilities for logic processors

The transistor laser benefits from a fast electron-hole recombination lifetime in the base due to its heterojunction bipolar transistor (HB T)-like operation and can be modulated using the base current or the collector voltage through intracavity photon-assisted tunneling (ICPAT). Both modulation processes are inherently high speed and put the transistor laser at a direct advantage over the diode laser as an optical transmitter. However, the true potential of the technology is the natural coexistence of transistor and laser on the same epitaxial structure, enabling monolithic integration of electrical and optical functions on the same wafer without the need for hybrid methods, such as wafer bonding and regrowth. As such, the transistor laser device structure is the ideal platform for integrated photonics. A transistor laser circuit combined with an optical receiver can process signals without the need for discrete electronic processing and electro-optical conversion components. This unique trait opens the possibility for a transistor laser-based all-optical logic processor, as demonstrated using a transistor laser all-optical NOR gate.