The main difference between a PIC chip and an integrated circuit is that the integrated circuit consists of many transistors, diodes, resistors and capacitors, whereas a PIC chip contains optical components such as laser diodes, modulators, photodetectors, optical multiplexers, optical amplifiers and transimpedance amplifiers. Large-scale PICs contain dozens of the above components. In addition, Photonic Integrated Circuits can be hybrid and monolithic.
In hybrid PICs, various individual optical components are integrated into a single package and may be combined with electronic integrated circuits (IC). The assembly of hybrid PICs is extremely complex, as many components must be internally adjusted and interconnected to ultra-low micron tolerances. The hybrid circuits support access and management of services and applications delivered over the transport network. This includes monitoring data transmission performance, tracking quality-of- service agreements, switching different data streams into larger transmission facilities, enabling rapid network reconfiguration during operation and flexible addition and deletion of services, and providing robust fault detection and protection to prevent service outages.
In contrast, photonic circuits are about wavelength division multiplexing(WDM), optical couplers, optical multiplexers, optical modulators and optical amplifiers, scalability and advanced optical signal transmissionbetween nodes in the wavelength range between 800 nm and 1,600 nm.