New Kids on the Block: Photonic Integrated Circuits and Photonic Packet Switching (PPS)   

This is perfect timing and is music to the ears of operators and carriers. They are well aware of the fact that ever-increasing bandwidth demand is creating a new performance bottleneck: namely the switching electronics at the cores’ network nodes. The magic keyword is PIC (Photonic Integrated Circuit). They are the optical counterpart of electronic integrated circuits and stem from extensive R&D in the field of nano-photonics. PICs are promising candidates to kill two birds with one stone; they provide a significant increase in node bandwidth capacity and at the same time a substantial reduction in operational expenses.   

The goal of photonic integration is to combine multiple optical functions together on the very same material/substrate (in almost all cases a semiconductor wafer). The driving motivation is to generate savings in manufacturing cost, material cost, space, power consumption and increase reliability. The integration includes passive functions such as waveguides, filters, switches, multiplexers, couplers, variable optical attenuators and active functions such as lasing, modulation, PIN detection, and amplification.   

There is a reason for the strong activity around PICs. IBM predicts on-chip optical connections could be 100 times faster ­while using only one-tenth of the power.    

Of course, compared to the mature and well established electronic IC Technology, PIC is still in an early stage. State of the art PICs today provide about 50-230 components/functions per chip whereas electronic ICs boast more than one billion combined functions per chip  However, with respect to speed and power consumption, PICs impose a serious threat to electronics for specific applications and might even be disruptive. The PIC technology is the fundamental principle upon which the PPS technology is based. Therefore the success of PPS is directly linked to the success of the PIC.   

The definition of a PPS-based network is an optical network ­capable of providing packet-switched services purely at the optical level. This should not be confused with wavelength routing or optical switching. Although for both switching/routing is done without OEO, PPS performs packet-switched services while the latter is based on a type of circuit-switching.