Since the proposal of the concept of photonic integratedcircuits (PICs), tremendous progress has been made. In2005, Infinera Corp. rolled out the first commercial PICs, inwhich hundreds of optical functions were integrated onto asmall form factor chip for wavelength division multiplexing(WDM) systems[1], then a monolithically integrated 10 ×10 Gb/s WDM chip has been demonstrated, the channelnumber is ten[2]. Like ICs, large-scale PICs (LS-PICs) will besure to be pursued. However, there are still some generalchallenges associated with LS-PICs. The challenges for III–V(mainly InP) PICs is the semiconductor process, which is notmature for LS-PICs. Up to now, the channel number in commercialIII–V WDM PICs by Infinera is still about ten or less.For silicon photonics, the challenge is the silicon based lightsource. The low cost and mature solution for silicon lasers isstill unavailable and only 4 × 25 Gb/s PICs are deployed byIntel Corp. after 18-year R&D investment. Thus it is still unavailablefor practical LS-PICs in the present times.
展开▼
