1. A Moores law for integrated photonics, the KTH view
A Moore´s law for integration density in terms of equivalent number
of elements per square micron of integrated photonics devices:
Growing faster than the IC Moore´s law ?
A Moores law for integrated photonics, the KTH view
This “Moore’s law” in integration density for photonics, published in 2006 [1] and continuously updated depicts results from the Stockholm area over the years, from the first polarization independent 4x4 LiNbO3 switch over the first lossless InP amplifier gated tree structures switches to a silicon arrayed waveguide grating device. The uppermost device is a theoretical design of a switch based on coupled metal nanoparticle array waveguides and the insert to the right is an experimental directional coupler partly based on so called hybrid plasmonics. It should be noted that the two latter have much higher insertion loss than the previous samples.
Such exponential development in integration density is also evidenced in other publications, though with different metrics. Much of recent development to ever smaller structures, one condition for integratability and low power dissipation , an increasingly important metric, has been based on plasmonics, where the losses, however, give an unforgiving barrier to many practical applications. The limits and tradeoffs involved here were researched [2,3] as well as the principal possibility to compensate loss with gain in resonantly operated plasmonics devices (i.e. where the light confinement is highest) [4], with e.g. quantum-dot (QD) based amplification in composite particle arrays. It was shown that in highly integrated systems power dissipation and (in ICT systems) signal-to-noise ratio degradation are rather forbidding [5]. And indeed, development in shrinking dimensions for e.g. filters and modulators seems to have slowed down. Power dissipation or Joule heating in the context of nanophotonics is an important parameter, both from more fundamental aspects and for applications, where it could be a limiting factor, as it indeed is for electronics ICs.
References
[1] L Thylen et al, J. Zhejiang Univ SCIENCE (12) p
[2] P. Holmström, J. Yuan, M. Qiu, L. Thylén, and A. M. Bratkovsky, “Passive and active plasmonic nanoarray devices”, Proc. SPIE 8070, pp T-1-6 (2011).
[3] P. Holmström, J. Yuan, M. Qiu, L. Thylén, and A. M. Bratkovsky, “Theoretical study of nanophotonic directional couplers comprising near-field-coupled metal nanoparticles”, Opt. Express 19, pp (2011).
[4] P. Holmström, L. Thylen, and A. Bratkovsky, “Composite metal/quantum-dot nanoparticle-array waveguides with compensated loss”, Appl. Phys. Lett. 97, p , 2010.
[5] L. Thylen, P. Holmström, A. Bratkovsky, J. Li, S.-Y. Wang, “Limits on integration as determined by power dissipation and signal-to-noise ratio in loss-compensated photonic integrated circuits based on metal/quantum-dot materials“, IEEE J. Quantum Electron. 46, pp , 2010
L Thylen et al, J. Zhejiang Univ SCIENCE (12) p