NTT Research and Development 2009 Review of Activities

Overview

NTT has been studying photonic crystals^*1 for a decade, and had realized an ultrahigh-Q (Q~2 x 10⁶) nanocavity by which one can confine light pulses within a submicron volume for over a nanosecond. In FY2008, NTT demonstrated all-optical bit memory operation with unprecedented low driving power, enabled by the enhancement of light-matter interactions in photonic crystal nanocavities. Moreover, NTT has realized large-scale arrays of ultrahigh-Q coupled nanocavities, for the first time, and demonstrated slow light propagation with the velocity of c/170 (c: light velocity in vacuum).

Features

• Small power consumption: Tiny all-optical bit memory with 100 times smaller driving power compared to other optical bit memories
• Nanocavity integration: Large-scale array (the largest cavity number is 200) of ultrahigh-Q (Q~10⁶) nanocavities
• Slow light in a chip: Compact slow light waveguide with the light speed of c/170, which enables optical buffering and enhancement of light-matter interactions

Application scenarios

• All-optical switches and memories with extremely-low consumption power
• Large-scale integration of all-optical circuit
• All-optical logic circuits or integrated photonic random access memories
• Application to future ultrawide-band information processing, such as optical routers

• *1 photonic crystal: artificial nanostructure with periodic modulation of its refractive index.
• *2 This study of optical bit memories was supported by NICT (National Institute of Information and Communication Technology).