NTT Research and Development 2011 Review of Activities

Overview

Photonic crystal technologies enable us to make ultra-compact cavities with volumes less than 1 µm³. A laser with an ultra-low threshold can be made by decreasing the cavity volume. Moreover, a photonic network chip, which is a hybrid integration with silicon CMOS^*, must have appropriate output power for detecting the light at the photodetector and a high-speed direct modulation capability with very low power consumption. We have developed ultracompact buried heterostructure photonic crystal laser for such a purpose by employing the technologies of InP-based photonic integrated circuits.

Features

• World's smallest buried heterostructure (5.0 x 0.3 x 0.15 µm³) laser
• Ultralow threshold power (6.8 µW) and high output power (100 µW) achieved by optical pumping
• Extremely low energy consumption of direct modulated laser: 8.76 fJ/bit for 20-Gbit/s direct modulation with clear eye-opening
• Next step in development: PhC laser using electrical pumping.

Application scenarios

• High-density photonic integrated circuit
• Photonic network on chip: high-bandwidth density and reconfigurable photonic network on silicon CMOS
• CPU: continuous CMOS processor advances supported by energy-efficient optical system
• Green ICT: power efficient ICT equipment in data centers
• Other applications: ex. Ultra-small sensors requiring nano-scale light sources

• * CMOS: Complementary Metal Oxide Semiconductor