NTT develops a current-injection laser with ultralow power consumption

Explosive diffusion of broadband services such as FTTH and smartphones are expected to lead to network traffic 200 times increase and the total power consumed by ICT-related equipments 5 times during the coming 20 years. NTT laboratories have focused on finding a radical solution to reduce the power consumption of microprocessors (MPU), since MPUs consume most of the power in ICT-related equipments.

NTT Laboratories have developed a lamda (wavelength)-scale embedded active region photonic- crystal (LEAP) laser, in which a wavelength-scale InGaAsP-based active region is embedded in an InP based photonic-crystal (PhC) waveguide. This LEAP laser achieved the world's first continuous-wave operation of a current-injection-photonic crystal laser at room temperature (25-30°C).
An ultralow effective operating current of 10 ìA was realized and the output power of 1.8 ìW was obtained at the current level of 2.0 mA. NTT claims that this result was obtained by a unique structural feature of the present LEAP laser, where the current injection is performed by lateral pin junctions into the active region.

NTT seems to consider that the operating characteristics of the fabricated LEAP laser is an answer to the request of future optical interconnects in CMOS MPUs presented in International Technology Roadmap 2007 ITRS (http://www.itrs.net/Links/2007ITRS/Home2007.htm).