Ultra-Stable High-Performance Single Nanolasers

Lead Research Organisation: University of Sheffield
Department Name: Electronic and Electrical Engineering


2015 was designated by the United Nations as the 'International Year of Light and Light-Based Technologies'. World-wide activities during the year highlighted the importance of photonics in industry, health care and education. Those activities - strongly supported by the UK - has led strong credence to the claim that photonics is the key technology of the 21st century. During the 20th century the UK delivered key advances in photonics technology including the development of low-loss optical fibres, pioneering work in semiconductor laser development and the invention of optical fibre amplifiers. That inventiveness is the foundation of optical fibre communications whose maturity has enabled year-on-year growth in data traffic including web-based products and services. The internet already consumes in excess of 5% of the world's electricity and is projected to consume 10% of that capacity very soon. As it is expected that growth in internet traffic will continue it is apparent that the demands placed on electricity sources could become unsustainable. Moreover, due to delays in decisions on the provision of new electricity generation capacity as well as vacillations in policy in respect of renewable energy sources, the UK is particularly vulnerable to excessive demands on electricity: the safety margin for generation has in the past few years declined from 15% in 2011/12 to a predicted 5% in 2015/16. The UK therefore has a particular need to advance technologies which will relieve demands on electricity usage. Photonics is such a technology and, specifically, the adoption of optical switching within compact photonic integrated circuits (PICs) will effect a dramatic reduction in electricity consumption: 40% of the internet electricity consumption is due to core switching operations.
One of the key requirements to achieving PICs is to miniaturize photonic components down to the nanometer scale, for instance, nanolasers. In this case, the bottleneck that must be overcome is due to the diffraction limit of light, namely, ~l/2n limiting the minimal dimensions of a laser cavity, where l and n are the free space wavelength and refractive index, respectively. It is also crucial to minimise energy consumption while using optical sources such as lasers for such compact PICs, and thus a laser with a very low threshold is essential. The use of surface plasmon polarition (SPP) modes excited at the metal dielectric interface offers a means for device size reduction down to the sub-wavelength range. The project will combine the expertise in simulation, design and testing of advanced nanolasers at Bangor, and the established epitaxial growth and advanced nanofabrication of GaN based optoelectronics at Sheffield to develop the first GaN based electrically-pumped single nanolasers. Building on analysis of stand-alone single nanolasers, it will be demonstrated that optimized nanolasers can be configured such that they remain immune to instabilities when subject to external optical influences. Such stability makes nanolasers ideal candidates for incorporation in complex photonic integrated circuits. This project will contribute to developing future photonic technologies which underpins the operation of the internet, Smart Phone and Tablet usage, satellite communications/GPS, Direct Broadcast TV, energy efficient solid state lighting, efficient solar power generation, consumer electronics, high capacity communications networks and data storage, advanced healthcare and ground-breaking biotechnology.


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