Journal Article

An all-silicon Raman laser

Rong, Haisheng, Nicolaescu, Remus, Liu, Ansheng, Hak, Dani, Paniccia, Mario, Cohen, Oded, Jones, Richard, Fang, Alexander

2005

Overview

Bright future for ‘optical’ silicon With the growing use of optoelectronics in information technology, manipulating light is almost as important as manipulating electrons. Unfortunately silicon, workhorse of modern microelectronics, is next to useless in optical applications. There has been a massive effort to overcome silicon's inadequacies, and ways of coaxing silicon to handle light are under development but a key component — the laser — has been problematic. Last year a silicon laser was produced, but it involved metres of optical fibre. Now workers in Intel's research labs have come up with an all-silicon laser on a single chip. The device is compact and readily integrated with other silicon components. The possibility of light generation and/or amplification in silicon has attracted a great deal of attention 1 for silicon-based optoelectronic applications owing to the potential for forming inexpensive, monolithic integrated optical components. Because of its indirect bandgap, bulk silicon shows very inefficient band-to-band radiative electron–hole recombination. Light emission in silicon has thus focused on the use of silicon engineered materials such as nanocrystals 2 , 3 , 4 , 5 , Si/SiO 2 superlattices 6 , erbium-doped silicon-rich oxides 7 , 8 , 9 , 10 , surface-textured bulk silicon 11 and Si/SiGe quantum cascade structures 12 . Stimulated Raman scattering (SRS) has recently been demonstrated as a mechanism to generate optical gain in planar silicon waveguide structures 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 . In fact, net optical gain in the range 2–11 dB due to SRS has been reported in centimetre-sized silicon waveguides using pulsed pumping 18 , 19 , 20 , 21 . Recently, a lasing experiment involving silicon as the gain medium by way of SRS was reported, where the ring laser cavity was formed by an 8-m-long optical fibre 22 . Here we report the experimental demonstration of Raman lasing in a compact, all-silicon, waveguide cavity on a single silicon chip. This demonstration represents an important step towards producing practical continuous-wave optical amplifiers and lasers that could be integrated with other optoelectronic components onto CMOS-compatible silicon chips.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Applied sciences / Circuit properties / Electric, optical and optoelectronic circuits / Electronics / Erbium / Exact sciences and technology / Fundamental areas of phenomenology (including applications) / Humanities and Social Sciences / Integrated optics. Optical fibers and wave guides / Lasers / letter / multidisciplinary / Optical and optoelectronic circuits / Optics / Physics / Raman lasers / Science / Science (multidisciplinary) / Silicon / Silicon wafers