Nav: Home

The world's first all-Si laser

January 17, 2018

Integrated Si photonics incorporates the essence of the two pillar industries of "microelectronics" and "optoelectronics", which is expected to bring new technological revolution in a variety of fields such as communication, sensing, lighting, dispalay, imaging, detection, etc. Si lasers are the key to achieve integrated Si photonics. However, the optical gains of Si are lower than those of III-V compound semiconductors by one order of magnitude or two, due to its indirect bandgap feature. Although the fabrication of matured III-V compound lasers on Si substrates has been proposed to circumvent this problem, the development of all-Si laser is still in high demand for integrated Si photonics, due to its better compatibility with modern Si techniques.

Recently, a joint research team led by Prof. X. Wu, Prof. M. Lu and associate Prof. S.-Y. Zhang from Fudan University developed the world's first all-Si laser using Si nanocrystals with high optical gains. First, they enhanced the Si emission intensity greatly by developing a film growth technique for high-density silicon nanocrystals (Physica E, 89, 57-60(2017)). Then, they developed a high-pressure low-temperature passivation approach, which contributed to a full saturation of dangling bonds, leading to increased optical gains that were comparable to those achieved by gallium arsenide (GaAs) and indium phosphide (InP). On this basis, they designed and fabricated distributed feedback (DFB) resonance cavities and successfully achieved optically pumped all-Si DFB lasers. The optically pumped all-Si laser also paves the way towards the realization of electrically pumped all-Si laser.

It was found that the optical gain of Si nanocrystals was constantly enhanced as the passivation proceeded and eventually reached the value comparable to those of GaAs and InP. Lasing characteristics - the threshold effect, the polarization dependence, the significant spectral narrowing and small spread of divergence angle of stimulated emission - were fulfilled, suggesting the realization of an optically pumped all-Si laser. The lasers also showed reliable repeatability. The lasing peaks of the four additional samples made under the similar fabrication conditions were within the spectral range of 760 nm to 770 nm. The variation in the lasing peak was due to the slight difference in effective refractive indices. The full-width-at-half-maximum (FWHM) of the emission peak was narrowed from ~120 nm to 7 nm when the laser was pumped above threshold. This program is supported by the National Natural Science Foundation of China (51472051, 61275178, 61378080, 61705042) and Shanghai Sailing Program (16YF1400700).
Dong-Chen Wang#, Chi Zhang#, Pan Zeng, Wen-Jie Zhou, Lei Ma, Hao-Tian Wang, Zhi-Quan Zhou, Fei Hu, Shu-Yu Zhang*, Ming Lu*, and Xiang Wu*. An all-silicon laser based on silicon nanocrystals with high optical gains. Science Bulletin,

Science China Press

Related Laser Articles:

The sharpest laser in the world
With a linewidth of only 10 mHz, the laser that the researchers from the Physikalisch-Technische Bundesanstalt (PTB) have now developed together with US researchers from JILA, a joint institute of the National Institute of Standards and Technology and the University of Colorado Boulder, has established a new world record.
Biggest X-ray laser in the world generates its first laser light
European XFEL, the biggest X-ray laser in the world, has generated its first X-ray laser light.
Where does laser energy go after being fired into plasma?
An outstanding conundrum on what happens to the laser energy after beams are fired into plasma has been solved in newly-published research at the University of Strathclyde.
Over-the-counter laser pointers a threat to eyesight
Some laser pointers that can be bought over the counter are unsafe -- to the point that they can cause blindness.
Introducing the disposable laser
Since lasers were invented more than 50 years ago, they have transformed a diverse swath of technology -- from CD players to surgical instruments.
A laser for your eyes
A team of the Lomonosov Moscow State University scientists and the Belarusian National Technical University has created a unique laser, which is a compact light source with wavelengths harmless to the human eye.
New laser to shine light on remote sensing
A revolutionary new type of laser developed by the University of Adelaide is promising major advances in remote sensing of greenhouse gases.
Laser beams with a 'twist'
Using geometric phase inside lasers for the first time, researchers find a way to change the orbital angular momentum of laser beams.
New laser achieves wavelength long sought by laser developers
Researchers at the University of Bath, United Kingdom have created a new kind of laser capable of pulsed and continuous mid-infrared emission between 3.1 and 3.2 microns, a spectral range that has long presented a major challenge for laser developers.
New laser achieves wavelength long sought by laser developers
Researchers at the University of Bath, United Kingdom have created a new kind of laser capable of pulsed and continuous mid-infrared (IR) emission between 3.1 and 3.2 microns, a spectral range that has long presented a major challenge for laser developers.

Related Laser Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".