In recent years, silicon photonics has made great strides. However, a key component has been missing until now. That has now changed.
The newly developed semiconductor laser for continuous operation consists entirely of elements of the silicon group.
Forschungszentrum Jülich / Jhonny Tiscareno
An international research team at Jülich Research Center has developed the first electrically pumped semiconductor laser for continuous operation that consists entirely of elements from the fourth main group – specifically, the silicon group. The new laser is based on ultra-thin layers of silicon-germanium-tin and germanium-tin and can be integrated directly into silicon chips. According to the Jülich Research Center, this solves a key problem of on-chip photonics: the seamless connection of optical and electronic components on a single chip.
Commonly used III-V semiconductors from other main groups are difficult to combine with silicon, which is a very essential material for chips. According to the Jülich Research Center, this makes production complex and expensive. The new laser closes this gap and can therefore be considered the last missing piece of the puzzle in silicon photonics. Since it is compatible with conventional complementary metal oxide semiconductor (CMOS) technology, it can be seamlessly integrated into existing silicon processes.
Stable continuous operation at 90 K
The laser is based on a so-called multi-quantum-well structure, which has been specially adapted to the properties of the alloys (silicon-germanium-tin and germanium-tin). Supplemented by a novel ring geometry, it is designed to minimize energy consumption and heat generation, thus enabling stable continuous operation at 90 K.
In contrast to earlier optically pumped germanium-tin lasers, the new laser also works electrically. To do this, it requires a current of 5 mA and a voltage of 2 V – comparable to an LED, according to Jülich Research Center. However, further optimization is needed. In particular, the laser threshold needs to be lowered further and stable operation at room temperature needs to be made possible.
This is a partly automated translation of this german article.
