Toward Bridging the Terahertz Gap with Silicon-Based Lasers

A laser emitting at terahertz wavelengths (30 to 300m or 1 to 10 THz) would be highly useful in medical and security applications, but current terahertz lasers are complex and expensive. In his Perspective, Borak discusses recent advances toward building a more practical, silicon-based terahertz laser, which would be compatible with the ubiquitous silicon technology. Currently, so-called quantum cascade lasers look like most promising, but a working silicon quantum cascade laser is still some way off.