Researchers have turned nanowires into tiny lasers that could one day be used in high-resolution microscopy.

The resolution of optical microscopes is normally constrained by the wavelength of light. To overcome this 'diffraction' limit, a team led by Seok Hyun Yun at Massachusetts General Hospital in Cambridge made nanowires of lead iodide perovskite that were 3–7 micrometres long and just 300–500 nanometres wide. When the team scanned the nanoparticles with a laser, they emitted light. The narrow width of the nanowires allowed their positions to be tracked with resolutions roughly five times better than the diffraction-limited resolution.

Such nanolasers could one day be placed inside cells and yield super-resolution images from deep within tissue samples, the authors say.

Phys. Rev. Lett. 117, 193902 (2016)