Shortest laser wavelength

Who: University of Electro-Communications
What: 0.15 nanometre(s)
Where: Not Applicable
When: 2009 - 2015

Lasers operate across a range of wavelengths, typically between 200 and 700 nanometres. In April 2009, the Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center in Stanford, California, USA, achieved a 0.15-nanometre wavelength – the first free-electron laser to emit hard X-rays. On 26 August 2015, scientists from The University of Electro-Communications in Tokyo, Japan, published in the journal Nature that they had created an atomic X-ray laser also with a wavelength of just 0.15 nanometres.

Visible light that the human eye can see ranges from around 390 to 750 nanometres.

The LCLS is extremely powerful and can emit pulses of X-ray laser radiation that last just 100 femtoseconds, containing some 10 trillion X-ray photons.

The team from The University of Electro-Communications bombarded a thin copper sheet with X-ray pulses of different energies, causing the copper atoms to emit photons that are turned into a laser by a second X-ray pulse. They are currently working on making lasers with such short wavelengths more stable with potential applications in medicine and particle physics in mind.