World’s first plasma lens keeps 80% of attosecond light power

Scientists from the Max Born Institute (MBI) in Berlin and DESY in Hamburg have developed the world’s first plasma lens capable of focusing attosecond light pulses—flashes lasting billionths of a billionth of a second. This breakthrough addresses a major challenge in ultrafast physics: attosecond pulses lie in the extreme-ultraviolet (XUV) or X-ray range, where traditional mirrors and lenses either poorly reflect, degrade quickly, or absorb and distort the pulses. By using plasma, a charged gas, the team created a lens that can focus attosecond pulses efficiently without significant loss of power or temporal stretching. The plasma lens is formed by sending strong electrical pulses through hydrogen gas inside a narrow capillary tube, ionizing the gas and shaping the plasma into a concave lens. Unlike conventional lenses that would spread light, this plasma lens focuses the attosecond pulses across a wide range of XUV wavelengths, with adjustable focal length controlled by plasma density. Impressively,