X-rays are typically produced with ultrashort laser pulses, but until now the resulting frequencies were locked to specific values, like individual notes on a scale. Researchers at TU Wien and the University of California San Diego have now demonstrated a method that allows the frequency to be tuned continuously, offering far greater flexibility.
The team describes the effect as analogous to a guitarist bending a string, letting the pitch glide smoothly from one harmonic to another. Instead of being stuck with discrete frequency steps, the X-ray output can be adjusted to any value in a continuous range.
This breakthrough could simplify experiments that rely on precise X-ray wavelengths, though the source does not detail specific applications. The work is reported by Phys.org, and no conflicting information is presented.