Bridging X-Ray and Visible Light using Optomechanics

This photo was taken in 2012 when Prof. Aspelmeyer visited MPIK. I and Adriana had a quite long discussion with him about how to implement the idea of cavity optomechanics in hard x-ray domain. Our first work following that exciting discussion is recently published in Sci. Rep. 7, 321 (2017). As one can see from an electromagnetism spectrum, to bridge optical photons (~1eV) and hard x-ray photons (~10keV) with a single device, we basically need a magic box having response to both extreme sides. To make this happen we propose a system made of a typical optomechanical cavity whose movable mirror can, on one hand, driven by an external optical laser, and on the other hand embedded with a, e.g., 57Fe nuclear layer on the tip. Any x-ray, e.g., of 14.4 keV for 57Fe, can then excite this nuclear layer whose mechanical vibration is manipulated by the optical laser, e.g., power. Think about the Doppler shift of nuclear absorption lines due to its controlled phonon state, we demonstrate that the x-ray absorption spectra of the device can be modified by an optical laser. More specifically, the so called optomechanically induced transparency of x-ray is also predicted. You see! It's already an one way interface connecting two wavelengths. We are looking forward a future upgrade toward a true two-way interface used in, e.g., a photonic network.