We just published a new paper on Scientific Reports: Thermal noise and optomechanical features in the emission of a membrane-coupled compound cavity laser diode, by L. Baldacci, A. Pitanti et al.
In this paper, laser self-mixing technique was pushed to new limits allowing for the measurement of the thermal motion of a mirror suspended on a trampoline membrane.
Laser light is shined onto the membrane and then reflected back into the laser cavity: since the membrane is shaking due to its own temperature (remember the Fluctuation-Dissipation theorem), the external cavity length is modulated; conversely this also modulates the laser gain and consequently the emitted power.
It’s just as the membrane workout is pumping up the light!
Click here to read the full article.