Coherent Magneto-optomechanical Signal Transduction and Long-Distance Phase-Shift Keying

Abstract

A transducer capable of converting quantum information stored as microwaves into telecom-wavelength signals is a critical piece of future quantum technology as it promises to enable the networking of quantum processors. Cavity optomechanical devices that are simultaneously coupled to microwave fields and optical resonances are being pursued in this regard. Yet even in the classical regime, developing optical modulators based on cavity optomechanics could provide lower power or higher bandwidth alternatives to current technology. Here we demonstrate a magnetically-mediated wavelength conversion technique, based on mixing high frequency tones with an optomechanical torsional resonator. This process can act either as an optical phase or amplitude modulator depending on the experimental configuration, and the carrier modulation is always coherent with the input tone. Such coherence allows classical information transduction and transmission via the technique of phase-shift keying. We demonstrate that we can encode up to eight bins of information, corresponding to three bits, simultaneously and demonstrate the transmission of an 52,500 pixel image over 6 km of optical fiber with just 0.67% error. Furthermore, we show that magneto-optomechanical transduction can be described in a fully quantum manner, implying that this is a viable approach to signal transduction at the single quantum level.

Observation of low-temperature magnetomechanic effects in crystalline resonant phonon cavities

“…It fits the new framework of magneto-mechanical systems that have re-cently emerged bringing together advantages of both spin and mechanical degrees of freedom. For example, such systems have been recently used for applications such as magnetometry [46] and optomechanical transduction [47].…”

Cavity magnonics

“…Indeed, magnons and photons may couple via an intermediate mechanical mode [295], exploiting the high sensitivity and large Q-factors of optomechanical systems. This kind of coupling has already been exploited in measurements of single spins in nitrogen vacancy centers of diamond [296], and as a possible route to highly efficient MW-to-optical transduction [297].…”

Coherent Conversion Between Microwave and Optical Photons—An Overview of Physical Implementations

“…Higher‐order magnetostatic modes, which are concentrated on the surface of the ferromagnet, may offer a route for improvement, although efficient coupling into such modes is difficult, requiring a highly non‐uniform driving field. Alternatives may include using magnetic modes in rare earth crystals, hybrid magneto‐optomechanical devices, and travelling spin waves in thin films …”