In superconducting quantum computers, scaling the control wiring infrastructure poses significant challenges. Optical fibers present a promising alternative to traditional microwave cables, offering advantages such as lower passive heat load, reduced channel footprint, decreased crosstalk, and the potential for optical frequency multiplexing.
This work explores the conversion of microwave signals to optical signals via amplitude modulation and their subsequent reconversion to microwave signals at millikelvin (mK) temperatures. We analyze qubit performance with optically mediated control and compare it to conventional microwave control. We show that the main limitation of driving a qubit via the optically mediated control is qubit heating. Additionally, we investigate the optimal operation region for the setup with different laser diode bias currents, photodiode bias voltages and RF input power to achieve a tradeoff between power dissipation and signal noise.
Theoretical methods for reducing power dissipation are also explored, particularly through the integration of the photodiode into the qubit package.
By addressing these factors, we aim to advance the use of optically mediated control in superconducting quantum computing as an approach to tackle the passive headload and footprint challenge of RF wiring from RT to the mK stage.