Low Temperature Ringdown Measurements of GaAs Photonic Crystal Nanobeams*

Recent work done by Balram et al. demonstrated GaAs photonic crystal nanobeams as a potential tool for microwave to optical photon conversion using a room temperature mechanical mode [1]. High efficiency transfer relies on large cooperativity (C>1) between the mechanical and optical modes, which can be achieved by reducing the temperature of the devices to decrease the mechanical damping rate. In my poster, we present preliminary low temperature measurements of the of the 2.4 GHz breathing mode of the GaAs nanobeams, where we use an optical two-pulse technique adapted from Meenehan et al. [2]. Using this technique, we are able to determine the low temperature quality factor of the GaAs nanobeams by observing the ringdown time of the thermal motion in the breathing mode, which would otherwise be obscured by the heating of a continuous optical measurement.


[1] Balram, K. C., Davanco, M. I., Song, J. D., & Srinivasan, K. (2016). Nature Photonics, 10(5), 346-352.
[2] Meenehan, S. M., Cohen, J. D., MacCabe, G. S., Marsili, F., Shaw, M. D., & Painter, O. Physical Review X, 5, 041002