Broadband Reconfiguration of OptoMechanical Filters

TL;DR

This paper demonstrates a broad-band reconfigurable opto-mechanical filter using optical gradient forces to tune photonic crystal nanobeam cavities over 18 linewidths, with independent control of mechanical and optical resonances.

Contribution

It introduces an all-optical reconfiguration method for photonic filters using optical gradient forces, enabling wide tuning range and independent resonance control.

Findings

Over 18 linewidths of tuning range achieved.

20% of tuning due to optomechanical reconfiguration.

Independent control of mechanical and optical resonances demonstrated.

Abstract

We demonstrate broad-band reconfiguration of coupled photonic crystal nanobeam cavities by using optical gradient force induced mechanical actuation. Propagating waveguide modes that exist over wide wavelength range are used to actuate the structures and in that way control the resonance of localized cavity mode. Using this all-optical approach, more than 18 linewidths of tuning range is demonstrated. Using on-chip temperature self-referencing method that we developed, we determined that 20 % of the total tuning was due to optomechanical reconfiguration and the rest due to thermo-optic effects. Independent control of mechanical and optical resonances of our structures, by means of optical stiffening, is also demonstrated.