A superhigh-frequency optoelectromechanical system based on a slotted photonic crystal cavity

Abstract

Abstract:We develop an all-integrated optoelectromechanical system that operates in the superhigh frequency band. This system is based on an ultrahigh-Q slotted photonic crystal (PhC) nanocavity formed by two PhC membranes, one of which is patterned with electrode and capacitively driven. The strong simultaneous electromechanical and optomechanical interactions yield efficient electrical excitation and sensitive optical transduction of the bulk acoustic modes of the PhC membrane. These modes are identified up to a frequency of 4.20 GHz, with their mechanical Q factors ranging from 240 to 1,730. Directly linking signals in microwave and optical domains, such optoelectromechanical systems will find applications in microwave photonics in addition to those that utilize the electromechanical and optomechanical interactions separately. a) Electronic mail: hong.tang@yale.edu.1 Nanoelectromechanical systems and nanooptomechanical systems that work at high frequencies have recently attracted great interest because of their use in studying mesoscopic quantum mechanics 1 as well as many practical applications such as high-speed sensing and coherent signal processing. [2][3][4][5][6][7][8][9] By combining these two types of systems into a single device where the mechanical degree of freedom is simultaneously coupled to both electrical and optical degrees of freedom, one achieves electro-optic interaction with capabilities that take advantage of the amplification from mechanical resonances. To this end, it is important to design a system possessing both strong electromechanical and optomechanical coupling such that the mechanical modes can be electrically excited efficiently and optically read out sensitively.Thin-film bulk acoustic resonators (TFBAR) are one type of electromechanical systems that have been widely used in wireless applications, where the microwave-frequency bulk acoustic modes are usually excited by a piezoelectric element which converts electrical energy directly into mechanical energy. 10 This work pursues an implementation on an all-silicon platform because of its maturity in electronics and photonics integration. Without the piezoelectric effect in silicon, excitation of the bulk acoustic modes is implemented through the capacitive force between a pair of patterned metal wires, one of which locates on an edge of the free-moving mechanical resonator and the other is fixed. The electromechanical coupling is thus provided via the strong dependence of the capacitance on the nanosized gap between the metalwire electrodes. 8 For optomechanical coupling, we employ slotted photonic crystal (PhC) nanocavities because of their simultaneous high optical quality (Q) factor and large optomechanical coupling. [11][12][13][14][15][16] The cavity is formed by a mode-gap confinement mechanism based on a variation from the corresponding slotted PhC waveguide. Among all the design schemes two are mostly implemented: one is tapering the lattice constant in the longitudinal 2 direction 11-13 and the other is shifting the ...

Microwave-assisted coherent and nonlinear control in cavity piezo-optomechanical systems

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Optomechanical detection of light with orbital angular momentum

“…The effective mass of this mode is m ef f = 27 pg, and is small compared to the slot-mode cavity in Ref. [41] due to its one-dimensional nature. For calculation of V , g OM , and m ef f , we have used the definitions in Ref.…”

“…This "air-band" cavity mode, which is analogous to slot-modes of two-dimensional photonic crystal from in Ref. [41], has high sensitivity to motion of the nanobeam that changes the slot gap width, and as a result, changes the optical response of the cavity through a dispersive optomechanical coupling. As shown in The device presented here is designed from a 370 nm thick silicon nitride (SiN) layer.…”

High-Q optomechanical circuits made from polished nanocrystalline diamond thin films

“…Using optical methods for read out of mechanical vibrations provides unconstrained bandwidth and higher sensitivity compared to an electrical measurement, having enabled the observation of radiation pressure shot noise [14] and squeezing of light below the vacuum noise level [15]. In addition to purely optically transduced systems, optoelectromechanical systems using piezoelectric [16] and electrostatic [17][18][19] actuation combined with optical read-out are currently explored because of the benefit of stronger motion build-up.…”