Photothermal Self-Oscillation and Laser Cooling of Graphene Optomechanical Systems

Abstract

By virtue of their low mass and stiffness, atomically thin mechanical resonators are attractive candidates for use in optomechanics. Here, we demonstrate photothermal back-action in a graphene mechanical resonator comprising one end of a Fabry-Perot cavity. As a demonstration of the utility of this effect, we show that a continuous wave laser can be used to cool a graphene vibrational mode or to power a graphene-based tunable frequency oscillator. Owing to graphene's high thermal conductivity and optical absorption, photothermal optomechanics is efficient in graphene and could ultimately enable laser cooling to the quantum ground state or applications such as photonic signal processing.

All-Optical Blister Test of Suspended Graphene Using Micro-Raman Spectroscopy

“…However, being atomically thin, a single layer of graphene is quasitransparent over the infrared and visible ranges 10,11 . These features allow the optical readout of mechanical resonances 6,7,12,13 and open perspectives for optomechanical studies 14 .…”

Optical Third-Harmonic Generation in Graphene

“…Despite its monolayer-to-few-layer thickness, graphene offers an array of properties that are of interest for optical physics and devices. These properties include relatively flat optical absorption from around 0.5 to 1.5 eV, with a strong dopingdependent absorption edge and pronounced excitonic effects [5][6][7][8][9]; coupling of optical and mechanical properties in graphene membranes [10]; and plasmonic properties [11,12]. Such studies have underscored the importance of the linear optical properties of graphene [5][6][7][8][9][13][14][15].…”

Microphotonic Forces from Superfluid Flow

“…Recent progress has seen radiation pressure used for coherent state swapping [13], ponderomotive squeezing [14], and ground state cooling [15], while static gradient forces have enabled all-optical routing [16] and nonvolatile mechanical memories [17]. Likewise, photothermal forces, where the mechanical element moves in response to mechanical stress from localized optical absorption and heating, have been used to demonstrate cavity cooling of a semiconductor membrane [18,19], single molecule force spectroscopy [20], and rich chaotic dynamics in suspended mirrors [21].Here, we demonstrate an alternative photoconvective approach to optical forcing that allows an order-ofmagnitude stronger mechanical actuation than radiation pressure. In our implementation, this technique utilizes the convection in superfluids, whereby frictionless fluid flow is generated in response to a local heat source.…”