Optomechanical Detection of Light with Orbital Angular Momentum

TL;DR

This paper introduces an optomechanical device capable of detecting the orbital angular momentum of light by measuring mechanical twists induced by light's angular momentum, enabling new quantum and classical light measurements.

Contribution

The work presents a novel integrated optomechanical system that transduces orbital angular momentum of light into mechanical signals, extending detection capabilities to higher order states.

Findings

Detects $l=1$ orbital angular momentum with 3,900 photons.

Uses a nanobeam slot-mode photonic crystal cavity for transduction.

Potential to extend detection to higher orbital angular momentum states.

Abstract

We present an optomechanical device designed to allow optical transduction of orbital angular momentum of light. An optically induced twist imparted on the device by light is detected using an integrated cavity optomechanical system based on a nanobeam slot-mode photonic crystal cavity. This device could allow measurement of the orbital angular momentum of light when photons are absorbed by the mechanical element, or detection of the presence of photons when they are scattered into new orbital angular momentum states by a sub-wavelength grating patterned on the device. Such a system allows detection of a $l = 1$ orbital angular momentum field with an average power of $3.9\times10^3$ photons modulated at the mechanical resonance frequency of the device and can be extended to higher order orbital angular momentum states.