Inducing forced and auto-oscillations in one-dimensional photonic crystals with light

J Eduardo Lugo,Noemi Sanchez,Jocelyn Faubert,Rafael Doti

doi:10.1117/1.jnp.8.083071

Abstract

We induced forced and auto-oscillations in one-dimensional photonic crystals (1-D- PCs) with localized defects when light impinges transversally to the defect layer. The photonic structure used consists of a microcavity-like structure formed of two 1-D-PCs made of free- standing porous silicon, separated by a variable air gap (the defect) and the working wavelength is 633 nm. The force generation was made evident by driving a laser light by means of a chopper; the light hit the photonic structure and induced a vibration and the vibration was characterized by using a very sensitive vibrometer. For example, we measured peak displacements and velocities ranging from 2 to 167 μm and 0.4 to 2.1 mm∕s with a power light level from 2.6 to 13 mW. In comparison, recent evidence showed that giant resonant light forces could induce average veloc- ity values of 0.45 mm∕s in microspheres embedded in water with a 43-mW light power. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. (DOI: 10.1117/1.JNP.8.083071)

Highlights

The concept of radiation pressure has been used in the past for manipulating micro-objects.1 For example, optical tweezers are used to levitate viruses, bacteria, cells, and subcellular organisms.2 Tweezing in free space with laser beams was established in the 1980s, but integrating the optical tweezers on a chip was a challenging task until recently
If we plot the Downloaded From: https://www.spiedigitallibrary.org/journals/Journal-of-Nanophotonics on 08 Nov 2021 Terms of Use: https://www.spiedigitallibrary.org/terms-of-use electromagnetic force at resonance against light power (Fig. 6), the relationship is linear with a slope of 19.7 nN∕mW
We found the highest electromagnetic force values whose order of magnitude is comparable with theoretical values predicted close to resonance

Summary

Introduction

The concept of radiation pressure has been used in the past for manipulating micro-objects. For example, optical tweezers are used to levitate viruses, bacteria, cells, and subcellular organisms. Tweezing in free space with laser beams was established in the 1980s, but integrating the optical tweezers on a chip was a challenging task until recently. Reference 3 shows an alternative approach, where the shape of the optical trap can be tuned by the wavelength in coupled nanobeam cavities. Using these shapeable tweezers, the micromanipulation of polystyrene microspheres trapped on a silicon chip is achieved. The radiation pressure is too small for these kinds of applications.. A second approach is with a Bragg waveguide based on a Fabry–Perot cavity in which the peak of the force only appears at the structures’ resonant frequencies and the force is normal to the waveguide wall.. A third approach can use a onedimensional photonic crystal (1-D-PC) with structural defects, where a localized mode results in strong electromagnetic fields around the position of the defect. The strong fields enhance the tangential and normal forces on a lossy dielectric layer.

Methods

Results

Conclusion