Increasing the stability margins using multi-pattern metasails and multi-modal laser beams

Abstract

Laser-driven metasails can enable reaching velocities far beyond the chemically propelled spacecrafts, which accounts for precise engineering of the acceleration and the stability degree of the lightsail across the Doppler-broadened band. All-dielectric metasurfaces have shown great promise toward the realization of low-weight photonic platforms suitable for integrating multiple functionalities. The most paramount factor in the stability analysis of lightsail is the coupling between displacement and rotation, which mainly determines the durability of the nanocraft against displacement and rotation offsets. In this work, the marginal stability conditions of laser-propelled lightsails have been extended by replacing the reflective elements near the edges portions of the sail with broad-band transmissive elements and applying a multi-objective genetic algorithm (GA) optimization to the proposed configuration. The presented design not only remarkably suppresses the amplitude of the oscillatory motion but also can decrease the center of the mass requirement of the lightsail while maintaining an acceptable acceleration time. Next, a configuration where the payload is at the non-illuminating side of the dual-portion sail is proposed to protect the payload from the intense laser beam. In this case, a spherical phase profile is imprinted across the reflective elements while it is being propelled by a multi-modal beam.

Controlling solar radiation forces with graphene in plasmonic metasurface

“…The chemical potential level of a graphene sheet can be easily manipulated via gating or doping, which in turn changes its optical properties [23]. Thus, graphene is an enticing candidate for integration with metasurfaces due to its ability to turn many optical configurations into an active device with applications in light-sailing, beam deflecting, optomechanics, and thermal camouflage [24][25][26][27][28][29][30] as well as metasail design [31,32]. Furthermore, the excitation of plasmonic modes of the metallic nanoresonators, utilized in the metasurfaces unit cells, creates vigorous near-field intensity, improving the light-graphene interaction.…”

Optical Manipulation of Nanoparticles: A Selective Excitation Approach Using Highly Focused Orbital Angular Momentum Beams

“…Momentum exchange of light with the matter can exert radiation pressure and optical gradient forces on the object, which has been exploited for different applications, including optical manipulation [40][41][42][43] and optical levitation of macroscopic objects and accelerating relativistic lightsails. [44][45][46][47][48][49][50][51] Besides, HFOBs with different polarization and OAM states have been used for diverse nanoparticle manipulation applications, such as optical trapping [52] and tweezers. [53] The complex beam profile of HFOBs can provide optical gradient forces that compete with the radiation pressure, resulting in a compelling optical force response.…”

High-quality-factor space–time metasurface for free-space power isolation at near-infrared regime

“…In particular, the widely used methods for the realization of high Q-factor modes are built upon the Fabry-Perot cavity resonators, 41 whispering-gallery mode platforms, 42,43 and guided mode resonators. 44,45 More recently, the concept of bound states in the continuum (BICs) has triggered extensive attention, since it is capable of yielding a Q-factor up to 10 8 in extended systems, such as photonic crystal slabs or plasmonic and dielectric metasurfaces. 40,46 Although for any platform comprising regular materials, where the permittivity and permeability are neither zero nor infinite, BICs can only be excited if the dimension is infinite, by modifying the parameters of a finite system to follow its infinite counterpart, quasi-BICs (QBICs) can be supported.…”

“…Thus far, several structures have been proposed for increasing the light–matter interactions at the nanoscale level. In particular, the widely used methods for the realization of high Q-factor modes are built upon the Fabry–Perot cavity resonators, 41 whispering-gallery mode platforms, 42 , 43 and guided mode resonators 44 , 45 . More recently, the concept of bound states in the continuum (BICs) has triggered extensive attention, since it is capable of yielding a Q-factor up to 108 in extended systems, such as photonic crystal slabs or plasmonic and dielectric metasurfaces 40 , 46 …”