کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1532792 | 1512267 | 2012 | 13 صفحه PDF | دانلود رایگان |
This paper shows, using both a ray optics approach and in the framework of the generalized Lorenz–Mie theory (GLMT), what happens to the optical forces exerted on a lossless spherical particle with an arbitrary (positive or negative) relative refractive index, allowing the external medium also to be metamaterial. It is shown that the anti-parallelism between the linear momentum p of each photon and the Poynting vector S associated with the propagating wave, observed in negative refractive index media, leads to shifts in the direction of the optical force of a single ray and, consequently, to the total optical force exerted by an arbitrary-shaped laser beam. This extends the possible realizable traps and reveals how arbitrary-shaped laser beams can be used to trap particles with arbitrary refractive indices.
► We introduce the concept of optical trapping for arbitrary refractive index media.
► Both the host medium and the particle may have a negative refractive index.
► They may be exploited in the future as auxiliary entities for trapping purposes.
► Extending the range of the refractive index extends the trapping possibilities.
► Interesting force profiles arise when the refractive index becomes negative.
Journal: Metamaterials - Volume 6, Issues 1–2, November 2012, Pages 51–63