Design of a wavelength-tunable optical tweezer using a graded-index multimode optical fiber

摘要

A wavelength-tunable Optical Fiber Tweezer (OFT) based on a Graded IndexMultimode Fiber (GIMF) with a flat endface is proposed. It is shown that thedesign can support a trapping position which is far from the tip of the GIMFcompared with other common optical tweezing methods, hence reducing thepossibility of a contact between the trapped particle and the fiber tip.Moreover, because of the wavelength dependence of the GIMF design parameterssuch the Numerical Aperture (NA), the trapping position can becomewavelength-dependent. Therefore, the trapping position can be tuned over a longrange using a common wave-length tunable laser. The proposed OFT differs fromprevious fiber-based demonstrations by using a flat-endface fiber making thefabrication and experiment quite easier than previously proposedtapered-endface OFTs.