Ultra-long light sheets via curved beam intercrossing

Enrique G Neyra,Óscar Martínez-Matos,Pablo Vaveliuk

doi:10.1364/osac.393073

Abstract

An approach to yield a planar light sheet with thickness below the Abbe’s diffraction limit over ultra-long propagation distances is presented. Such features emerge by an induced interference of the fields associated to the caustic branches of a cusp-type curved beam. The optical sheet width and length are dynamically tuned by just varying one parameter of the signal encoded in a spatial light modulator within a standard setup for curved beam generation. This light sheet possesses the following characteristics: a high length-to-width ratio, a width below the Abbe’s diffraction limit, reduced sidelobes, and very low spreading along the sheet length. These planar light sheets could be useful in light-sheet microscopy and applications to surface and interface physics. In addition, these sheets can be easily transformed in an optical needle having rectangular symmetry by using a two-dimensional cusp beam instead of an one-dimensional beam.

Highlights

An ultra-long optical needle is a beam that exhibits ultra-long light focus much grater than its cross-sectional dimension [1,2]
The optical razor blade” (ORB) performance as a function of α is centred on the behavior of the full width at half maximum (FWHM) of the intensity profile on-x-axis at the waist plane (z-position of largest intensity), namely ∆xw, and on the FWHM of the intensity along z-axis, namely ∆z
The Abbe’s diffraction limit for the top-hat beam, with dimension equal to the Spatial Light Modulator (SLM) aperture, passing through a cylindrical lens (1D rectangular symmetry) is given by the distance from the peak intensity to the first zero of the sinc-squared pattern that is the intensity of the 1-D top-hat Fourier transform

Summary

Introduction

An ultra-long optical needle is a beam that exhibits ultra-long light focus much grater than its cross-sectional dimension [1,2]. The central matter of these approaches was to achieve the greatest length-to-width ratio for the needle. This ratio acts as a figure of merit to evaluate the needle performance, achieving values from a few units to several orders of magnitude [12,13,15,16,18,19,20,21,22,24,25,26,27]. When an optical needle with thickness below the Abbe’s length is extended along one transverse axis, it becomes an “optical razor blade” (ORB), i.e. an ultra-long light sheet having a thickness below the Abbe’s diffraction limit

Methods

Results

Conclusion