Generic dark hollow beams using negative cones chemically etched in fiber tips

We report here the characteristics of dark hollow beams (DHBs) generated using negative micro-axicons fabricated via selective chemical etching process in the tip of optical fibers. The DHB output from the etched fibers were further manipulated to generate single and multiple period optical bottle beams, 0th- and 1st- order Bessel beams and astigmatic Bessel beams and beams with helical wavefront. Selective excitation of the guided modes in single and multimode optical fibers with V-numbers ranging from 2.405 - 5.69 are etched to different negative cone dimensions and are used to generate in a controllable way DHBs and related optical beams. Negative cones are etched in the fiber tips via selective chemical etching process wherein the different etch rates of the fiber core and cladding dopants and dopant concentration results in different cone angles and cone depths. Input laser beam guided through the optical fiber diffracts and refracts at the tip generating beams with one or many bright rings surrounding the dark central spot. By positioning the DHB in the front focal plane of a bi-convex lens we generate Bessel beams whose characteristics are compared with that generated using positive cone etched in the fiber tip and bulk axicon. Under certain excitation conditions we also observe helical wavefront DHBs with phase dislocation embedded in the beam.

[1]  M J Padgett,et al.  Generation of a beam with a dark focus surrounded by regions of higher intensity: the optical bottle beam. , 2000, Optics letters.

[2]  W Sibbett,et al.  Creation and Manipulation of Three-Dimensional Optically Trapped Structures , 2002, Science.

[3]  大津 元一,et al.  Near-field nano-optics : from basic principles to nano-fabrication and nano-photonics , 1999 .

[4]  B. Lü,et al.  Four-petal Gaussian beams and their propagation , 2006 .

[5]  M. Wei,et al.  Adjustable generation of bottle and hollow beams using an axicon , 2005 .

[6]  Generation of dark hollow beam by use of phase-only filtering , 2009 .

[7]  Jianping Yin,et al.  Chapter 3 - Generation of dark hollow beams and their applications , 2003 .

[8]  David L. Andrews,et al.  Structured Light and Its Applications: An Introduction to Phase-Structured Beams and Nanoscale Optical Forces , 2008 .

[9]  K. M. Tan,et al.  In-fiber common-path optical coherence tomography using a conical-tip fiber. , 2009, Optics express.

[10]  P. Dawson,et al.  Chemical etching of optical fibre tips--experiment and model. , 2000, Ultramicroscopy.

[11]  M. D. Angelisa,et al.  Axially symmetric hollow beams using refractive conical lenses , 2002 .

[12]  Paolo Di Trapani,et al.  Spiraling zero-order Bessel beam. , 2009, Optics letters.

[13]  Ulrich T. Schwarz,et al.  Propagation dynamics of phase dislocations embedded in a Bessel light beam , 2002 .

[14]  Y. Arakawa,et al.  Nearly diffraction-limited focusing of a fiber axicon microlens , 2003 .

[15]  Liu Nan,et al.  GENERATION OF DARK HOLLOW BEAMS AND THEIR APPLICATIONS , 2000 .

[16]  J. Garcia-Sucerquia,et al.  Optical tubular structures produced by diffraction of circular apertures , 2004 .

[17]  Yangjian Cai,et al.  Generation of a high-quality partially coherent dark hollow beam with a multimode fiber , 2008, 2008 IEEE PhotonicsGlobal@Singapore.