A focused Ga+ ion beam is used to mill a multilevel spiral phase plate at an acceleration voltage of 30 kV. Circular spiral phase plate with eight levels is fabricated directly on an indium-tin-oxide coated glass plate. Scanning electron microscopy images demonstrate the realization of multilevel phase plate on glass plate using focused ion beam milling. © 2013 SPIE.

Shanti Bhattacharya

Department of Electrical Engineering

Anand Vijayakumar

ACCELERATION VOLTAGES

COATED GLASS

FOCUSED ION BEAM MILLING

Indium tin oxide

optical vortices

PHASE PLATE

Scanning electron microscopy image

SPIRAL PHASE PLATES

Focused ion beams

Glass

Nanotechnology

Precision engineering

Scanning electron microscopy

TIN OXIDES

TIN PLATE

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Fabrication of multilevel spiral phase plates by focused ion beam milling

Proceedings of SPIE - The International Society for Optical Engineering

The realization of spiral phase optical elements on the cleaved end of an optical fiber by focused ion beam milling is presented. A focused Ga ion beam with an acceleration voltage of 30 keV is used to etch continuous spiral phase plates and fork gratings directly on the tip of the fiber. The phase characteristics of the output beam generated by the fabricated structures measured via an interference experiment confirmed the presence of phase singularity in the output beam. The devices are expected to be promising candidates for all-fiber beam shaping and optical trapping applications. © 2016 Optical Society of America.

Optics Letters

Direct patterning of vortex generators on a fiber tip using a focused ion beam

A compact optics configuration for the generation of donut beams for trapping atoms at the micrometer scale using a multilevel spiral-phase Fresnel zone plate (FZP) and a semiconductor laser is proposed. A FZP is designed and a multilevel spiral phase is integrated into it. A spiral-phase FZP with a radius of 1 mm and with more than 1300 half-period zones is designed with multiple angular levels for integer and fractional topological charges, and the device is fabricated using electron-beam lithography direct writing. The performance of the device is evaluated, and the generation of symmetric and asymmetric donut beams is successfully demonstrated. © 2012 Optical Society of America.

Applied Optics

Design, fabrication, and evaluation of a multilevel spiral-phase Fresnel zone plate for optical trapping

Japanese Journal of Applied Physics

Patterning of Spiral Structure on Optical Fiber by Focused-Ion-Beam Etching

Microelectronic Engineering

Fabrication of a three-dimensional optical vortices phase mask for astronomy by means of electron-beam lithography

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures

Fabrication of spiral-phase diffractive elements using scanning-electron-beam lithography

Axicon lens on optical fiber forming optical tweezers, made by focused ion beam milling

Journal	Proceedings of SPIE - The International Society for Optical Engineering
ISSN	0277786X
Open Access	No