Ultrafast-laser-written glass polarization converter inexpensively creates optical vortices

Ultrafast-laser-written glass polarization converter inexpensively creates optical vortices

Southampton, England--Glass optical elements with vortex-shaped nanogratings developed by scientists at the University of Southampton's Optoelectronics Research Centre (ORC) can change a laser beam by creating optical vortices--a property valuable for superresolution optics and optical manipulation, among other applications.1

The prototype optical vortex converter, which works at a 532 nm wavelength, takes incident circularly polarized light and converts it to radially or azimuthally polarized light, depending on whether the incident light has left- or right-handed circular polarization; other polarization tricks are also possible. Azimuthally polarized light can be used at a focus to create a ring-shaped particle trap.

Fabrication by direct laser writing
The monolithic space-variant polarization converters are fabricated by direct writing with 270 fs pulses of light at a 1030 nm wavelength from a femtosecond laser, which spontaneously forms nanogratings in the glass with directions that are based on the polarization of the ultrafast beam. THe gratings take the form of spiraling lines formed by strings of nanovoxels (volumetric nanopixels).

Previous research at the ORC showed that lasers with fixed polarization produce voxels consisting of a periodic arrangement of ultrathin (tens of nanometers) planes. By passing polarized light through such a voxel imprinted in silica glass, the researchers observed that it travels differently depending on the polarization orientation of the light. This "form birefringence" phenomenon is the basis of the new polarization converter. The advantage of this fabrication approach over existing methods for microscopy is that it is 20 times cheaper and it is compact.

"Before this we had to use a spatial light modulator based on liquid crystal which cost about £20,000," said Peter Kazansky, one of the researchers. "Instead we have just put a tiny device into the optical beam and we get the same result."

The researchers have also developed and adapted this technology for five-dimensional optical recording. "We have improved the quality and fabrication time and we have developed this five-dimensional memory, which means that data can be stored on the glass and last forever," said Martynas Beresna, lead researcher for the project. "No one has ever done this before." The researchers are working with the Lithuanian company Altechna to introduce this technology to the market.

REFERENCE:

1. Martynas Beresna et al., Applied Physics Letters 98, 201101 (2011).




Most Popular Articles

Webcasts

Femtosecond Lasers – Getting the Photons to the Work Area

Ultrashort-pulse lasers, both picosecond and femtosecond, are now available from a large number of manufacturers, with new players entering the field at a ra...

Ray Optics Simulations with COMSOL Multiphysics

The Ray Optics Module can be used to simulate electromagnetic wave propagation when the wavelength is much smaller than the smallest geometric entity in the ...

Multichannel Spectroscopy: Technology and Applications

This webcast, sponsored by Hamamatsu, highlights some of the photonic technology used in spectroscopy, and the resulting applications.

Handheld Spectrometers

Spectroscopy is a powerful and versatile tool that traditionally often required a large and bulky instrument. The combination of compact optics and modern pa...

Opportunities in the Mid-IR

The technology for exploiting the mid-IR is developing rapidly:  it includes quantum-cascade lasers and other sources, spectroscopic instruments of many...
White Papers

Accurate LED Source Modeling Using TracePro

Modern optical modeling programs allow product design engineers to create, analyze, and optimize ...

Miniature Spectrometers for Narrowband Laser Characterization

In less than 60 years, lasers have transformed from the imagined “ray gun” of science fiction int...

Improve Laser Diode Performance by Reducing Output Cable Inductance using Twisted Pair Cable

The intent of this article is to provide information regarding the performance of twisted pair ca...
Technical Digests

REMOTE FIBER-OPTIC SENSING: Data in abundance from difficult environments

The use of optical fibers to measure strain, temperature, and other parameters at desired points ...

SCANNERS FOR MATERIALS PROCESSING: Serving demanding applications

Galvanometer-based scanners are an essential component in laser-based materials-processing system...

OPTICAL COATINGS: Evolving technology produces new benefits

The antireflection, high-reflection, and/or spectral characteristics provided by optical coatings...

FREEFORM OPTICS: Top-notch capabilities lead to expanded possibilities

The use of free-form aspherical surfaces in an optical system can give it abilities impossible to...

Click here to have your products listed in the Laser Focus World Buyers Guide.

PRESS RELEASES

SCHOTT and Applied Microarrays Establish Distribution Partnership for NEXTERION® Products

01/22/2013 SCHOTT and Applied Microarrays, Inc. have established a partnership for the distribution of SCHOT...

SCHOTT North America and Space Photonics, Inc. Sign Exclusive Licensing Agreement for Covert Communications Technology

01/22/2013 WASHINGTON, D.C.—October 18, 2012—Space Photonics Inc. and SCHOTT North America, Inc. today annou...
Social Activity
  •  
  •  
  •  
  •  
Copyright © 2007-2015. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS