All-nanoparticle concave diffraction grating fabricated by self-assembly onto magnetically-recorded templates

L Ye,O T Mefford,T M Crawford,C Rinaldi,B Terry

doi:10.1364/oe.21.001066

Abstract

Using the enormous magnetic field gradients present near the surface of magnetic recording media, we assemble diffraction gratings with lines consisting entirely of self-assembled magnetic nanoparticles that are transferred to flexible polymer thin films. These nanomanufactured gratings have line spacings programmed with commercial magnetic recording and are inherently concave with radii of curvature controlled by varying the polymer film thickness. This manufacturing approach offers a low-cost alternative for realizing concave gratings and more complex optical materials assembled with single-nanometer precision.

Highlights

Diffraction gratings consisting of a large number of spaced parallel slits or grooves play an important role in many technologies, including spectroscopy [1], laser systems [2], and information communication [3], where, for example, gratings increase the capacity of fiber-optic networks using wavelength division multiplexing/demultiplexing [4]
We describe the nanomanufacture of diffraction gratings from cobalt
We have nanomanufactured an all-nanoparticle diffraction grating embedded in a flexible, curved, polymer thin film and demonstrated its performance in a calibrated optical spectrograph

Summary

Introduction

Diffraction gratings consisting of a large number of spaced parallel slits or grooves play an important role in many technologies, including spectroscopy [1], laser systems [2], and information communication [3], where, for example, gratings increase the capacity of fiber-optic networks using wavelength division multiplexing/demultiplexing [4]. Gratings have been fabricated using laser pulses to ablate metal nanoparticles or thin films, with interference to create the grating pattern [9,10,11]. Nanoparticle self-assembly has promise as a sustainable manufacturing technology for construction of complex patterns including linear chains, and close packed arrays [12]. Self-assembly has been used to create dynamic diffraction gratings in liquid from colloidal nanoparticles using electrophoresis [13]. Self-assembly via DNA and other surface anchoring techniques has been employed to pattern diffraction gratings on surfaces [14]. We describe the nanomanufacture of diffraction gratings from cobalt ferrite (CoFe2O4) nanoparticles that are first self-assembled onto magnetic disk drive substrates and are transferred as assembled to standalone, polymer thin films

Grating nanomanufacturing

Spectral measurement and calibration

Concave grating

Conclusion