Two-dimensional light diffraction from thin opal films

AbstractWe have produced lateral porosity modulation in porous silicon layers on a micron scale. Using the photosensitivity of the etching process and optical interferences, stripes are formed periodically on the top but also in the depth of the layer depending on the illumination wavelength. The periodicity of the structure is easily modified by changing the wavelength or the incident angles of the two laser beams used to create the modulated illumination. By rotating the sample, two dimensional structures have also been obtained. The samples formed by this procedure are characterised by light diffraction and photoluminescence both of which show the alternance of high and low porosity ranges. With this kind of in-depth lithography, easy and very cheap fabrication of porous silicon gratings promises a large potential range of applications of this material to integrated optics and photonics.

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Demonstration of light diffraction by a two-dimensional ultrasound structure in a liquid

Uspekhi Fizicheskih Nauk ◽

10.3367/ufnr.0109.197302k.0406 ◽

1973 ◽

Vol 109 (2) ◽

pp. 406

Author(s):

K.N. Baranskii ◽

G.A. Sever

Keyword(s):

Light Diffraction ◽

Two Dimensional

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Two-Dimensional Light Diffraction from an EPROM Chip

The Physics Teacher ◽

10.1119/1.5021429 ◽

2018 ◽

Vol 56 (2) ◽

pp. 70-71 ◽

Cited By ~ 3

Author(s):

Tom Ekkens

Keyword(s):

Light Diffraction ◽

Two Dimensional

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Spectrophotometric measurements of objective-prism spectra

Symposium - International Astronomical Union ◽

10.1017/s007418090005333x ◽

1966 ◽

Vol 24 ◽

pp. 118-119

Author(s):

Th. Schmidt-Kaler

Keyword(s):

Progress Report ◽

Two Dimensional ◽

Objective Prism ◽

Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

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Introductory paper

Symposium - International Astronomical Union ◽

10.1017/s0074180900053031 ◽

1966 ◽

Vol 24 ◽

pp. 3-5

Author(s):

W. W. Morgan

Keyword(s):

Line Intensity ◽

Classification Scheme ◽

Two Dimensional ◽

Spectral Classification ◽

Dimensional Array ◽

Rr Lyrae ◽

Metallic Line ◽

Introductory Paper ◽

Parameter Varying ◽

Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

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