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J A Dobrowolski

Publications and source records attributed to J A Dobrowolski.

14 recordsLinked to original sources
PubMed2006

2004 Optical Society Of America's Topical Meeting on Optical Interference Coatings: Manufacturing Problem.

Results are presented for the second Optical Society of America's Optical Interference Coatings Manufacturing Problem. The participants were asked to produce multilayer coatings which, in the 450-650 nm spectral region and for light incident at 60 degrees, would have transmittances of 0.7 and 0.3 for p- and s-polarized light, respectively. Three different teams each submitted four solutions. Three different deposition processes were used to produce these coatings. The smallest average departure from the target transmission values was 0.79%. A number of interesting conclusions can be drawn from this exercise.

Journal Article↗
PubMed2006

Alfred Josef Thelen--on the occasion of his seventy-fifth birthday.

Alfred Thelen has made many very important contributions to the field of optical thin films. To honor him on the occasion of his 75th birthday, I prepared a bibliography of his many contributions for the ninth Topical Meeting on Optical Interference Coatings. Here an updated list of Alfred Thelen's books, chapters, papers, conference reports, and patents is presented.

Journal Article↗
PubMed2006

Philip Werner Baumeister (1929-2003): in memoriam.

Philip Baumeister pioneered the design of optical thin films by computer methods. He has published many important papers on various aspects of optical coatings, and he initiated the Optical Society of America's Topical Meetings on Optical Interference Coatings. Most important, during his time at the University of Rochester and thereafter, he trained and mentored generations of researchers and engineers in the theory and practice of thin-film interference coatings. Originally, a talk was prepared to celebrate his 75th birthday at the ninth Topical Meeting on Optical Interference Coatings. Because of his untimely demise on 22 October 2003, it was presented at the conference to honor his memory. This is a written version of the tribute that contains a comprehensive list of Philip Baumeister's various publications.

Journal Article↗
PubMed2006

Toward perfect antireflection coatings. 3. Experimental results obtained with the use of Reststrahlen materials.

The equipment and methods used to produce wide-angle antireflection coatings based on Reststrahlen materials are described. The optical constants of the coating materials used in the construction of the multilayers were determined by spectrophotometric ellipsometry and are compared with the literature values. The measured performance of an experimentally produced antireflection coating is compared with the expected calculated performance. The reflectance is low over a wide range of angles, but only in the narrow-wavelength region at which the refractive index of the Reststrahlen material is close to unity.

Journal Article↗
PubMed2004

Toward perfect antireflection coatings. 2. Theory.

Recently we performed a numerical investigation of antireflection coatings that reduce significantly the reflection over a wide range of wavelengths and angles of incidence, and we proposed some experiments to demonstrate their feasibility. We provide a theoretical description of omnidirectional antireflection coatings that are effective over a wide range of wavelengths.

Journal Article↗
PubMed2003

Ion-beam etching for the precise manufacture of optical coatings.

We propose using ion-beam etching as an additional tool for the accurate control of the thickness of thin films during the manufacture of sensitive optical multilayer coatings. We use a dual ion-beam sputtering system in the deposition and etch modes. In the deposition mode both the assist and sputtering ion beams are used to produce dense films at deposition rates in the range of 0.1-0.3 nm/s. In the etch mode, only the assist ion beam is used to remove material at a rate of less than 0.1 nm/s. A very high precision in the layer thicknesses can be obtained by alternating between deposition and etch modes. We observed that etching did not significantly affect the surface quality and the uniformity of the coatings. We introduced etching into our current manufacturing process and demonstrated its potential for the fabrication of several optical multilayer systems with performances that are very sensitive to the thickness of their layers.

Journal Article↗
PubMed2002

Topical meeting on optical interference coatings (OIC'2001): manufacturing problem.

Measurements are presented of the experimental filters submitted to the first optical thin-film manufacturing problem posed in conjunction with the Topical Meeting on Optical Interference Coatings, in which the object was to produce multilayers with spectral transmittance and reflectance curves that were as close as possible to the target values that were specified in the 400- to 600-nm spectral region. No limit was set on the overall thickness of the solutions or the number of layers used in their construction. The participants were free to use the coating materials of their choice. Six different groups submitted a total of 11 different filters for evaluation. Three different physical vapor deposition processes were used for the manufacture of the coatings: magnetron sputtering, ion-beam sputtering, and plasma-ion-assisted, electron-beam gun evaporation. The solutions ranged in metric thickness from 758 to 4226 nm and consisted of between 8 and 27 layers. For all but two of the samples submitted, the average rms departure of the measured transmittances and reflectances from the target values in the spectral region of interest was between 0.98% and 1.55%.

Journal Article↗
PubMed2002

Toward perfect antireflection coatings: numerical investigation.

A perfect antireflection (AR) coating would remove completely the reflection from an interface between two media for all wavelengths, polarizations, and angles of incidence. The degree to which this can be achieved is investigated numerically. It is shown that wideband solutions can be found provided that layers can be deposited with refractive indices that are close to that of the low-index medium. Thus realistic solutions exist for interfaces between two solid media. Narrow-band high-angle AR solutions are also possible for polarized light and for unpolarized light in the vicinity of certain reststrahlen bands.

Journal Article↗
PubMed1992

[Not Available].

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Anatomy↗
PubMed1991

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Anatomy↗
PubMed1986

[Not Available].

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History, Early Modern 1451-1600↗