Alfred Thelen

Nonpolarizing interference films inside a glass cube

The reflectance and transmittance of dielectric films at nonzero angle of incidence show strong polarization effects, and for many applications these effects are not wanted. Costich has recently published on the reduction of these effects in interference films. The extension of his theory to the case of a multilayer inside a glass cube is possible, but an efficient design does not result. In this paper another method using quarter-wave layers only is developed.

Circularly Wedged Optical Coatings. I. Theory

A method of depositing circularly wedged optical coatings is described and analyzed. Two rotating sector masks are placed between the substrate and the coating source. By proper control of the relative rotational speeds and the size of the sectors a selected variety of circularly wedged coatings can be generated. The outstanding feature of the generated thickness distributions is that the thickness changes linearly along a circular path. A theoretical analysis is made, a list of the various cases given, and the results are verified by using a photometric analog computer.

Topical Meeting on Optical interference Coatings (OIC’2001): design contest results

A gain-flattening filter (GFF) for minimum manufacturing errors (12 designs submitted) and dense wavelength-division multiplex (DWDM) filters for low group-delay (GD) variation (9 designs submitted) was the subject of a design contest held in conjunction with the Optical Interference Coatings 2001 topical meeting of the Optical Society of America. Results of the contest are given and evaluated. It turned out that the parameter space for GFFs with optimum performance when manufacturing errors are not considered is much different from that when manufacturing errors are considered. DWDM filter solutions with low GD variation are possible.

Design of a hot mirror: contest results

Various designs for a hot mirror to improve the efficacy of tungsten lamps are described. These designs were solicited at the 1995 Topical Meeting on Optical Interference Coatings.

Nonpolarizing edge filters: Part 2

By abandoning the concept of detuned Fabry-Perot interference filters for the design of nonpolarizing edge filters at oblique incidence and applying classical Herpin equivalent layer theory, the number of usable structures can be greatly expanded, and exact equations for aligning the edges in all cases can be derived.

Optical coating design algorithm based on the equivalent layers theory

New optical coating design algorithm with the equivalent layers theory is presented. The algorithm is based on the merit-function-constrained optimization in the accessible domain of equivalent phase thicknesses and equivalent refractive indices. It allows for creation of design coatings with sophisticated narrowband spectral characteristics. (

Thin film telecommunication filters: automated design and pre-production analysis of WDM filters

The combination of the integer optimization technique with ideas from classical design approaches results in an efficient automated approach to the design of WDM filters. An analysis of the pre-production manufacturing feasibility of different designs is addressed through numerical simulation of the deposition process.

Push-button technology in optical coating design : pro et contra

The progress in the design of optical coatings is essentially connected with the invention of the needle optimization technique and with the accumulated experience of its practical implementation. These factors enable raising a question about the developing of an entirely automated optical coating design technique. The presented paper discusses difficulties of the formalization of the design problem and the ways to overcome the intrinsic uncertainty of its formulation. It formulates the basic principles of implementation of the entirely automated design technique and considers the main pro et contra of the push-button design technology.

Phase properties of WDM filters

A simple relationship between the radiant energy transmittance and group delay in the passband region is established. This relationship is based on the consideration of complex poles of the amplitude transmittance.

Optical interference coatings: introduction by the feature editors

This introduction briefly reviews the history of the series of topical meetings on optical interference coatings and defines the scope of the features in this 15 July 1989 issue on the papers from the Fourth Topical Meeting.