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

Abstract

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.

Dual-Wavelength Pumped Dispersion-Compensating Fibre Raman Amplifiers

“…We have applied a random number generator to simulate relative and absolute errors of 0.25% and 1.5 nm, respectively in the layers of the filter depicted in Fig. 9. (These values significantly exceed the ones reported in Verly et al, 2002 andThelen et al, 2002. ) In this way we have simulated 100 fabricated filters for each of the two types of errors and we then selected the worst of each batch.…”

“…For that we need to supplement the matrix calculations with an optimisation procedure. The approach that we used is called the "needle method" (Tikhonravov et al, 1966;Sullivan and Dobrowolski, 1996;Thelen et al, 2001), which is a numerical technique that inserts a small needle into an empty or a given starting structure. The needle is a layer of a refractive index which is lower than that of the surrounding material.…”

“…The errors can be in the form of relative or absolute film thicknesses (Thelen et al, 2002). We have applied a random number generator to simulate relative and absolute errors of 0.25% and 1.5 nm, respectively in the layers of the filter depicted in Fig.…”

Multilayer thin-film coatings for optical communication systems

“…Dispersion compensation components are necessary for DWDM filters with bandwidths of 50-GHz and smaller [7]. Such compensation components can be realized by thin-film filters operated in reflection, since these are not minimum-phase filters and it is hence possible to design coatings with unity amplitude response and the desired phase characteristics.…”

“…A wide range of synthesis approaches is available to design multilayer coatings even with complex reflection and transmission profiles such as gain equalizing filters for erbium-doped fiber amplifiers (EDFAs) [1,5,6]. Recently, emphasis has been given to designing coatings with a decreased sensitivity to fabrication errors allowing a higher yield [7,8]. Progress has also been made in thermo-optic and electro-optic tuning of thin-film filters [9,10,11].…”