Designing and manufacturing of interference notch filter with a single reflection band

TL;DR

This paper presents a novel design for a single reflection band notch filter that combines specific fabrication techniques and anti-reflection layers to achieve narrow notch width, high reflection, and reduced manufacturing challenges, validated through environmental testing.

Contribution

The work introduces a notch filter design with improved characteristics using a simplified manufacturing process and anti-reflection layers, enhancing performance and environmental stability.

Findings

Achieved narrow notch width with maximum reflection.

Reduced pass-band ripples using anti-reflection layers.

Validated stability through environmental tests.

Abstract

Rugate, HL, and hybrid methods are used to design Notch Filters. Achieving a design that fits the notch characteristics of the filter and reducing transmission band ripples are the most influential factors in this topic. The ability of easy fabrication and choosing the right manufacturing method to have a notch filter with better characteristics should be noted. The main idea of this work is to design a notch filter structure with a narrow notch width and maximum reflection while reducing fabrication challenges. In addition, using anti-reflection layers in the outermost part of the designed structure, the pass-band ripples are reduced. In designed systems, various quarter-wave factors were used, which have less challenge in the manufacturing step. In addition, the stability of the deposition conditions and the density of the layers affect their quality and consequently the result of environmental tests. Therefore, the sputtering method with RF and DC sources is used to construct the designed structure. Finally, the samples were subjected to environmental tests such as abrasion, humidity, temperature, and adhesion. Some of the significant results of the manufactured single-band notch filter are presented.