title: Extra high reflection coating with negative extinction coefficient.
abstract: This Letter designed an extra high reflection filter by using multilayers with a negative k, commonly referred to as gain layers. The gain layer was fabricated by embedding CdS quantum dots in a dielectric layer. Experimental results indicated that the effective k value is around -0.0008. The associated optical and physical properties were also discussed. The application of gain layers is very forward-looking.
authors.affiliation: Department of Optics and Photonics, National Central University, Chung-Li 32001, Taiwan.
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chen
authors.forename: Cheng-Chung
authors.initials: CC
authors.lastname: Lee
authors.forename: Sheng-Hui
authors.initials: SH
authors.lastname: Chen
authors.forename: François
authors.initials: F
authors.lastname: Flory