US 12,416,751 B2
Ultra wide band optical absorber based on multilayer transition metal layers
Cheng Zhang, Suzhou (CN); Xiaofeng Li, Suzhou (CN); Haoyu Li, Suzhou (CN); Binglin Huang, Suzhou (CN); Ti Sun, Suzhou (CN); and Qinhua Wang, Suzhou (CN)
Assigned to Soochow University, Suzhou (CN)
Filed by Soochow University, Suzhou (CN)
Filed on Jan. 9, 2023, as Appl. No. 18/094,412.
Claims priority of application No. 202210294478.4 (CN), filed on Mar. 23, 2022.
Prior Publication US 2023/0305205 A1, Sep. 28, 2023
Int. Cl. G02B 5/28 (2006.01); G02B 5/00 (2006.01)
CPC G02B 5/281 (2013.01) [G02B 5/003 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An ultra wide band (UWB) optical absorber based on multilayer transition metal layers, wherein a working band of the UWB optical absorber comprises one of a visible-near infrared band and a mid-infrared band, and the UWB optical absorber comprises: a substrate and a planar multilayer structure disposed on the substrate;
wherein the planar multilayer structure comprises a high reflecting metal film layer and at least three light absorbing thin film structures disposed on the high reflecting metal film layer; each of the at least three light absorbing thin film structures comprises a transition metal film layer and a dielectric film layer, and a thickness of the transition metal film layer is smaller than that of the dielectric film layer;
wherein a thickness of the UWB optical absorber is less than 3000 nanometers (nm);
wherein the working band of the UWB optical absorber is the mid-infrared band;
wherein the planar multilayer structure comprises three of the at least three light absorbing thin film structures, and the planar multilayer structure is configured as the high reflecting metal film layer, a seventh dielectric film layer, a fourth light absorbing thin film structure, an eighth dielectric film layer, a fifth light absorbing thin film structure, a sixth light absorbing thin film structure and a ninth dielectric film layer sequentially stacked in that order; and
wherein
a material of the seventh dielectric film layer is MgF2, and a thickness of the seventh dielectric film layer is in a range of 850 nm to 910 nm;
a material of a fourth transition metal film layer of the fourth light absorbing thin film structure is Ti, and a thickness of the fourth transition metal film layer is in a range of 15 nm to 20 nm;
a material of a fourth dielectric film layer of the fourth light absorbing thin film structure is MgF2, and a thickness of the fourth dielectric film layer is in a range of 900 nm to 1000 nm;
a material of the eighth dielectric film layer is tantalic oxide (Ta2O5), and a thickness of the eighth dielectric film layer is in a range of 120 nm to 160 nm;
a material of a fifth transition metal film layer of the fifth light absorbing thin film structure is Ti, and a thickness of the fifth transition metal film layer is in a range of 15 nm to 20 nm;
a material of a fifth dielectric film layer of the fifth light absorbing thin film structure is Ta2O5, and a thickness of the fifth dielectric film layer is in a range of 600 nm to 650 nm;
a material of a sixth transition metal film layer of the sixth light absorbing thin film structure is Ti, and a thickness of the sixth transition metal film layer is in a range of 4 nm to 5 nm;
a material of a sixth dielectric film layer of the sixth light absorbing thin film structure is silicon nitride (Si3N4), and a thickness of the sixth dielectric film layer is in a range of 750 nm to 850 nm; and
a material of the ninth dielectric film layer is MgF2, and a thickness of the ninth dielectric film layer is in a range of 800 nm to 900 nm.