US 12,105,020 B2
Gas lens filter systems and methods
Jonas Sandsten, Lomma (SE); and Sten Lindau, Täby (SE)
Assigned to FLIR Systems AB, Täby (SE)
Filed by FLIR Systems AB, Täby (SE)
Filed on Jun. 17, 2021, as Appl. No. 17/351,126.
Application 17/351,126 is a continuation of application No. PCT/US2019/063097, filed on Nov. 25, 2019.
Claims priority of provisional application 62/783,086, filed on Dec. 20, 2018.
Prior Publication US 2021/0310941 A1, Oct. 7, 2021
Int. Cl. G01N 21/3518 (2014.01); G02B 5/28 (2006.01); G02B 13/14 (2006.01)
CPC G01N 21/3518 (2013.01) [G02B 5/281 (2013.01); G02B 13/14 (2013.01); G01N 2201/0648 (2013.01); G01N 2201/0686 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A device, comprising:
a three-lens optical system comprising:
an objective lens element configured to receive and transmit infrared (IR) radiation from a scene, wherein the IR radiation from the scene includes a particular range of wavelengths corresponding to an absorption/emission spectrum or a transmission spectrum of a gas;
a subjective lens element; and
a spectral lens element disposed between the objective lens element and the subjective lens element, wherein the spectral lens element is configured to receive the IR radiation transmitted through the objective lens element, wherein the spectral lens element comprises:
a first interference filter disposed on a first surface of the spectral lens element that is configured to filter the IR radiation transmitted through the objective lens element to a narrower wavelength band that includes the particular range of wavelengths, and
a second interference filter on a second surface opposite the first surface that is configured to filter the IR radiation transmitted through the objective lens element to a second narrower wavelength band that includes the particular range of wavelengths.