OPTICAL CAMOUFLAGE FILTERS

• Main Authors: WHEATLEY, John A, DU, Guanglei, LV, Yi Hang, RENSTROM, Anthony M
• Format: Patent
• Language: English
• Published: 24.01.2019
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

A system may include one or both of a light emitter (46) and a light receiver (40), and an optical filter (10). The optical filter (10) includes a wavelength selective scattering layer (14). The wavelength selective scattering layer (14) may have a near-infrared scattering ratio of less than about 0.9. The filter (10) may have a visible reflective haze ratio of greater than about 0.5. A method may include disposing the wavelength selective scattering layer (14) adjacent one or both of the light emitter (46) and the light receiver (40). The optical filter (10) may include a wavelength selective reflective layer (16). The optical filter (10) may include a wavelength selective absorbing layer (34). An article may include the optical filter (10). The wavelength selective scattering layer (14) may have an average near-infrared scattering of less than 60%, an average visible scattering of greater than 10%, and a difference between the % total visible reflectance and the % diffuse visible reflectance of less than 20.