# US 11,079,616 B2 · Nanostructure-based optical limiters for facilitating aperture protection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,616 B2 - Document ID: US11079616B2 - Status: Granted - Kind: B2 - Application number: 15/715,090 - Filed: 2017-09-25 - Published: 2019-03-28 - Granted: 2021-08-03 - Earliest claimed: 2017-09-25 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Minas H. Tanielian - Web page: https://patentgrep.com/patent/US11079616B2 ## CPC - G02F 1/01: for the control of the intensity, phase, polarisation or colour (G02F1/29, G02F1/35 take precedence) - B64C 1/1484: {Windows (B64C1/1492 takes precedence)} - B64C 1/1492: {Structure and mounting of the transparent elements in the window or windscreen} - G02F 1/3523: {Non-linear absorption changing by light, e.g. bleaching} - G02F 1/0126: {Opto-optical modulation, i.e. control of one light beam by another light beam, not otherwise provided for in this subclass} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - B64C: AEROPLANES; HELICOPTERS ## Abstract Various techniques provide nanostructure-based optical limiters for facilitating aperture protection. In one example, a method includes receiving, via a first window, incident light on a solution, where the solution includes liquid medium, a gas dissolved in the liquid medium, and nanostructures in contact with the liquid medium. The method further includes generating heat in the liquid medium based on oscillations of a subset of the plurality of nanostructures in response to the incident light. The method further includes releasing at least a portion of the gas from the solution as gas bubbles in response to the generated heat. The method further includes scattering, by the released gas bubbles, the incident light to prevent the incident light from reaching a second window. Related systems and products are also provided. ## Claims ### Claim 1 A method comprising: receiving, via a first window, incident light on a solution, wherein the solution comprises a liquid medium, a gas dissolved in the liquid medium, a foaming agent mixed in the liquid medium, and a plurality of nanostructures in contact with the liquid medium, wherein the solution is between the first window and a second window hermetically sealed to the first window, and wherein at least one of the plurality of nanostructures comprises a shell and a core covered by the shell; generating heat in the liquid medium based on oscillations of a subset of the plurality of nanostructures in response to the incident light; releasing at least a portion of the gas from the solution as gas bubbles in response to the generated heat; and scattering, by the released gas bubbles, the incident light to prevent the incident light from reaching the second window. ### Claim 2 (depends on 1) The method of claim 1, wherein the plurality of nanostructures comprises nanostructures distributed in the liquid medium and/or on a surface of the first window in contact with the liquid medium. ### Claim 3 (depends on 1) The method of claim 1, wherein the generating comprises heating at least a portion of the liquid medium from a first temperature to a second temperature, the method further comprising dissolving the released gas back into the liquid medium as the portion of the liquid medium decreases from the second temperature toward the first temperature. ### Claim 4 (depends on 1) The method of claim 1, wherein the heat is generated in response to the incident light when the incident light has a frequency within a frequency range and has at least a threshold irradiance. ### Claim 5 (depends on 4) The method of claim 4, wherein the frequency range and threshold irradiance are based at least in part on a size and a shape of each of the plurality of nanostructures, wherein the frequency range encompasses a visible-light spectrum and/or an infrared spectrum, and wherein the threshold irradiance is 0.1 W/cm2. ### Claim 6 A system comprising: an optical device comprising: a first window configured to pass incident light; a second window hermetically sealed to the first window; a solution between the first window and the second window, wherein the solution comprises: a liquid medium; a plurality of nanostructures in contact with the liquid medium, wherein at least a subset of the plurality of nanostructures is configured to generate heat by oscillating in response to the incident light when the incident light has a frequency within a frequency range and has at least a threshold irradiance, and wherein the threshold irradiance is 0.1 W/cm2; a foaming agent mixed in the liquid medium; and a gas dissolved in the liquid medium, wherein at least a portion of the gas is configured to release from the liquid medium as gas bubbles in response to the generated heat, and wherein the released gas bubbles are configured to scatter the incident light to prevent the incident light from reaching the second window. ### Claim 7 (depends on 6) The system of claim 6, wherein the plurality of nanostructures comprises nanostructures distributed in the liquid medium and/or on a surface of the first window. ### Claim 8 (depends on 6) The system of claim 6, wherein the plurality of nanostructures comprises a plurality of nanopatterns on a surface of the first window configured to generate heat by oscillating in response to the incident light. ### Claim 9 (depends on 6) The system of claim 6, wherein the subset of the plurality of nanostructures is configured to heat at least a portion of the liquid medium from a first temperature to a second temperature via oscillations, and wherein the released gas is configured to dissolve in the liquid medium as the portion of the liquid medium decreases from the second temperature toward the first temperature. ### Claim 10 (depends on 6) The system of claim 6, wherein the frequency range encompasses a visible-light spectrum and/or an infrared spectrum. ### Claim 11 (depends on 6) The system of claim 6, wherein the first and second windows are transparent at least to visible wavelengths, and wherein the plurality of nanostructures comprises electrically conductive material. ### Claim 12 (depends on 11) The system of claim 11, wherein the plurality of nanostructures comprises a plurality of metal nanostructures, carbon nanotubes, or titanium nitride. ### Claim 13 (depends on 6) The system of claim 6, wherein the system is a vehicle, a sensor, or a wearable device, wherein the released gas is configured to scatter the incident light to prevent the incident light from reaching the second window to provide protection to one or more operators of the system and/or one or more components of the system. ### Claim 14 (depends on 13) The system of claim 13, wherein: the system is an aircraft vehicle; the system further comprises: a housing; and one or more engagement elements coupled to the housing and configured to receive the optical device; and the optical device provides a window structure configured to engage with the one or more engagement elements and selectively pass light into the aircraft vehicle. ### Claim 15 (depends on 6) A method of making the system of claim 6, the method comprising: forming the solution, wherein the forming comprises: dissolving the gas in the liquid medium; mixing the foaming agent in the liquid medium; and providing the plurality of nanostructures in contact with the liquid medium; providing the solution between the first and second window; hermetically sealing the first window to the second window; and engaging the first window and second window with one or more engagement elements configured to receive the optical device. ### Claim 16 (depends on 15) The method of claim 15, wherein the plurality of nanostructures comprises nanostructures distributed in the liquid medium and/or nanostructures formed on an inner surface of the first window. ### Claim 17 (depends on 6) The system of claim 6, wherein the gas comprises carbon dioxide or ammonia, and wherein the foaming agent comprises at least one of sodium dodecyl sulfate, a protein, or polypeptides. ### Claim 18 (depends on 6) The system of claim 6, wherein at least one of the plurality of nanostructures comprises a shell and a core covered by the shell. ### Claim 19 An aircraft vehicle comprising: an optical device comprising: a first window configured to pass incident light; a second window hermetically sealed to the first window; a solution between the first window and the second window, wherein the solution comprises: a liquid medium; a plurality of nanostructures in contact with the liquid medium, wherein at least a subset of the plurality of nanostructures is configured to generate heat by oscillating in response to the incident light, and wherein at least one of the plurality of nanostructures comprises a shell and a core covered by the shell; and a gas dissolved in the liquid medium, wherein at least a portion of the gas is configured to release from the liquid medium as gas bubbles in response to the generated heat, and wherein the released gas bubbles are configured to scatter the incident light to prevent the incident light from reaching the second window; a housing; and one or more engagement elements coupled to the housing and configured to receive the optical device, wherein the optical device provides a window structure configured to engage with the one or more engagement elements and selectively pass light into the aircraft vehicle. ### Claim 20 (depends on 19) The aircraft vehicle of claim 19, wherein the subset of the plurality of nanostructures is configured to generate the heat by oscillating in response to the incident light when the incident light has a frequency within a frequency range and has at least a threshold irradiance, wherein the frequency range encompasses a visible-light spectrum and/or an infrared spectrum, and wherein the threshold irradiance is 0.1 W/cm2.