Optical coating and apparatus including the optical coating

Abstract

An optical coating having a first wavelength region for optical heating and a second wavelength region for optical sensing is disclosed. A device that can include the optical coating is also disclosed. An optical system that can include the device and a light source is also disclosed. Additionally, methods of making and using the optical coating, the device, and the optical system are also disclosed.

Description

Related Applications

[0001] This application claims priority to U.S. Provisional Application No. 62 / 933,090, filed November 8, 2019, the disclosure of which is incorporated herein by reference in its entirety. [Technical field]

[0002] The present disclosure generally relates to optical coatings having a first optical wavelength range for optical heating and a second optical wavelength range for optical sensing. Apparatuses that can include the optical coatings are also disclosed. Optical systems that can include the apparatus and a light source are also disclosed. Methods of making and using the optical coatings, apparatus, and optical systems are also disclosed. [Background technology]

[0003] Optical systems, including external sensor windows such as Light Detection and Ranging (LIDAR), thermal imaging, and RGB cameras, are used in automobiles and are exposed to the external environment, such as ice and water (both large droplets such as fog and small droplets) that cause optical artifacts that destabilize the optical system.

[0004] For example, in LIDAR windows, resistive heating of an indium tin oxide (ITO) coating is used to provide effects such as heating, defogging, de-icing, etc. The ITO coating resides on the inner surface of a glass substrate. A resistive wire is typically used to connect to the ITO coating and to a bus bar. As a result, two potential problems arise. First, the connection between the resistive wire and the bus bar can break, making it an unreliable method for delivering heat to the ITO coating. Second, the heat generated by the heated ITO coating must be transferred through the bulk of the glass substrate, which is an inefficient means for thermal conduction.

[0005] What is needed is easy optical system level integration of optical coatings that are durable (eg, for repeated use in exterior environments) and efficient (eg, both cost and heat transfer). [Brief description of the drawings]

[0006] Features of the present disclosure are illustrated, and not limited, in the following figure(s), in which like numerals refer to like elements.

[0007] [Figure 1A] 1 is a graph illustrating the absorption and transmission characteristics of an optical coating according to an embodiment of the present invention. [Figure 1B] 4 is a graph illustrating the absorption and transmission characteristics of an optical coating according to another aspect of the present invention. [Figure 1C] 4 is a graph illustrating the absorption and transmission fabrication of an optical coating according to another aspect of the present invention. [Figure 1D] 4 is a graph illustrating the absorption and transmission characteristics of an optical coating according to another aspect of the present invention. [Figure 1E] 4 is a graph illustrating the absorption and transmission characteristics of an optical coating according to another aspect of the present invention. [Figure 1F] 4 is a graph illustrating the absorption characteristics of an optical coating according to another aspect of the present invention. [Figure 1G] 4 is a graph illustrating the transmission characteristics of an optical coating according to another aspect of the present invention. [Figure 2A] 1 is a schematic diagram of an apparatus according to an embodiment of the present invention. [Figure 2B] 2 is a schematic diagram of an apparatus according to another aspect of the present invention. [Figure 2C] 2 is a schematic diagram of an apparatus according to another aspect of the present invention. [Figure 3A] 1 is a schematic diagram of an optical system according to an aspect of the present invention. [Figure 3B] 2 is a schematic diagram of an optical system according to another aspect of the present invention. [Figure 3C] 1 is a schematic diagram of an optical system according to an aspect of the present invention. Summary of the Invention

[0008] In one aspect, an optical coating is disclosed having a first optical wavelength region for optical heating and a second optical wavelength region for optical sensing, the first optical wavelength region being different from the second optical wavelength region.

[0009] In another aspect, an apparatus is disclosed that includes a transparent substrate having a first side and a second side, and an optical coating disposed on the first side of the transparent substrate.

[0010] Additional features and advantages of various embodiments will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the various embodiments. The objectives and other advantages of the various embodiments will be realized and attained by means of the elements and combinations particularly pointed out herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] For the purpose of simplicity and illustration, the present disclosure is described mainly with reference to its examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be readily apparent that the present disclosure can be practiced without being limited to these specific details. In other examples, some methods and structures are not described in detail so as not to unnecessarily obscure the present disclosure.

[0012] Additionally, the elements depicted in the accompanying figures may include additional components, and some of the components depicted in those figures may be removed and / or modified without departing from the scope of the present disclosure. Additionally, the elements depicted in the figures may not be drawn to scale, and thus the elements may have a different size and / or configuration than that shown in the figures.

[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide an explanation of various embodiments of the present teachings. Disclosed herein in its broad and various embodiments are articles and methods of making and using the articles.

[0014] The present disclosure describes an optical coating 12 having a first optical wavelength region for optical heating and a second optical wavelength region for optical sensing. The first optical wavelength region can be different from the second optical wavelength region. For example, if the first optical wavelength region is the visible light region, the second optical wavelength region can be any other optical wavelength region, such as near infrared or near infrared and infrared. The dual region of the optical coating 12 allows the optical coating 12 to generate optical heat and provide optical sensing, such as those used in visible light imaging, thermal infrared sensing, and proximity sensing.

[0015] In one embodiment, the optical coating 12 can selectively absorb light in a first optical wavelength range for optical heating. The absorbed light can generate heat that can be used to heat the device 20 when exposed to an external environment. The first optical wavelength range can include the visible light wavelength range (350 nm to 780 nm), the near infrared light wavelength range, or a wavelength range including both visible light and near infrared light.

[0016] In some embodiments, the optical coating 12 can selectively transmit a second optical wavelength range for optical sensing. The selectively transmitted light can be sensed by a detector present in the optical system. The second optical wavelength range can include near infrared wavelengths, visible wavelengths (350 nm to 780 nm), short wave infrared wavelengths, or long wave infrared wavelengths.

[0017] As an example, optical coating 12 can include a first optical wavelength range, such as visible light, and a second optical wavelength range, such as near infrared, etc. Optical coating 12 can include silicon (such as a silicon-containing material, e.g., lanthanum silicon or hydrogen-doped silicon) as a light-absorbing material.

[0018] As shown in FIG 1A, the optical coating 12 can be an anti-reflective coating having an absorption characteristic (dashed line) in a first optical wavelength range of about 350 nm to about 780 nm and a transmission characteristic (solid line) in a second optical wavelength range of about 940 nm to about 1950 nm. In one embodiment, as shown in FIG 1B, the optical coating 12 can be an anti-reflective coating having an absorption characteristic (dashed line) in an optical wavelength range of about 350 nm to about 780 nm and a transmission characteristic (solid line) in an optical wavelength range of about 905 nm to about 1950 nm. In one embodiment, as shown in FIG 1C, the optical coating 12 can be an anti-reflective coating having an absorption characteristic (dashed line) in an optical wavelength range of about 350 nm to about 780 nm and a transmission characteristic (solid line) in an optical wavelength range of about 1550 nm to about 2150 nm. In one embodiment, as shown in FIG. 1D, optical coating 12 can be a bandpass coating having absorption characteristics in the optical wavelength range of about 350 nm to about 780 nm (dashed line) and transmission characteristics in the optical wavelength range of about 950 nm to about 1950 nm (solid line).

[0019] As an example, optical coating 12 can include a first optical wavelength range, such as near infrared or short wave infrared, and a second optical wavelength range, such as visible light. Optical coating 12 can include transparent conductive coatings, such as ITO and ITIO, instead of absorbing silicon (as in the example above) or in addition to silicon-containing materials, such as silicon dioxide.

[0020] As shown in FIG. 1E, optical coating 12 may be a broadband anti-reflective coating having absorption characteristics in the optical wavelength range of about 1000 nm to about 1850 nm (dashed line) and transmission characteristics in the optical wavelength range of about 350 nm to about 780 nm (solid line).

[0021] The first optical wavelength range and the second optical wavelength range can be customized for the optical system.

[0022] As an example, the optical coating 12 can include a first optical wavelength range, such as visible and near infrared light, and a second optical wavelength range, such as long wavelength infrared. The optical coating 12 can include germanium, which absorbs at wavelengths less than 1500 nm, and / or zinc sulfide. An optical coating 12 with germanium can typically absorb light less than 1800 nm. In comparison, silicon can typically absorb light less than 1000 nm. The optical coating 12 can absorb light through the second side 14 of the transparent substrate 10, such as silicon, when a light source 136 is disposed on the second side 14 of the device 20.

[0023] In one embodiment, optical coating 12 can be a long-wave infrared anti-reflective coating having absorption characteristics in the optical wavelength range of about 350 nm to about 1150 nm (dashed line in FIG. 1F) and transmission characteristics in the optical wavelength range of about 11000 nm to about 14500 nm (solid line in FIG. 1G).

[0024] The optical coating 12 can be matched to an optical system 100 having an absorbing light source 136 and a transmitting light source 140. In particular, the optical coating 12 can be formed of an absorbing material that absorbs light from an absorbing light source at the same wavelength, such as visible light. Non-limiting examples of absorbing materials that absorb visible light for use in the optical coating 12 include silicon-containing materials such as amorphous silicon, Si:H, Ge, Ge:H, SiGe, SiGe:H, and the like. Non-limiting examples of absorbing materials that absorb near infrared or short wave infrared light for use in the optical coating 12 include transparent conductive materials such as ITO, ITiO, ZnO, AlZnO, FTO, and carbon nanotubes.

[0025] Additionally, optical coating 12 may be formed of a transmissive material that transmits light from a transmissive light source at the same wavelength, such as near infrared light.

[0026] Optical coating 12 may be an anti-reflective coating. Optical coating 12 may also be a bandpass filter, a short wavelength pass filter, a long wavelength pass filter, a notch filter, a multi-band filter, or the like.

[0027] The optical coating 12 can be comprised of a single layer coating or a multi-layer coating. The optical coating 12 can include a single material having a first optical wavelength range and a second optical wavelength range. In an embodiment, the optical coating 12 can include a first material having a first optical wavelength range and a second material having a second optical wavelength range. The first material can be an absorbing material and the second material can be a transmitting material. Any and all combinations of materials and layers are contemplated.

[0028] In some embodiments, the optical coating 12 can be opaque at visible wavelengths, hi other embodiments, the optical coating 12 can include colorants such as dyes and pigments.

[0029] The optical coating 12 can be formed by a variety of processes. Non-limiting methods of manufacturing the optical coating 12 include DC magnetron sputtering, AC magnetron sputtering, pulsed DC sputtering, thermal evaporation, e-beam evaporation, CVD, PECVD, MOCVD, ion beam sputtering IBS, dual beam, and IBS, etc.

[0030] FIG. 2A illustrates an apparatus 20 comprising a transparent substrate 10 having a first side 16 and a second side 14 , and an optical coating 12 on the first side 16 of the transparent substrate 10 .

[0031] The transparent substrate 10 can be made of any transparent material. Non-limiting examples of transparent materials include glass, polymers, and resins. In an embodiment, the transparent substrate 10 can be tempered glass.

[0032] The first side 16 of the transparent substrate 10 may face an environment, such as an external environment that may have uncertain and unforeseen factors. These factors may adversely affect the ability of the device 20 to operate. For example, the first side 16 of the transparent substrate 10 may face an outside world having weather conditions, such as rain, wind, ice, snow, etc., and physical conditions, such as dirt, dust, insects, etc. The second side 14 of the transparent substrate 10 may face an indoor environment. For example, the second side 14 of the transparent substrate 10 may face an inside world, such as the inside of an automobile or a building.

[0033] It will be appreciated that because optical coating 12 may be present on first side 16 of transparent substrate 10, optical coating 12 may heat up faster as compared to optical coating 12 present on second side 14 of transparent substrate 10. In particular, because optical coating 12 may be present on first side 16 of transparent substrate 10, heat does not need to be transferred through transparent substrate 10.

[0034] 2B illustrates the device 20 further comprising a functional coating 18 on the optical coating 12. In one embodiment, the functional coating 18 can be a hydrophilic coating. In another embodiment, the functional coating 18 can be a hydrophobic coating. The hydrophobic coating 18 can be used to keep the device 20 clean, such as free from physical conditions such as dirt and dust. The functional coating 18 can be present on the second side 14 of the transparent substrate 10.

[0035] 2C illustrates the device 20 further comprising an internal optical coating 22 on the second side 14 of the transparent substrate 10. In some embodiments, the internal optical coating 22 can be a high performance anti-reflective coating. For example, the internal optical coating can be a broadband anti-reflective coating that selectively transmits visible light. In some embodiments, the device 20 does not include an indium tin oxide coating on the second side 14 of the transparent substrate 10.

[0036] The device 20 of the present disclosure can be an external sensor window. The device 20 can be used in a variety of applications, such as applications selected from automotive LIDAR, non-automotive LIDAR, auto RGB cameras (back-up cameras and advanced driver assistance cameras), surveillance cameras, perimeter control cameras, free space optical windows, thermal imaging windows, and directed energy windows.

[0037] FIG. 3A illustrates an optical system 100 comprising an apparatus 20 including a transparent substrate 10 having a first surface 16 and a second surface 14, and an optical coating 12 on the first surface 16 of the transparent substrate 10, and a light source 136.

[0038] The light source 136 can be any source capable of producing output illumination. Non-limiting examples of light sources include incandescent (W filament) bulbs (capable of producing both visible 350 nm to 780 nm and near infrared 800 nm to 2000 nm), LEDs (visible and NIR), quartz halogen, lasers (diode lasers, carbon dioxide lasers, etc.), glow bar heaters, flash lamps, pulsed lights, and the like. Pulsed light can limit interference between the light source 136 and the optical system (e.g., detect 90% of the time and heat 10% of the time). Additionally, for a fixed average delivered power, pulsed light can create a higher peak temperature in the optical coating 12. Pulse width modulation can vary the average applied power, which can be useful for temperature control. The light source 136 can be tailored to the absorption characteristics of the optical coating 12 to provide heating for anti-fog or de-icing processes.

[0039] The optical system 100 can include at least one absorbing light source 136 in a paraxial geometry, as shown in Figure 3A. In another embodiment, the optical system 100 can also include at least one light source 136 in a coaxial geometry, as shown in Figure 3B. In another embodiment, the optical system 100 can include a first absorbing light source 136 on the first side 16 of the device 20 and a second absorbing light source 136 on the second side 14 of the device 20, as shown in Figure 3C.

[0040] The optical system 100 can include two light sources, such as a first absorbing light source 136 that provides an absorbing wavelength of light to the optical coating 12 on the device 20, and a second transmitting light source 140 that provides a transmitting wavelength of light to the optical coating 12 on the device 20. In one embodiment, the optical system 100 can include a laser 140 and an incandescent light bulb 136. The optical system can also include a diffuser to collect light from the absorbing light source 136.

[0041] The optical system 100 can also include a detector 134. In some embodiments, the absorption light source 136 can be located between the transmission light source 140 and the detector 134. The optical system 100 can also include a telescope 132.

[0042] The optical coating 12 of the present disclosure can eliminate the need for using expensive ITO coatings on the device 20, such as on the second surface 14 of the transparent substrate 10. Additionally, the optical coating 12 can eliminate the need for bus bar electrical connections in the device 20 and / or the optical system 100.

[0043] The optical coating 12 may be disposed on the first side 16 of the transparent substrate 10, thereby allowing for the placement of an anti-reflective coating 22 on the second side 14 of the transparent substrate 10. The placement of the anti-reflective coating 22 on the inner surface of the device 20 may reduce back reflections into the optical system 100, such as a LIDAR system. One skilled in the art will appreciate that back reflections can generate spurious signals. Additionally, the placement of the optical coating 12 on the first side 16 of the transparent substrate 10 may allow for faster heating since heat transport through the transparent substrate 10 is eliminated.

[0044] A method of using the optical coating 12 comprises applying the optical coating 12 to a first side 16 of a transparent substrate 10 to form a device. The optical coating 12 can have a dual wavelength range of light such that the optical coating 12 can generate heat and provide optical sensing such as visible light imaging, thermal infrared sensing, and proximity sensing. As discussed herein, the optical coating 12 can selectively absorb light in a first optical wavelength range for optical heating. The absorbed light can generate heat that can be used to heat the device 20 exposed to an external environment. The optical coating 12 can selectively transmit light in a second optical wavelength range for optical sensing. The selectively transmitted light can be sensed by a detector present in the optical system.

[0045] A method of using apparatus 20 includes providing optical coating 12 on first surface 16 of transparent substrate 10 to form apparatus 20, and providing apparatus 20 to optical system 100. Optical coating 12, apparatus 20, and optical system 100 are as described above.

[0046] A method of using the optical system includes positioning an apparatus 20 having an optical coating 12 such that the optical coating 12 receives a first range of optical wavelengths from an absorbing light source and a second range of optical wavelengths from a transmitting light source. The optical coating 12, the apparatus 20, and the optical system 100 are as described above.

[0047] The optical coating 12 of the device 20 can be heated by light at a first wavelength from an absorbing light source. The heated optical coating 12 can defog the transparent substrate 10 of the device 20.

[0048] A method of using an optical coating comprises applying the optical coating of claim 1 to a first side of a transparent substrate. A method of using an apparatus comprises providing the optical coating of claim 1 to a first side of a transparent substrate to form an apparatus and providing the apparatus to an optical system. A method of using an optical system comprises positioning the apparatus of claim 9 such that the optical coating receives a first range of optical wavelengths from an absorbing light source and a second range of optical wavelengths from a transmitting light source. A method as claimed in claim 18, wherein the optical coating of the apparatus is heated by light of the first wavelength from the absorbing light source, and the heated optical coating defogs the transparent substrate of the apparatus.

[0049] From the foregoing description, those skilled in the art can appreciate that the present teachings can be implemented in a variety of forms. Thus, although these teachings have been described with reference to specific embodiments and examples thereof, the true scope of the present teachings should not be so limited. Various changes and modifications can be made without departing from the scope of the teachings herein.

[0050] The scope of the disclosure is to be broadly interpreted. The disclosure is intended to disclose equivalents, means, systems, and methods for achieving the coatings, devices, activities, and mechanical actions disclosed herein. For each coating, device, article, method, means, mechanical element, or mechanism disclosed, the disclosure is also intended to teach equivalents, means, systems, and methods for implementing the many aspects, mechanisms, and devices disclosed herein that are included within the disclosure. Furthermore, the disclosure is directed to coatings and their many aspects, features, and elements. Such coatings can be dynamic in their use and operation. The disclosure is intended to encompass equivalents, means, systems, and methods of use of the manufacturing device and / or manufacturing optical device and their many aspects that are consistent with the description and spirit of the operation and functions disclosed herein. The claims of this application are to be broadly interpreted as well. The description of the invention in its many embodiments herein is merely exemplary in nature, and thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations should not be considered as departing from the spirit and scope of the invention.

Claims

1. 1. An optical coating comprising: an absorbing material that absorbs a first light wavelength region for light heating; the optical coating transmits a second optical wavelength range for optical sensing; the first optical wavelength range is different from the second optical wavelength range; the first optical wavelength region is 350 nm to 780 nm; the optical coating is an anti-reflective coating; Optical coating.

2. 10. The optical coating of claim 1, wherein the second optical wavelength region is near infrared wavelengths.

3. 10. The optical coating of claim 1, wherein the first optical wavelength range further comprises near infrared wavelengths and the second optical wavelength range is long wave infrared wavelengths.

4. The optical coating of claim 1 , wherein the optical coating comprises a colorant.

5. 10. The optical coating of claim 1, wherein the optical coating comprises a single material that absorbs the first optical wavelength region and transmits the second optical wavelength region.

6. 10. The optical coating of claim 1, comprising a first material that absorbs the first optical wavelength region and a second material that transmits the second optical wavelength region.

7. a transparent substrate having a first surface and a second surface; an optical coating disposed on the first surface of the transparent substrate, the optical coating comprises an absorbing material that absorbs a first optical wavelength range for optical heating; the optical coating transmits a second optical wavelength range for optical sensing; the first optical wavelength range is different from the second optical wavelength range; the first optical wavelength region is 350 nm to 780 nm; the optical coating is an anti-reflective coating; Optical coatings; An apparatus comprising:

8. The apparatus of claim 7 further comprising a functional coating over the optical coating.

9. 9. The device of claim 8, wherein the functional coating is a hydrophilic coating.

10. 9. The device of claim 8, wherein the functional coating is a hydrophobic coating.

11. 8. The apparatus of claim 7, further comprising another optical coating on the second surface of the transparent substrate.

12. An apparatus according to claim 7; A light source; An optical system comprising:

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