HK40005107B - Angle of incidence restriction for optical filters - Google Patents
Angle of incidence restriction for optical filters Download PDFInfo
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- HK40005107B HK40005107B HK19128517.0A HK19128517A HK40005107B HK 40005107 B HK40005107 B HK 40005107B HK 19128517 A HK19128517 A HK 19128517A HK 40005107 B HK40005107 B HK 40005107B
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- optical filter
- filter
- incidence
- range
- angular displacement
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Description
Technical Field
The present application relates to optical filters.
Background
The coating system may be used to coat a substrate with a particular material. For example, pulsed Direct Current (DC) magnetron sputtering systems may be used for deposition of thin film layers, thick film layers, and/or the like. The optical element may be formed based on depositing a set of layers. For example, the thin film may be used to form a filter, such as an optical interference filter, a low angular displacement filter, a collimator, and/or the like. In some cases, the optical element may be associated with providing a particular function at a particular wavelength of light. For example, a band pass filter may be used to filter light in the near infrared range, light in the visible range, light in the ultraviolet range, and/or the like.
In an example, the light emitter may emit near-infrared light directed at the object. In this case, for the gesture recognition system, the light emitter may emit near-infrared light to the user, and the near-infrared light may be reflected from the user to the light receiver. The light receiver may capture information about the near-infrared light, and this information may be used to identify a gesture being performed by the user. For example, the device may use this information to generate a three-dimensional representation of the user and recognize a gesture being performed by the user based on the three-dimensional representation.
In another example, the information about the near-infrared light may be used to identify an identity of the user, a characteristic of the user (e.g., height or weight), a characteristic of another type of target (e.g., distance to the object, size of the object, shape of the object, spectral features of the object, or fluorescence of the object), and/or the like. However, ambient light may interfere with the near-infrared light during its transmission to the user and/or during its reflection from the user to the light receiver. Thus, the optical receiver may be optically coupled to an optical filter, such as a bandpass filter, a collimator, a low angular displacement filter, and/or the like, to allow near infrared light to pass toward the optical receiver. Similarly, the light receiver may be optically coupled to the aperture to limit stray light from passing to the light receiver.
Disclosure of Invention
According to some possible implementations, the composite optical filter may include a substrate. The composite optical filter may include a first component optical filter disposed on the substrate, where the first component optical filter is associated with a first angular shift. The composite optical filter may include a second component optical filter disposed onto the first component optical filter, wherein the second component optical filter is associated with a second angular displacement different from the first angular displacement, wherein the composite optical filter is configured to transmit light at a first range of angles of incidence and is configured to block light at a second range of angles of incidence different from the first range of angles of incidence.
According to some possible implementations, the optical system may include an optical filter including a plurality of component optical filters configured to filter the input optical signal and provide a filtered input optical signal, wherein the plurality of component optical filters are configured to block a first portion of the input optical signal that does not satisfy an angle of incidence threshold and pass a second portion of the input optical signal that satisfies the angle of incidence threshold. The optical system may include an optical sensor configured to receive the filtered input optical signal and provide an output electrical signal.
According to some possible implementations, the filter may include a first component filter associated with a first angular displacement and a first pass band. The filter may include a second component filter associated with a second angular displacement and a second passband, wherein the first angular displacement, the first passband, the second angular displacement, and the second passband are configured to cause the filter to transmit a spectral range of light at a first angle of incidence and to reflect the spectral range of light at a second angle of incidence.
1) The present application relates to a composite optical filter comprising:
a substrate;
a first component optical filter disposed on the substrate,
wherein the first component optical filter is associated with a first angular displacement; and
a second component optical filter disposed on the first component optical filter,
wherein the second component optical filter is associated with a second angular displacement different from the first angular displacement,
wherein the composite optical filter is configured to transmit light at a first range of angles of incidence and is configured to block light at a second range of angles of incidence different from the first range of angles of incidence.
2) The composite optical filter of 1), wherein the first range of angles of incidence is between about 0 degrees and about 30 degrees.
3) The composite optical filter of 1), wherein the first range of angles of incidence is between about 0 degrees and about 45 degrees.
4) The composite optical filter of 1), wherein the second range of angles of incidence is greater than about 30 degrees.
5) The composite optical filter of 1), wherein the second range of angles of incidence is greater than about 45 degrees.
6) The composite optical filter of 1), wherein the second range of incidence angles is between about 0 degrees and about 30 degrees, and wherein the first range of incidence angles is greater than about 30 degrees.
7) The composite optical filter of 1), wherein the composite optical filter transmits greater than a threshold percentage of light at the first range of angles of incidence, an
Wherein the threshold percentage is at least one of:
about 75% of the total weight of the composition,
about 90% of the total weight of the composition,
about 95%, or
About 99 percent of the total weight of the composition,
about 99.9% of the total weight of the composition,
about 99.99%, or
About 99.999%.
8) The composite optical filter of 1), wherein the composite optical filter is configured to block a threshold percentage of light at the second range of angles of incidence, an
Wherein the threshold percentage is at least one of:
about 75% of the total weight of the composition,
about 90% of the total weight of the composition,
about 95% of the total weight of the composition,
about 99 percent of the total weight of the composition,
about 99.9% of the total weight of the composition,
about 99.99%, or
About 99.999%.
9) The composite optical filter of 1), wherein the composite optical filter is configured to transmit light at a particular spectral range at the first range of angles of incidence and is configured to block light at the particular spectral range at the second range of angles of incidence.
10 The composite optical filter of 9), wherein the specific spectral range is at least one of:
between about 600 nanometers (nm) and about 1200nm,
between about 700nm and about 1100nm, or
Between about 800nm and about 1000 nm.
11 The composite optical filter of 9), wherein the specific spectral range is at least one of:
between about 1200 nanometers (nm) and about 2000nm,
between about 1400nm and about 1800nm, or
Between about 1500nm and about 1700 nm.
12 The composite optical filter of 9), wherein the specific spectral range is at least one of:
between about 200 nanometers (nm) and about 4000nm,
between about 1000nm and about 3000nm, or
Between about 1500nm and about 2500 nm.
13 The application relates to an optical system comprising:
an optical filter comprising a plurality of component optical filters configured to filter an input optical signal and provide a filtered input optical signal,
wherein the plurality of component optical filters are configured to block a first portion of the input optical signal that does not satisfy an angle of incidence threshold and pass a second portion of the input optical signal that satisfies the angle of incidence threshold; and
an optical sensor configured to receive the filtered input optical signal and provide an output electrical signal.
14 The optical system of 13), wherein a maximum transmittance of the optical filter is at a smaller angle of incidence than a minimum transmittance of the optical filter.
15 The optical system of 13), wherein a component optical filter of the plurality of component optical filters is a long pass (LWP) optical filter.
16 The optical system of 13), wherein a component optical filter of the plurality of component optical filters is a Short Wave Pass (SWP) filter.
17 The application relates to a filter comprising:
a first component filter associated with a first angular displacement and a first pass band; and
a second component filter associated with a second angular displacement and a second passband,
wherein the first angular displacement, the first pass band, the second angular displacement, and the second pass band are configured to cause the filter to transmit a spectral range of light at a first angle of incidence and to reflect the spectral range of light at a second angle of incidence.
18 The filter of 17), wherein the first angle of incidence is less than about 30 degrees and the second angle of incidence is greater than or equal to about 30 degrees.
19 17), wherein at least one layer of at least one of the first component filter or the second component filter is one of:
a material based on silicon (Si) and,
a material based on a silicon hydride is provided,
a germanium (Ge) -based material,
a germanium hydride-based material is provided,
a material based on aluminum (Al),
a material based on silver (Ag),
silicon dioxide (SiO) 2 ) The material(s) of which is (are),
aluminum oxide (Al) 2 O 3 ) The material(s) of the material(s),
titanium dioxide (TiO) 2 ) The material(s) of the material(s),
niobium titanium oxide (NbTiOx) material,
niobium tantalum pentoxide material (NbTa) 2 O 5 )，
A zinc oxide material (ZnO) is provided,
a material based on platinum (Pt) and,
a gold (Au) -based material that,
a silicon-germanium (SiGe) material is provided,
niobium pentoxide (Nb) 2 O 5 ) The material(s) of which is (are),
tantalum pentoxide (Ta) 2 O 5 ) A material, or
Magnesium fluoride (MgF) 2 ) A material.
20 17), wherein the filter is a collimator.
Drawings
FIG. 1 is a diagram of an overview of an example implementation described herein;
fig. 2A and 2B are diagrams of example implementations of optical filters described herein.
Fig. 3A-3E are graphs of example characteristics associated with the optical filters described herein.
Detailed Description
The following detailed description of example implementations refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.
The optical sensor device may include an array of sensor elements to receive light emitted from a light source (e.g., a light emitter, a light bulb, an ambient light source, and/or the like). For example, in a spectrometer, an optical sensor device may include an array of sensor elements to receive light reflected from a target object to enable identification of the target object. The sensor element may be associated with an optical filter that filters light to the sensor element to enable the sensor element to obtain information about a particular spectral range of electromagnetic frequencies. For example, the sensor elements may be aligned with optical filters having passbands in the Near Infrared (NIR) spectral range, the visible spectral range, the ultraviolet spectral range, and/or the like. The optical filter may include one or more layers to filter a portion of the light.
However, when the angle of incidence (AOI) of light directed toward the optical filter changes from a configured incidence (e.g., 0 degrees, 45 degrees, 90 degrees, etc.) to a threshold angle of incidence (e.g., a deviation from the configured incidence of greater than about 30 degrees), the filtering performance of the optical filter may degrade. In this case, the band edge may experience a blue shift to shorter wavelengths. Furthermore, polarization effects may become significant for the optical filter when the angle of incidence varies from a configured incidence (e.g., normal incidence, non-normal selected incidence, etc.) to a threshold angle of incidence (e.g., greater than a threshold effect level). The aperture may be disposed in alignment with the optical filter to limit the angle of incidence between the configured incidence and less than a threshold deviation from the configured incidence. In this way, effects produced by light directed to an optical filter or another type of optical element at angles of incidence greater than a threshold angle of incidence may be avoided.
However, the inclusion of the aperture may result in excessive cost of manufacturing the optical package including the optical filter and/or excessive package size for the optical package. Further, in some cases, it may be desirable to allow light having an angle of incidence greater than a threshold angle of incidence to be directed to the optical filter and to prevent light having an angle of incidence less than or equal to the threshold angle of incidence from being directed to the optical filter to perform field flattening. In this case, the field flattener may be optically coupled to an optical filter or another type of optical element. However, the inclusion of a field flattener lens may result in excessive size, cost, and/or manufacturing complexity for the optical package.
Some implementations described herein provide optical filters, optical devices, optical elements, optical modules, optical systems, and/or the like, wherein two optical filters are placed at a common substrate surface location to limit an angle of incidence of light. For example, the composite optical filter may include a first component optical filter that is a low angular displacement (e.g., less than a threshold angular displacement) optical filter associated with a first pass band and a second component optical filter that is a high angular displacement (e.g., greater than or equal to the threshold angular displacement) optical filter associated with a second pass band. In this manner, the composite optical filter may transmit light at configured angles of incidence and reflect or block light at angles of incidence greater than a threshold angle of incidence. In this manner, effects of angles of incidence greater than a threshold angle of incidence may be avoided without including an aperture, thereby reducing the cost, manufacturing complexity, size, and/or the like of an optical package including a composite optical filter. Optionally, based on configuring the pass bands of the component optical filters, the composite optical filter may be configured to block light at angles of incidence less than or equal to a threshold angle of incidence and pass light at angles of incidence greater than the threshold angle of incidence. In this manner, the composite optical filter may perform field flattening with reduced size, complexity, and/or cost relative to using a field flattener lens.
FIG. 1 is a diagram of an overview of an example implementation 100 described herein. As shown in fig. 1, the example implementation 100 includes a sensor system 110. The sensor system 110 may be part of an optical system and may provide an electrical output corresponding to the sensor decision. For example, the sensor system 110 may be part of a spectroscopy system, a gesture recognition system, an object recognition system, a motion tracking system, a communication system, and/or the like.
In some implementations, the sensor system 110 can include an optical filter structure 120 and an optical sensor 140, and the optical filter structure 120 can include a composite optical filter 130. In some implementations, composite optical filter 130 may include a set of component optical filters 130-1 and 130-2. For example, composite optical filter 130 may include a first component optical filter 130-1 that is a high angular displacement optical filter (e.g., an optical filter associated with an angular displacement greater than a threshold value) and a second component optical filter 130-2 that is a low angular displacement optical filter (e.g., an optical filter associated with an angular displacement less than or equal to a threshold value). In this manner, composite optical filter 130 may be configured to limit the angle of incidence at which incident light may pass through composite optical filter 130.
Although some implementations described herein may be described in terms of optical filters in a sensor system, some implementations described herein may be used in another type of system, in an optical system external to a sensor system, in an optical element of an optical package, and/or the like.
As shown in fig. 1 and further by reference numeral 150, the input optical signal is directed to the optical filter structure 120 at a set of angles of incidence. For example, the input optical signals 150-1 through 150-4 may be directed to the optical filter structure 120 at a set of angles of incidence. In this case, the input optical signal 150-1 may be directed at the optical filter structure 120 at the configured angle of incidence (N). Similarly, the input optical signals 150-2 and 150-3 may be at less than a threshold angle (e.g., less than θ) 0 ) Towards the optical filter structure 120. Conversely, the input optical signal 150-4 may be at an angle of incidence greater than or equal to a threshold angle of incidence (e.g., greater than or equal to θ) 0 ) Is directed towards the optical filter structure 120. In some implementations, the threshold angle of incidence can be related to a transmittance threshold. For example, a threshold angle of incidence may define the outputAngles at and/or above which the incoming optical signal is blocked or reflected, and when less than a threshold percentage of the incoming optical signal passes through the composite optical filter 130, the incoming optical signal may be referred to as being blocked or reflected.
As shown in fig. 1 and further by reference numeral 160, a first portion of the input optical signal is reflected by the optical filter structure 120. For example, based on the input optical signal 150-4 being directed at the optical filter structure 120 at an angle of incidence greater than or equal to a threshold angle of incidence, the composite optical filter 130 reflects the input optical signal 150-4. For example, an angular displacement of the pass bands of component optical filter 130-1 may cause the respective pass bands of component optical filter 130-1 and component optical filter 130-2 to be different such that input optical signal 150-4 is prevented from passing through composite optical filter 130, as described in more detail herein.
As indicated by reference numeral 170, the composite optical filter 130 and the optical filter structure 120 pass a portion of the optical signal. For example, the composite optical filter 130 passes the input optical signals 150-1 to 150-3 towards the optical sensor 140 based on the input optical signals 150-1 to 150-3 being directed to the optical filter structure 120 at less than a threshold angle of incidence. In some implementations, the composite optical filter 130 may be configured to block input optical signals associated with angles of incidence less than a threshold angle of incidence. For example, based on configuring the pass bands of component optical filters 130-1 and 130-2, composite optical filter 130 may be configured to block input optical signals 150-1 through 150-3 and pass input optical signal 150-4, as described in more detail herein.
As indicated by reference numeral 180, the optical sensor 140 may provide an output electrical signal for the sensor system 110 based on the portion of the optical signal that is communicated to the optical sensor 140. For example, the optical sensor 140 may provide an output electrical signal identifying the intensity of the light, a characteristic of the light (e.g., a spectral feature), the wavelength of the light, and/or the like. In this manner, composite optical filter 130 utilizes a high angular displacement filter and a low angular displacement filter to limit the angle of incidence with which light may pass through composite optical filter 130 without the use of apertures. In this manner, the cost, complexity, and/or size of the optical filter structure 120 and/or the sensor system 110 is reduced relative to using an aperture to limit the angle of incidence with which light may pass to the optical sensor 140.
As noted above, fig. 1 is provided as an example only. Other examples are possible and may differ from the example described with respect to fig. 1.
Fig. 2A and 2B are diagrams of an example optical filter 200/200'. As shown in fig. 2A, the optical filter 200 includes a substrate 210 on which a first component optical filter 220 and a second component optical filter 230 are disposed.
In some implementations, the first component optical filter 220 may be a low angular displacement filter. For example, the first component optical filter 220 may be a low angular displacement pass-band filter fabricated using a photopic coating based on silver (Ag). Additionally or alternatively, the first component optical filter 220 may be a low angular displacement bandpass filter fabricated using silicon hydride (Si: H). In some implementations, the first component optical filter 220 may be associated with less than a threshold angular displacement at greater than a threshold angle of incidence, as described in more detail herein. For example, the first component optical filter 220 may be associated with an angular displacement of less than 20%, less than 10%, less than 5%, less than 1%, and/or the like over a particular range of incident angles. In this case, the particular range of incident angles may be a range of about 0 degrees to about 60 degrees, about 0 degrees to about 45 degrees, about 0 degrees to about 30 degrees, and/or the like.
In some implementations, the first component optical filter 220 may be associated with less than a threshold thickness. For example, the first component optical filter 220 may be associated with a thickness of less than about 600 nanometers (nm), less than about 2000nm, less than about 5000nm, and/or the like. In some implementations, the first component optical filter 220 may be associated with multiple layers. For example, multiple layers may be deposited and/or patterned, e.g., using a photolithographic process, to form the first component optical filter 220. In some implementations, the optical filter 200 may be associated with a particular size. For example, the optical filter may be associated with a thickness between about 10nm and 5000nm, a length between 0.001 millimeters (mm) and 100mm, and/or a width between 0.01mm and 100 mm.
In some implementations, the second component optical filter 230 may be a high angular displacement filter. For example, the second component optical filter 230 may be a short wavelength pass high angular displacement filter. In some implementations, the second component optical filter 230 may be fabricated from a material having a refractive index less than a threshold refractive index. For example, the second component optical filter 230 may be silicon dioxide (SiO) based 2 ) Based on tantalum pentoxide (Ta) 2 O 5 ) And/or the like. In some implementations, the second component optical filter 230 may be associated with a threshold angular displacement. For example, the second component optical filter 230 may be associated with an angular displacement of greater than 1%, greater than 5%, greater than 10%, greater than 20%, greater than 30%, and/or the like over a particular range of incident angles. In this case, the particular range of incident angles may be between about 0 degrees and about 90 degrees, between about 10 degrees and about 60 degrees, between about 30 degrees and about 45 degrees, and/or the like. In some implementations, a particular range of incident angles may be greater than about 30 degrees, greater than about 45 degrees, and/or the like.
In some implementations, the second component optical filter 230 may be associated with less than a threshold thickness. For example, the second component optical filter 230 may be associated with a thickness of less than about 2500 nanometers (nm), less than about 3600nm, less than about 4000nm, and/or the like. In some implementations, the second component optical filter 230 may be associated with multiple layers. For example, a plurality of layers may be deposited and/or patterned, e.g., using a photolithographic process and/or the like, to form the second component optical filter 230.
In some implementations, the second component optical filter 230 may overlap the first component optical filter 220. For example, the second component optical filter 230 and the first component optical filter 220 may overlap at approximately the configured incidence, thereby enabling a portion of the light 240 to pass through to the substrate 210. In this case, for light associated with angles of incidence less than the threshold angle of incidence (e.g., rays 240-1 through 240-4), the light may pass through the first component optical filter 220 and the second component optical filter 230. In some implementations, the second component optical filter 230 and the first component optical filter 220 may partially overlap. For example, the second component optical filter 230 may cover a portion of the first component optical filter 220 that is aligned with a subset of the sensor elements of the array of sensor elements, and may not cover another portion of the first component optical filter 220 that is aligned with another subset of the sensor elements of the array of sensor elements. In this manner, the optical filter 200 may limit the angle of incidence of light directed to only a portion of the array of sensor elements.
In some implementations, at angles of incidence less than a threshold, greater than a threshold percentage of light may pass through the first and second component optical filters 220, 230. For example, for light having an angle of incidence of less than about 60 degrees, less than about 45 degrees, less than about 30 degrees, and/or the like, the first and second component optical filters 220, 230 may allow for greater than about 75% transmission, greater than about 90% transmission, greater than about 95% transmission, greater than about 99% transmission, greater than about 99.9% transmission, greater than about 99.99% transmission, about 99.999% transmission, and/or the like.
Conversely, for light associated with an angle of incidence greater than or equal to the threshold angle of incidence (e.g., rays 240-5 and 240-6), light may be prevented from passing through the first component optical filter 220 and the second component optical filter 230. In this case, the light may be reflected by the first and second component optical filters 220 and 230. In some implementations, less than or equal to a threshold percentage of light may be blocked by the first and second component optical filters 220, 230 at greater than or equal to a threshold angle of incidence. For example, for light having an incident angle of greater than or equal to about 30 degrees, greater than or equal to about 45 degrees, greater than or equal to about 60 degrees, and/or the like, the first and second component optical filters 220, 230 may be associated with a transmission of less than or equal to about 50%, a transmission of less than or equal to about 25%, a transmission of less than or equal to about 10%, a transmission of less than or equal to about 5%, a transmission of less than or equal to about 1%, and/or the like. In this case, optical filter 200 may block a threshold percentage of light, such as about 75%, about 90%, about 95%, about 99%, about 99.9%, about 99.99%, about 99.999%, and/or the like. In this manner, the use of a composite optical filter including a high angular displacement component optical filter and a low angular displacement component optical filter may eliminate the need for an aperture, thereby enabling reduced manufacturing complexity, reduced cost, reduced package size, and/or the like for the optical device.
In some implementations, the optical filter 200 may be associated with a particular spectral range for which the optical filter 200 will be transmissive at a first range of angles of incidence that satisfies an angle of incidence threshold and non-transmissive at a second range of angles of incidence that does not satisfy the angle of incidence threshold. For example, the optical filter 200 may be associated with a spectral range between about 600 nanometers (nm) and about 1200nm, about 700nm and about 1100nm, about 800nm and about 1000nm, and/or the like. Additionally or alternatively, the optical filter 200 may be associated with a spectral range between about 1200nm and about 2000nm, about 1400nm and about 1800nm, about 1500nm and about 1700nm, and/or the like. Additionally or alternatively, the optical filter 200 may be associated with a spectral range between about 200nm and about 4000nm, about 1000nm and about 3000nm, about 1500nm and about 2500nm, and/or the like. Additionally or alternatively, optical filter 200 may be associated with the visible spectral range, the near infrared spectral range, the ultraviolet spectral range, combinations thereof, and/or the like.
In some implementations, the optical filter 200 may include one or more other filters, such as blockers, edge filters, band pass filters, and/or the like. In some implementations, the optical filter 200 may include a protective covering (e.g., to protect the first component optical filter 220 and/or the second component optical filter 230 from environmental degradation). In some implementations, the optical filter 200 may include one or more layers of material. For example, optical filter 200 is for example the first component optical filter 220 or the second component optical filter 230 may include a silicon (Si) based material, a silicon hydride (Si: H) based material, a germanium (Ge) based material, a germanium hydride (Ge: H) based material, a silicon germanium (SiGe) based material, an aluminum (Al) based material, a silver (Ag) based material, a silicon dioxide (SiO) material 2 ) Material, alumina (Al) 2 O 3 ) Material, titanium dioxide (TiO) 2 ) Material, niobium pentoxide (Nb) 2 O 5 ) Material, tantalum pentoxide (Ta) 2 O 5 ) Material, magnesium fluoride (MgF) 2 ) Material, niobium titanium oxide (NbTiOx) material, niobium tantalum pentoxide material (NbTa) 2 O 5 ) A zinc oxide material (ZnO), a platinum (Pt) material, a gold (Au) material, and/or the like. In some implementations, the optical filter 200 may form a collimator.
As shown in fig. 2B, the optical filter 200' may allow light having an incident angle greater than or equal to a threshold angle to pass through, and may block light having an incident angle less than the threshold angle from passing through. For example, the optical filter 200 'may include a first component optical filter 220' and a second component optical filter 230 'disposed on the substrate 210'. The first component optical filter 220 'may be a low angular displacement filter and the second component optical filter 230' may be a high angular displacement filter. In this case, the first and second component optical filters 220', 230' may be configured such that the wavelength of light directed toward the optical filter 200 'is transmitted to the filter 200' at high angles of incidence (e.g., greater than or equal to a threshold angle of incidence) and reflected at low angles of incidence (e.g., less than the threshold angle of incidence). In this manner, optical filter 200 'achieves field flattening to reduce the intensity of light directed perpendicularly to optical filter 200'.
As indicated above, fig. 2A and 2B are provided as examples only. Other examples are possible and may differ from the examples described with respect to fig. 2A and 2B.
Fig. 3A-3E are graphical representations 300-360 of characteristics of optical filters described herein.
As shown in fig. 3A and by plot 300 and plot 310, the transmittance with respect to wavelength is determined for the high angular displacement component optical filter and the low angular displacement component optical filter at an incident angle of 0 degrees and an incident angle of n degrees, respectively. In some implementations, the long angular displacement component optical filter may be a long pass (LWP) component optical filter corresponding to the first component optical filter 220 of fig. 2A. In some implementations, the high angular displacement component optical filter may be a Short Wave Pass (SWP) component filter corresponding to the second component optical filter 230 of fig. 2A.
In some implementations, the pass bands of the high and low angular displacement component optical filters may be configured based on configured layer thicknesses, configured material types, and/or the like. The transmittance of the composite optical filter including the high angular displacement component optical filter and the low angular displacement component optical filter may be a product of respective transmittances of the high angular displacement component optical filter and the low angular displacement component optical filter. For example, the composite optical filter described with respect to fig. 3A may correspond to optical filter 200 of fig. 2A. In some implementations, a change in the angle of incidence can result in a change in the transmittance of the composite optical filter. For example, as shown, the composite optical filter may be associated with a reduced transmittance at an angle of incidence of n degrees (e.g., where n is greater than a threshold angle) relative to an angle of incidence of 0 degrees.
As shown in fig. 3B and by plots 320 and 330, the transmittance with respect to wavelength is determined for the high angular displacement component optical filter and the low angular displacement component optical filter at an incident angle of 0 degrees and an incident angle of n degrees, respectively. As shown, different passbands can be used to fabricate a composite optical filter to provide blocking of light at different angles of incidence. For example, in this case, the low angular displacement component optical filter is associated with a pass band different from that of the low angular displacement component optical filter of fig. 3A.
As shown in fig. 3C and by plot 340, with respect to angle of incidence (θ) AoI ) The intensity (I) of light passing through the composite optical filter of fig. 3A and/or the composite optical filter of fig. 3B is determined. For example, at the configured angles of incidence shown in diagrams 300 and 320, the intensity of light passing through the respective composite optical filter may be atAt a maximum (e.g., maximum transmittance), and at an angle of incidence greater than a threshold, as shown in graphs 310 and 330, the intensity of light may be less than the threshold. In this manner, the composite optical filter blocks light associated with angles of incidence greater than a threshold.
As shown in fig. 3D and by plots 350 and 360, transmittance with respect to wavelength is determined for the high angular displacement component optical filter and the low angular displacement component optical filter at an angle of incidence of 0 degrees and an angle of incidence of n degrees (e.g., where n is greater than a threshold angle). In some implementations, the long angular displacement component optical filter may be a long pass component optical filter corresponding to the first component optical filter 220' of fig. 2B. In some implementations, the high angular displacement component optical filter may be a short wave pass component optical filter corresponding to the second component optical filter 230' of fig. 2B. In some implementations, the passbands of the high and low angular displacement component optical filters may be configured based on configured layer thicknesses, configured material types, and the like. The transmittance of the composite optical filter including the high angular displacement component optical filter and the low angular displacement component optical filter may be a product of respective transmittances of the high angular displacement component optical filter and the low angular displacement component optical filter. For example, the composite optical filter described with respect to fig. 3D may correspond to optical filter 200' of fig. 2B. In this case, an angular displacement from 0 degrees to n degrees causes the transmittance of the composite optical filter to increase, based on the configuration of the respective component optical filters.
As shown in fig. 3E and by plot 370, transmittance with respect to wavelength is determined for the high angular displacement component optical filter and the low angular displacement component optical filter at different angles of incidence. In this case, the optical filter transmittance shifts to overlap with the low angular displacement component optical filter transmittance based on the high angular displacement component optical filter transmittance at the incident angle of n, the composite optical filter being associated with a transmittance greater than a threshold transmittance. Conversely, at the configured angle of incidence, the intensity of light passing through the composite optical filter may be at a minimum (e.g., minimum transmittance). In this manner, the composite optical filter blocks light associated with angles of incidence less than or equal to a threshold value.
As indicated above, fig. 3A-3E are provided as examples only. Other examples are possible and may differ from that described with respect to fig. 3A-3E.
In this way, (complex) optical filters comprising low angular displacement (component) optical filters and high angular displacement (component) optical filters enable angle of incidence limitation. For example, the optical filter may enable a threshold percentage of light to pass through the optical filter at the configured angle of incidence, and may block the threshold percentage of light at the threshold angle of incidence. In this manner, the optical filter eliminates the need for an aperture optically coupled to the optical device, thereby reducing the cost, complexity, and/or size of the optical device.
The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementations to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the implementations.
Some implementations are described herein in connection with thresholds. As used herein, meeting a threshold may refer to a value that is greater than the threshold, greater than or equal to the threshold, less than or equal to the threshold, and so forth.
Although particular combinations of features are set forth in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of possible implementations. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim appended may be directly dependent on only one claim, the disclosure of possible implementations includes each dependent claim in combination with every other claim in the set of claims.
No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more items, and may be used interchangeably with "one or more. Furthermore, as used herein, the term "set" is intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.), and may be used interchangeably with "one or more. Where only one item is intended, the term "one" or similar language is used. Further, as used herein, the terms "having", and the like are intended to be open-ended terms. Further, the term "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.
Claims (20)
1. A composite optical filter comprising:
a substrate;
a first component optical filter disposed on the substrate,
wherein the first component optical filter is associated with a first angular displacement,
wherein the first component optical filter is a low angular displacement bandpass filter fabricated using silicon hydride, si: H,
wherein the low angular displacement bandpass filter is associated with an angular displacement of less than 20% over a particular range of incident angles, an
Wherein the specific range of incident angles is a range of 0 degrees to 60 degrees;
a second component optical filter disposed on the first component optical filter,
wherein the second component optical filter is associated with a second angular displacement different from the first angular displacement,
wherein the composite optical filter is configured to transmit light at a first range of angles of incidence and is configured to block light at a second range of angles of incidence different from the first range of angles of incidence.
2. The composite optical filter of claim 1, wherein the first range of incident angles is between 0 degrees and 30 degrees.
3. The composite optical filter of claim 1, wherein the first range of incident angles is between 0 degrees and 45 degrees.
4. The composite optical filter of claim 1, wherein the second range of incidence angles is greater than 30 degrees.
5. The composite optical filter of claim 1, wherein the second range of angles of incidence is greater than 45 degrees.
6. The composite optical filter of claim 1, wherein the second range of angles of incidence is between 0 degrees and 30 degrees, and wherein the first range of angles of incidence is greater than 30 degrees.
7. The composite optical filter of claim 1, wherein the composite optical filter transmits greater than a threshold percentage of light at the first range of angles of incidence, an
Wherein the threshold percentage is at least one of:
75％，
90％，
95％，
99％，
99.9％，
99.99%, or
99.999％。
8. The composite optical filter of claim 1, wherein the composite optical filter is configured to block a threshold percentage of light at the second range of angles of incidence, an
Wherein the threshold percentage is at least one of:
75％，
90％，
95％，
99％，
99.9％，
99.99%, or
99.999％。
9. The composite optical filter of claim 1, wherein the composite optical filter is configured to transmit light at a particular spectral range at the first range of angles of incidence and is configured to block light at the particular spectral range at the second range of angles of incidence.
10. The composite optical filter of claim 9, wherein the particular spectral range is at least one of:
between 600 nanometers (nm) and 1200nm,
between 700nm and 1100nm, or
Between 800nm and 1000 nm.
11. The composite optical filter of claim 9, wherein the particular spectral range is at least one of:
between 1200 nanometers (nm) and 2000nm,
between 1400nm and 1800nm, or
Between 1500nm and 1700 nm.
12. The composite optical filter of claim 9, wherein the particular spectral range is at least one of:
between 200 nanometers (nm) and 4000nm,
between 1000nm and 3000nm, or
Between 1500nm and 2500 nm.
13. An optical system, comprising:
an optical filter comprising a plurality of component optical filters configured to filter an input optical signal and provide a filtered input optical signal,
wherein the plurality of component optical filters are configured to block a first portion of the input optical signal that does not satisfy an angle of incidence threshold and pass a second portion of the input optical signal that satisfies the angle of incidence threshold,
wherein the plurality of component optical filters include low angular displacement filters fabricated using silicon hydride, si: H,
wherein the low angular displacement filter is associated with an angular displacement of less than 20% over a particular range of incident angles, an
Wherein the specific range of incident angles is a range of 0 degrees to 60 degrees; and an optical sensor configured to receive the filtered input optical signal and provide an output electrical signal.
14. The optical system of claim 13, wherein the maximum transmittance of the optical filter is at a smaller angle of incidence than the minimum transmittance of the optical filter.
15. The optical system of claim 13, wherein the low angular displacement filter is a long pass (LWP) optical filter.
16. The optical system of claim 13, wherein the plurality of component optical filters further comprises a Short Wave Pass (SWP) filter.
17. A filter, comprising:
a first component filter associated with a first angular displacement and a first pass band,
wherein the first component filter is a low angular displacement filter fabricated using silicon hydride, si: H,
wherein the low angular displacement filter is associated with an angular displacement of less than 20% over a particular range of incident angles, an
Wherein the specific range of incident angles is a range of 0 degrees to 60 degrees; and a second component filter associated with the second angular displacement and a second passband,
wherein the first angular displacement, the first pass band, the second angular displacement, and the
The second passband is configured to cause the filter to transmit a spectral range at a first angle of incidence
And reflects light of the spectral range at a second angle of incidence.
18. The filter of claim 17, wherein the first angle of incidence is less than 30 degrees and the second angle of incidence is greater than or equal to 30 degrees.
19. The filter of claim 17, wherein at least one layer of the second component filter is
Tantalum pentoxide (Ta) 2 O 5 ) A material.
20. The filter of claim 17, wherein the filter is a collimator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62/618,372 | 2018-01-17 | ||
| US16/164,225 | 2018-10-18 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK40005107A HK40005107A (en) | 2020-04-29 |
| HK40005107B true HK40005107B (en) | 2023-04-06 |
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