WO2022074530A1

WO2022074530A1 - Selective optical collection devices and systems using same

Info

Publication number: WO2022074530A1
Application number: PCT/IB2021/059076
Authority: WO
Inventors: Doron Tzur
Original assignee: Maytronics Ltd.
Priority date: 2020-10-06
Filing date: 2021-10-04
Publication date: 2022-04-14

Abstract

A selective optical collection device (SOCD) and an optical system using a SOCD for optical enhancement of specific spatial areas and/or specific wavelengths. The SOCD including: a base structure with multiple optical pathways deployed over the base structure at different locations, wherein some of the optical pathways may have different characteristics such as different inclination angles and/or different dimensions and/or different optical properties, in respect to characteristics of other optical pathways. The differences in characteristics between the optical pathways, are designed for selective spatial collection of incoming light, such that more light passing through one or more optical pathways may be collected in respect to light passed through one or more other optical pathways. The system may also include an optical element configured for spectral diffraction and/or refraction of light before it is passed through the SOCD, for enabling selective spectral enhancement of light.

Description

Selective Optical Collection Devices and Systems Using Same FIELD OF THE INVENTION The present invention relates to optical systems and devices. More specifically, the present invention relates to methods, systems and optical devices that enable selective collection of light. BACKGROUND OF THE INVENTION A common type of spectrometers comprises an aperture or other means through which a polychromatic light beam is passed, a dispersing element, such as a diffraction grating or a prism which separates the polychromatic beam into essentially monochromatic beams, each moving in a slightly different direction typically angularly to one another, and an array of light sensitive elements for measuring the light intensity of each monochromatic beam. As the array of light sensitive elements all conventionally have about the same light sensitivity, it would be beneficial for the monochromatic beams impinging on them to have similar intensities. It would also be beneficial for the light sensitive elements sense essentially only light coming directly from the dispersing element rather than light coming from other directions. BRIEF DESCRIPTION OF THE FIGURES Fig. 1 shows a side view of a schematic illustration of an optical enhancement device, according to some embodiments; Fig.2 shows a frontal view of an optical enhancement device having tunnel shaped optical pathways, according to some embodiments; Fig. 3 shows a frontal view of an optical enhancement device having tapered slit shaped optical pathways, according to some embodiments; Fig. 4 shows a frontal view of an optical enhancement device having some optical pathways in a tunnel shape and some in a tapered slit shape, according to some embodiments; Fig.5 illustrates a net signal reaching a photodetector in a spectrometer and a signal reaching the photodetector after passing through the optical enhancement device of an embodiment of the present invention; Fig.6 is a magnified view of the signals shown in Fig.6 in a wavelengths range of between 190-250 nm ( low ultraviolet spectral region); Fig.7 shows differences in signal-to-noise ratio when using and when not using an optical enhancement device; Fig. 8 shows the expected improvement in accuracy of absorbance measurements when using the optical enhancement device of embodiments of the present invention. DETAILED DESCRIPTION OF SOME EMBODIMENTS Aspects of disclosed embodiments pertain to devices, systems and methods for selective spatial collection of light, e.g., for providing optimal light-collection of parts of an incoming light beam that are of lower intensity. According to some embodiments, there is provided a selective optical collection device (SOCD) including a base structure and multiple optical pathways deployed thereover. Each or some of the optical pathways may have different characteristics such as optical characteristics (opacity level) and/or geometrical characteristics such as different sizes, dimensions and/or orientation/inclination in respect to a main axis “x”. An optical pathway may include an open or partially transparent hole, channel, slit or tunnel of a specific tunnel/slit configuration, or an optical directing element such as a waveguide. According to some embodiments, the SOCD may be embedded or used as part of an optical system for spectral measurements of light emanating from a specific source or origin to be measured. This optical system may include an optical element such as an optical prism or a diffraction grating element, diffracting/refracting incoming light into multiple wavelengths (WLs) such that each WL or WL range (narrow WL band) is directed to propagate in a specific direction in respect to a main axis “x”. The SOCD may be positioned in relation to the positioning of the optical element and axis “x” such that each optical pathway thereof is positioned to collect light of a different WL thereby provide selective spectral and spatial light collection per WL/WL band. Intensities of monochromatic beams are highly dependent on properties of the light source used and/or on characteristics of a media through which the light emanating from the light source(s) is passed. Fig. 1 schematically illustrates an optical system 1000 for spatially and spectrally dependent collection of light, according to some embodiments, the optical system 1000 including: (i) an optical element such as a diffraction grating element 104 located and configured to diffract light emanating from a probed element such as from an illuminated liquid sample unit having a liquid sample held thereby, forming multiple monochromatic (spectrally differentiated) beam parts spatially and angularly separated from one another; (ii) a selective optical collection device (SOCD) 100 , including multiple optical pathways of different optical and/or geometrical characteristic such as different input and/or output apertures, for collecting different amounts of light therethrough; and (iii) a segmented detector 106, including, for example an array of optical sensors 106A- 106G. According to some embodiments, as shown in Fig. 1, the SOCD 100 includes multiple optical pathways such as different tunnels 102A-102G . Some of the pathways may be of a different characteristics than others depending on their location in respect to expected spectral and spatial distribution of wavelengths (herein spectral-spatial distribution) of light exiting the probed sample and passing through the diffracting optical element 104 (beam- part width/size and propagation angle/direction). The SOCD 100 may be configured and positioned (in respect to the diffraction grating optical element 104) such that intensities of wavelengths (of light exiting the sample and diffracted) that are to be enhanced will be passed through pathways of the SOCD 100 that have e.g., a larger aperture or more transparency for collecting more light of that specific wavelength (e.g. wavelengths (WLs) required for specific measurements, WLs that the light source outputs in low intensities and/or that are more absorbed by the sample) and WLs that are to be reduced in intensity (e.g. where light intensity is too high and therefore may saturate the sensor) will be passed through optical pathways that have a smaller aperture or that are more opaque. According to some embodiments, some of the optical pathways may be designed as a collimator or in a funnel shape for concentrating the collected light onto their respective segment of the segmented detector 106. As shown in Fig.1, each optical pathway (e.g.102A) is coupled at an output side thereof to a different segment/sensor of the segmented detector 106 (such as sensor 106A) for separate “per-channel” optical measurement. The SOCD 100 may be designed as a spectrum equalizer made of a light absorbing, reflecting or opaque material with multiple optical pathways such as optical tunneled optical pathways 102A-102G through which light passes and advances towards the different sensors 106A-106G of the segmented detector 106: 106A-106G. The tunneled optical pathways 102A-102G may be located over a strata material of the SOCD 110 that is made of an opaque or semi-transparent material for enabling all or most of the entring light to be optically directed mainly or exclusively through the optical pathways 102A- 102G. In accordance with some embodiments of the present invention, the SOCD 100 may be a spectral enhancement device for enhancing intensities of one or more wavelengths of the incoming light while reducing other wavelengths, depending on system requirements such as specific probed sample properties to be measured. In accordance with some embodiments of the present invention, enhancement of specific wavelengths in the UV and/or VIS may be carried out by the SOCD 100 for significantly improving the ability to measure light absorption properties of an illuminated water sample taken from a swimming pool and held in a cuvette, enabling, inter alia, to overcome or improve one or more of the following limitations: a. a light source of non-ideal spectrum used for illumination of the water sample such as a light source with strong emissions (high intensity) in some spectral regions and weak emission (low intensity) in the spectral regions of high interest such as spectral regions used for biological (algae) and/or chemical substances concentration such as ultraviolet (UV) and/or some regions of the visible (VIS) spectrum). b. low signal-to-stray light-ratio: Defined as a ratio between one or more parts of the optical spectrum considered as “stray light” and other parts of the spectrum . Stray light may be defined as light of the “wrong wavelength(s)” reaching some pixels of an optical sensor used to segmentally sense properties of light exiting the SOCD. The stray light may be diffused from surfaces of any of the sampling and/or optical elements of the system or directed due to imperfection in the diffraction/prism optical element or reflections from the sensor itself to the SOCD and back to the sensor. The stray light effect is significant when certain pixels/segments of the segmented detector 106 are weakly illuminated, e.g., due to enhanced absorption by the sample. Extraction of the actual spectral signal in the presence of stray light is complicated. c. widely varying specific absorptions of the sample have to be measured though the same cuvette. For example in pool water there is high absorption of pool water in several UV wavelengths e.g., an absorption rate of 99 percent or even more of the light in those specific wavelengths often due to presence/production of biological and/or chemicals such as Cyanuric acid, Normally occurring Organic Materials and nitrites having various absorption properties, whereas having a much lower absorbance in other wavelengths enabling 70 percent and more of the light to be transmitted. In accordance with some embodiments of the present invention, the position of each of the optical pathways 102A-102G with respect to a diffraction grating optical element 104 is different, and since all optical tunnels 102A-102G point to the diffraction grating 104, the optical axis of each of the optical tunnels 102A-102G has a different angle with respect to the diffraction grating optical element 104. Thus, by virtue of their location and inclination angle with respect to the diffraction grating 104, the tunnels 102A-102G minimize the passage of undesired wavelength(s) by allowing only specific predefined wavelength(s) to pass through and proceed towards the sensor elements. In addition, the SOCD 100 can minimize the amount of stray light reaching the sensor pixels 106A-106G from directions other than that of the diffraction grating 104 – much less light not originating in the diffraction grating 104 can reach the segments 106A-106G of the segmented detector 106. In accordance with some embodiments of the present invention, a highly important feature of the spectral enhancement device 100 is the ability to control the relative amount of light passing through and reaching each one of sensor pixels 106A-106G. This is done by spectral equalization, e.g., by controlling the width of the tunnel and/or its opacity, so that, each of the multiple tunnels 102A-102G may have a different width and/or opacity. In addition, controlling the width of the tunnel greatly improves stray light rejection - the improvement ratio depends on the geometry of the device 100 and on the fraction of stray light originating not from the diffraction grating optical element 104. In addition, the SOCD 100 enables selective reduction of the amount of light in regions having high amount of light, thus, reducing the amount of stray light that passes through and reaches the sensor pixels from reflections in other pixels. In accordance with the present invention, the SOCD 100 is designed to have wider tunnels in specific wavelengths areas (e.g. the low UV) to allow a greater amount of these wavelengths to pass through and narrower tunnels in areas of other wavelengths. Such design permits higher lighting or longer exposure times to get meaningful signals in low light areas while avoiding light saturation in other areas. In addition, such design further improves the system's ability to measure spectra with light sources of non-ideal spectrum. In accordance with some embodiments of the present invention, the width of each of optical pathways 102A-102G may be large enough to allow light to pass through and reach several sensor pixels. Alternatively, the width of the tunnel may restrict light to reach a single sensor pixel as seen in the figure. In accordance with some embodiments of the present invention, the optical pathways 102A-102G may all have same inclination angle with respect to a main axis “x” aligned with the diffraction grating optical element 104 differing from one another only by their geometrical dimensions (aperture width, size, shape, etc.) have the same geometrical dimensions but differ only in their inclination angles in respect to axis “x”, differ only in their optical properties or differ from one another in any combination of geometry, optical properties, and inclination. According to some embodiments, each tunnel optical pathway may have an internal optical coating such as a reflective, opaque, or refractive coating for further selectively controlling the collection of light arriving therethrough. A specific coating to a tunnel may determine the amount of light passing through and/or the light wavelength(s) that can pass through. In accordance with some embodiments of the present invention, each of optical pathways 102A-102G may have a different shape and width. In addition, some or all of the tunnels may be combined into a variable width slit. [0001] According to some embodiments, the optical system 1000 may further include a processing unit 120 for receiving and analyzing data arriving from the segmented detector 106 e.g., for determining water quality related properties, in cases in which the light passed through the optical element 104 emanates from a water/liquid sample that is illuminated by a light source. For example. The sample may be illuminated by light in the ultraviolet and/or visible spectral ranges and may be illuminated by a narrowband or broadband light source, depending on the specific property(ies) to be measured. [0002] Analysis and/or measured results may be: stored via one or more data storage units, displayed to users via one or more display devices, further analyzed, sent to one or more users, used for alerting events/conditions identification and alerting, and/or for automatic control of devices of a water/liquid facility associated with the water/liquid sample, e.g. for maintenance and/or repairing of impairments in the water/liquid facility. Fig. 2 illustrates a first example of a SOCD 200 comprised of a set of tunnel optical pathways, such as tunnels 202A, 202B and 202C, having different widths and shapes for determining the amount of light passing through. Fig. 3 illustrates an SOCD 300, according to another embodiment, where the SOCD 300 comprises a variable width slit 342. Seen in the figure, section 344 of the variable width slit 342 is fairly wide and thus allows a relatively high amount of light to pass therethrough. However, the gradual decrease in width in section 346 of the slit 342 causes a gradual decrease in the amount of light passing through. Fig.4 illustrates an SOCD 400 according to another embodiment, this SOCD 400 having a combined configuration. It has a tapered slit 410 formation in which the pathways of a first part of the SOCD 400 have output and/or input apertures that are gradually narrowed and a set of tunnel optical pathways 420, located at another side of the SOCD 400 As shown in Fig. 4, such configuration entails both gradual and abrupt decreases in light collection, i.e., a first section 411 of the variable width slit 410 allows a relatively high amount of light to pass through, while a second section 412 of the variable width slit 410 allows a gradual decrease in the amount of light passing through, and the set of tunnels 284 allows a much lower amount of light to pass through. Fig.5 illustrates a net signal 502 reaching a photodetector in a spectrometer and a net signal 504 reaching the photodetector after passing through the SOCD 100 of the present invention. It is understood that when using the SOCD 100, there is a need for an overall greater amount of light. For the purpose of comparison, signal 504 was normalized based on peak 506 of signal 502. As seen in the figure, when using the SOCD100, the portion of the signal 504 in the low UV is still low. This is due to realistic limitations of hole sizes which were taken into account in the simulation. However, as seen below in Fig. 6, such low values are significantly higher than the values obtained in the absence of the SOCD 100. Fig.6 is a magnified view of the signal 602 and the signal 304 in the low UV section. As seen in the figure, although signal 604 is relatively low in the low UV section, it is higher than signal 602. Fig. 7 shows the impact of the SOCD100 on reducing stray light. Fig.6 shows stray light to signal ratio profiles when using the SOCD 100 and when not using an SOCD 100 between a diffraction grating optical element and an optical detector: In the absence of the SOCD 100, stray light to signal ratio profile 702 is obtained, where stray light dominates the signal by a factor reaching more than ten. In contrast, when the SOCD 100 is used, a substantially better stray light to signal ratio profile 704 is obtained, the stray light is lower than the true net signal by a factor of about 10 at the very least. It should be noted that the simulation is based on the assumption that stray light is completely diffused and equal amount of stray light, with respect to the total light intensity, imping on each sensor element. In accordance with the present invention, the SOCD 100 geometrically decreases the amount of stray light and the degree of reduction depends on the tunnel pathway size. On the other hand, a greater amount of light is needed to achieve similar readings. In this example, the combined influence of both factors results in the need to have a significantly greater amount of light. This can often be achieved by simply removing a natural density (ND) filter or a small aperture that is often used to limit the light entering the spectrometer. Fig. 8 shows an expected improvement in accuracy of absorbance measurements when using the SOCD 100 of embodiment(s) of the present invention. Seen in the figure, curve 802 corresponds to true absorbance in pool water, curve 804 corresponds to absorbance measured in the absence of the SOCD 100, and curve 806 corresponds to absorbance measured in the absence of the SOCD 100. As seen in Fig.8, when absorbance measurements are conducted without the SOCD 100, the error in the absorbance measurement reaches as high as 1.3 AU. In contrast, when using the SOCD 100 in absorbance measurements, the maximal error goes down to 0.05 AU. Fig. 9 shows a SOCD 90 having multiple optical pathways of different shapes and sizes, according to some embodiments, where each segment/area of segments S₁₁-S₄₆ of the SOCD 90 includes a different number of optical pathways and/or optical pathways of different optical characteristics and/or dimensions. For example, segment S11 may include five small tunnels 911 (e.g., of 1-5nm in diameter or maximal width) as five optical pathways, while segment S42 may include two tunnels of a much larger apertures than that of the tunnels 911 of segment S₁₁. Each group of one or more optical pathways located in each segment may be designed to be directed to an area or to one or more pixels of an optical detector located in alignment with the SOCD 90. For example, the dimensions and locations of the optical pathways of the entire SOCD 90 may be designed to have a maximal coverage of the optical detector’s input area in order to optimize the optical detector’s spatial resolution and separation. Fig. 10 shows a SOCD 70 having multiple optical pathways of different shapes and sizes, according to some embodiments. The SOCD 70 may have different areas such as Areas A₁₁, A₁₂, A₁₃, A₂₁, A₂₂, A₂₃ and A₂₄, of different sizes. For example area A₁₁ may include an optical path having an elongated tapered aperture (e.g., having a trapeze shape), while A₁₂ is of a much smaller area-size having a single optical path of a much smaller rounded aperture. A24, for example, may include several dozens of optical paths having equal apertures of a microscopic size. The main objective to the variations in characteristics of the different optical paths of the SOCDs of embodiments of the present invention is, as mentioned above, to control amount and optionally other features of collected light per area of the SOCD such that some areas of the SOCD will be designed to collect more light than others (e.g. for selective spatial and spectral light-collection). In some embodiments, for easy and inexpensive production of SOCDs, the optical pathways of an SOCD may all be of the same characteristics (shape, size, tunnel length, optical characteristics, aperture size etc.), where the density and number of optical pathways may vary over the different segments/areas of the SOCD. This may enable using a single apparatus to form the optical pathways over a strata material forming the SOCD (e.g. by punctuating the SOCD strata) yet still enable some areas of the SOCD to collect more light than other areas of the SOCD. EXAMPLES: Example 1 is a selective optical collection device (SOCD) comprising: a base structure; and multiple optical pathways located over the base structure, wherein at least one of the optical pathways of the SOCD is different in one or more of its characteristics in respect to characteristics of at least one other optical pathway of the SOCD, the optical pathway characteristics being associated at least with geometrical dimensions of each optical pathway, inclination angle of each optical pathway, and/or one or more optical properties, and wherein differences in characteristics of at least some of the optical pathways, are designed for selective spatial collection of incoming light, by allowing collecting more light passed through one or more of the optical pathways in respect to light passed through one or more other optical pathways. In example 2, the subject matter of example claim 1 may include, wherein the one or more characteristics of the optical pathways further comprise at least one of: dimensions, size, shape, tilt angle relative to the optical axis, optical characteristics, input and/or output aperture shape and/or size. In example 3, the subject matter of any one or more of examples 1 to 2 may include, wherein the base structure is made from an opaque, light-absorbing, reflective, semi- reflective and/or semi-transparent material. In example 4, the subject matter of any one or more of examples 1 to 3 may include, wherein each optical pathway is shaped as a cylindrical tunnel, a tapered tunnel, a tapered slit, and forms a hole inside the base structure, such as to enable light incoming from one side of the optical enhancement device to be directed such that it exits another side of the optical enhancement device. In example 5, the subject matter of any one or more of examples 1 to 3 may include, wherein each optical pathway is an optical waveguide, such as to enable light incoming from one side of the optical enhancement device be directed such that it is directed to exit another side of the optical enhancement device. In example 6, the subject matter of any one or more of examples 1 to 5 may include, wherein the SOCD is positioned in relation to a segmented detector such that each segment of the segmented detector is configured and positioned to detect optical characteristics of light exiting from a different area or optical pathway of the SOCD. In example 7, the subject matter of example 6 may include, wherein the segmented detector comprises: an array of optical sensors or a pixelated optical detector, wherein each sensor in the sensors array or each pixel of the pixelated detector is coupled or located in proximity to a different output side of a specific optical pathway, from which light exits. In example 8, the subject matter of any one or more of examples 1 to 7 may include, wherein the SOCD is located in a specific position in respect to an optical element, the optical element being located and configured to spectrally refract or diffract light passing therethrough such as to form multiple monochromatic output beams exiting the optical element, wherein optical pathways of the SOCD are located and configured for optimal collection of a specific monochromatic beam emanating from the optical element, based on expected intensity, directionality and/or WL of the respective monochromatic beam. In example 9, the subject matter of example 8 may include, wherein the optical element is a diffraction grating optical element or an optical prism. In example 10, the subject matter of any one or more of examples 8 to 9 may include, wherein the light illuminating the optical element emanates from a water sample being illuminated by at least one light source, for optical measurements of the water sample. In example 11, the subject matter of any one or more of examples 1 to 10 may include, wherein the density of optical pathways per area or segment of the SOCD varies between different areas/segments. Example 12 is an optical system comprising at least: an optical element configured for spectral diffraction and/or refraction of light; and a selective optical collection device (SOCD) comprising: (i) a base structure; and (ii) multiple optical pathways deployed over the base structure at different locations, wherein at least one of the optical pathways has one or more different characteristics in respect to geometrical characteristics of at least one other optical pathway of the SOCD, the characteristics comprising at least inclination angle of the respective optical path, in relation to a main axis, wherein the differences in characteristics of at least some of multiple optical pathways, are designed for selective spatial collection of incoming light. In example 13, the subject matter of example 12 may include, wherein the one or more characteristics of the optical pathways of the SOCD further comprise at least one of: dimensions, size, optical characteristics, input and output aperture sizes. In example 14, the subject matter of any one or more of examples 12 to 13 may include, wherein the base structure of the SOCD is made from an opaque, light-absorbing and/or a reflective material. In example 15, the subject matter of any one or more of examples 12 to 14 may include, wherein each optical pathway of the SOCD is shaped as a cylindrical tunnel, a tapered tunnel, or a tapered slit, and forms a hole inside the base structure, such as to enable light incoming from one side of the SOCD be directed such that it exits another side of the SOCD. In example 16, the subject matter of any one or more of examples 12 to 14 may include, wherein each optical pathway of the SOCD is an optical waveguide. In example 17, the subject matter of any one or more of examples 12 to 16 may include, wherein the optical system further comprises at least one segmented detector having multiple segments, wherein an output side of each optical pathway is associated with a different segment of the segmented detector, for separate measuring of light exiting from each optical pathway. In example 18, the subject matter of example 17 may include, wherein the segmented detector comprises: an optical sensor array or a pixelated optical detector, wherein each sensor in the sensors array or each pixel of the pixelated detector is coupled to or located in proximity to a different output side of a specific optical pathway, from which light exits. In example 19, the subject matter of any one or more of examples 12 to 18 may include, wherein the SOCD is located in a specific position in respect to the optical element, the optical element being located and configured to spectrally refract or diffract light passing therethrough such that each wavelength (WL) or WL band of an incoming light is directed by the optical element to a different propagation trajectory, wherein the location over the base structure and the characteristics of each optical pathway is designed for optimal collection of light of a specific WL or WL band, based on estimated or measured intensity of the respective WL or WL band and based on the WL/WL band propagation direction when exiting the optical element. In example 20, the subject matter of example 19 may include, wherein the optical element is a diffraction grating optical element or an optical prism. In example 21, the subject matter of any one or more of examples 19 to 20 may include, wherein the light illuminating the optical element emanates from a water sample being illuminated by at least one light source, for optical measurements of the water sample. In example 22, the subject matter of any one or more of examples 12 to 21 may include, wherein the density of optical pathways per area or segment of the SOCD varies between different areas/segments. In example 23, the subject matter of example 22 may include, wherein each segment or area of the SCOD is associated with a corresponding pixel or area of the optical detector.

Claims

CLAIMS 1. A selective optical collection device (SOCD) comprising: • a base structure; and • multiple optical pathways located over the base structure, wherein at least one of the optical pathways of the SOCD is different in one or more of its characteristics in respect to characteristics of at least one other optical pathway of the SOCD, the optical pathway characteristics being associated at least with geometrical dimensions of each optical pathway, inclination angle of each optical pathway, and/or one or more optical properties, wherein differences in characteristics of at least some of the optical pathways, are designed for selective spatial collection of incoming light, by allowing collecting more light passed through one or more of the optical pathways in respect to light passed through one or more other optical pathways.

2. The SOCD of claim 1, wherein the one or more characteristics of the optical pathways further comprise at least one of: dimensions, size, shape, tilt angle relative to the optical axis, optical characteristics, input and/or output aperture shape and/or size.

3. The SOCD of any one or more of claims 1 to 2, wherein the base structure is made from an opaque, light-absorbing, reflective, semi-reflective and/or semi-transparent material.

4. The SOCD of any one or more of claims 1 to 3, wherein each optical pathway is shaped as a cylindrical tunnel, a tapered tunnel, a tapered slit, and forms a hole inside the base structure, such as to enable light incoming from one side of the optical enhancement device to be directed such that it exits another side of the optical enhancement device.

5. The SOCD of any one or more of claims 1 to 3, wherein each optical pathway is an optical waveguide, such as to enable light incoming from one side of the optical enhancement device be directed such that it is directed to exit another side of the optical enhancement device.

6. The SOCD of any one or more of claims 1 to 5, wherein the SOCD is positioned in relation to a segmented detector such that each segment of the segmented detector is configured and positioned to detect optical characteristics of light exiting from a different area or optical pathway of the SOCD.

7. The SOCD of claim 6, wherein the segmented detector comprises: an array of optical sensors or a pixelated optical detector, wherein each sensor in the sensors array or each pixel of the pixelated detector is coupled or located in proximity to a different output side of a specific optical pathway, from which light exits.

8. The SOCD of any one or more of claims 1 to 7 being located in a specific position in respect to an optical element, the optical element being located and configured to spectrally refract or diffract light passing therethrough such as to form multiple monochromatic output beams exiting the optical element, wherein optical pathways of the SOCD are located and configured for optimal collection of a specific monochromatic beam emanating from the optical element, based on expected intensity, directionality and/or WL of the respective monochromatic beam.

9. The SOCD of claim 8, wherein the optical element is a diffraction grating optical element or an optical prism.

10. The SOCD of any one of claims 8 to 9, wherein the light illuminating the optical element emanates from a water sample being illuminated by at least one light source, for optical measurements of the water sample.

11. The SOCD of any one or more of claims 1 to 10, wherein the density of optical pathways per area or segment of the SOCD varies between different areas/segments.

12. An optical system comprising at least: • an optical element configured for spectral diffraction and/or refraction of light; and • a selective optical collection device (SOCD) comprising: (iii) a base structure; and (iv) multiple optical pathways deployed over the base structure at different locations, wherein at least one of the optical pathways has one or more different characteristics in respect to geometrical characteristics of at least one other optical pathway of the SOCD, the characteristics comprising at least inclination angle of the respective optical path, in relation to a main axis, wherein the differences in characteristics of at least some of multiple optical pathways, are designed for selective spatial collection of incoming light.

13. The optical system of claim 12, wherein the one or more characteristics of the optical pathways of the SOCD further comprise at least one of: dimensions, size, optical characteristics, input and output aperture sizes.

14. The optical system of any one or more of claims 12 to 13, wherein the base structure of the SOCD is made from an opaque, light-absorbing and/or a reflective material.

15. The optical system of any one or more of claims 12 to 14, wherein each optical pathway of the SOCD is shaped as a cylindrical tunnel, a tapered tunnel, or a tapered slit, and forms a hole inside the base structure, such as to enable light incoming from one side of the SOCD be directed such that it exits another side of the SOCD.

16. The optical system of any one or more of claims 12 to 14, wherein each optical pathway of the SOCD is an optical waveguide.

17. The optical system of any one or more of claims 12 to 16 further comprising at least one segmented detector having multiple segments, wherein an output side of each optical pathway is associated with a different segment of the segmented detector, for separate measuring of light exiting from each optical pathway.

18. The optical system of claim 17, wherein the segmented detector comprises: an optical sensor array or a pixelated optical detector, wherein each sensor in the sensors array or each pixel of the pixelated detector is coupled to or located in proximity to a different output side of a specific optical pathway, from which light exits.

19. The optical system of any one or more of claims 12 to 18 , wherein the SOCD is located in a specific position in respect to the optical element, the optical element being located and configured to spectrally refract or diffract light passing therethrough such that each wavelength (WL) or WL band of an incoming light is directed by the optical element to a different propagation trajectory, wherein the location over the base structure and the characteristics of each optical pathway is designed for optimal collection of light of a specific WL or WL band, based on estimated or measured intensity of the respective WL or WL band and based on the WL/WL band propagation direction when exiting the optical element.

20. The optical system of claim 19, wherein the optical element is a diffraction grating optical element or an optical prism.

21. The optical system of any one of claims 19 to 20, wherein the light illuminating the optical element emanates from a water sample being illuminated by at least one light source, for optical measurements of the water sample.

22. The optical system of any one or more of claims 12 to 21, wherein the density of optical pathways per area or segment of the SOCD varies between different areas/segments.

23. The optical system of claim 22, wherein each segment or area of the SCOD is associated with a corresponding pixel or area of the optical detector.