CN111045218A

CN111045218A - Photosensitive element

Info

Publication number: CN111045218A
Application number: CN201911425739.6A
Authority: CN
Inventors: 陶俊; 朱雪洲; 向少卿
Original assignee: Hesai Photonics Technology Co Ltd
Current assignee: Hesai Photonics Technology Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-21
Anticipated expiration: 2039-12-31
Also published as: CN111045218B

Abstract

The present disclosure provides a photosensitive element, including a planar glass, the planar glass having a first surface and a second surface which are oppositely disposed, the first surface of the planar glass being provided with a light entrance window; the first reflecting film is arranged on the first surface of the plane glass and is configured to carry out total reflection on the light beams from the interior of the plane glass to the direction of the first surface of the plane glass; the second reflecting film is arranged on the second surface of the plane glass and is configured to partially reflect the light beams from the interior of the plane glass to the direction of the second surface of the plane glass; at least two photosensitive units arranged on the second surface and configured to receive at least two transmitted light beams transmitted from the interior of the plane glass to the second surface; the at least two photosensitive units correspond to the at least two transmitted light beams one to one. Thus, a new photosensitive element is provided.

Description

Photosensitive element

Technical Field

The present disclosure relates to sensor technologies, and in particular, to a photosensitive element.

Background

This section provides background information related to the present disclosure, which does not necessarily constitute prior art.

At present, single Photon detection technology is widely used in the fields of laser radar, nuclear physics and the like, and the adopted single Photon devices include PMT (photonic tubes), SPAD (Single Photon Avalanche diode), SPADs (SPAD array) and silicon photonic tubes. In the application field of laser radar, besides detecting whether photons exist, the number of photons reaching the photosensitive surface (i.e. light intensity) also needs to be obtained. Single photon devices, such as SPADs (SPAD arrays) and sipm (silicon photonic laser), which can satisfy the requirement of obtaining the number of photons and are suitable for small-sized laser radars. SPADs form an array by a large number of SPAD units, and the number of received photons is judged by measuring the number of the SPAD units which are excited by photons in the SPADs to avalanche. The structure of SiPM is basically consistent with that of SPADs, and the output signals of the SiPM are output after the signals of all SPAD units are superposed together.

In the prior art, under ideal simplified conditions, the dynamic response range of SiPM/SPADs and the number of photosensitive units are in linear proportion. In order to increase the dynamic response range of SiPM/SPADs, the number of light sensing units needs to be increased to hundreds of thousands. Thus, the following disadvantages may be caused in the photosensitive element in the prior art: the size is large, the cost is high, and the power consumption is large.

Disclosure of Invention

The present disclosure provides a light sensing element and a lidar including the same, which may solve one or more of the technical problems mentioned above.

In a first aspect, the present disclosure provides a photosensitive element, comprising: the plane glass is provided with a first surface and a second surface which are oppositely arranged, the first surface of the plane glass is provided with a light inlet window, and the light inlet window is configured to enable incident light beams to be transmitted into the plane glass; a first reflective film provided on a first surface of the flat glass and configured to totally reflect a light flux directed from inside the flat glass toward the first surface of the flat glass; a second reflective film provided on a second surface of the flat glass, the second reflective film being configured to partially reflect a light flux directed from inside the flat glass toward the second surface of the flat glass; at least two light sensing units arranged on the second surface of the plane glass and configured to receive light beams transmitted to the second surface from the plane glass; the incident light beams are incident into the plane glass from the light incident window, and are reflected by the first reflecting film and the second reflecting film, so that at least two transmitted light beams are obtained on the second surface of the plane glass, and the at least two photosensitive units correspond to the at least two transmitted light beams one to one.

In some embodiments, the at least two light sensing units are coplanar, and an included angle between a plane where the at least two light sensing units are located and the plane glass is an acute angle.

In some embodiments, the angle between the plane of the at least two light sensing units and the plane glass is the same as the incident angle of the incident light beam, wherein the incident angle is the angle between the incident light beam and the normal of the first surface of the plane glass.

In some embodiments, the light sensing element includes at least two detection channels, each of the detection channels includes at least two light sensing units, and the light sensing units belonging to the same detection channel receive light from the same incident light beam.

In some embodiments, the first reflective film is a first type film configured to cover an area of the first surface other than the light entrance window, and the incident light beam cannot be transmitted from the first type film into the planar glass.

In some embodiments, the first reflective film is a second type film covering the first surface, the second type film is configured to allow the incident light beam to transmit into the planar glass, and a stop is disposed on the second type film, wherein a light passing hole of the stop coincides with a position of the light entrance window.

In some embodiments, the distance between the center points of adjacent photosensitive cells, the thickness of the plane glass, and the incident angle of the incident light beam are related as follows:

d＝2h*tanθ₂*cosθ₁

wherein: d is in adjacent photosensitive unitThe distance between the points, h is the thickness of the flat glass, x is the multiplication number, theta₁Angle of incidence, θ₂Is the incident angle of incident light beam is theta₁The angle of refraction in the plane glass.

In some embodiments, the photosensitive element further includes a band-pass filter, wherein the band-pass filter is disposed between the planar glass and the photosensitive unit.

In some embodiments, a partition wall is disposed between adjacent photosensitive cells, the partition wall has a light transmittance smaller than a preset light transmittance threshold, and the partition wall is used for preventing optical crosstalk between the photosensitive cells.

In some embodiments, the height of the partition wall is determined according to the distance between the plane glass and the plane where the photosensitive unit is located, and the partition wall set can support the plane glass.

In a second aspect, the present disclosure provides a lidar comprising a light-sensing element as in any one of the first aspects.

Therefore, according to the photosensitive element provided by the embodiment of the disclosure, the light intensity distributed by the photosensitive units in at least two photosensitive units can be attenuated exponentially and gradually by using the light energy space distribution mode. Therefore, a larger dynamic response range can be realized by adopting a smaller number of photosensitive units, so that the surface size of the photosensitive element can be reduced, the working energy consumption of the photosensitive element can be reduced, and the manufacturing cost of the photosensitive element can be reduced.

Drawings

The foregoing and additional features and characteristics of the present disclosure will be better understood from the following detailed description, taken with reference to the accompanying drawings, which are given by way of example only and which are not necessarily drawn to scale. Like reference numerals are used to indicate like parts in the accompanying drawings, in which:

FIG. 1 is a schematic side view of a photosensitive element according to an embodiment of the disclosure;

FIG. 2 is a schematic side view of another photosensitive element according to an embodiment of the disclosure;

FIG. 3 is a schematic structural diagram of a photosensitive element according to an embodiment of the disclosure;

FIG. 4 is a schematic view of another structure of a photosensitive element according to an embodiment of the disclosure;

FIG. 5 is a schematic view of another structure of a photosensitive element according to an embodiment of the disclosure;

FIG. 6 is a schematic side view of yet another photosensitive element according to an embodiment of the present disclosure; wherein:

1-plane glass, 11-first surface, 12-second surface; 2-a first reflective film; 3-a second reflective film; 4-a photosensitive unit; 5-a target plane; 6-partition wall.

Detailed Description

Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

In the description of the present disclosure, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present disclosure and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present disclosure. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are capable of operation in sequences other than those illustrated or otherwise described herein.

As shown in fig. 1, an embodiment of the present disclosure provides a photosensitive element, and fig. 1 is a schematic side view of the photosensitive element. The photosensitive element may include a plane glass 1, a first reflective film 2, a second reflective film 3, and a photosensitive unit 4. The number of the photosensitive units may be at least two.

In this embodiment, the above-mentioned flat glass may have a first surface 11 and a second surface 12 which are oppositely disposed.

Here, a light entrance window is disposed on the first surface 11 of the flat glass, and the light entrance window is configured to transmit an incident light beam into the flat glass 1. Here, the planar glass may be a general name for a medium of a planar structure, and the glass should not be construed as a limitation to a material of the medium.

Here, the light entrance window is provided, which may mean that an incident light beam can enter the planar glass from a certain area of the first surface (i.e., the light entrance window), which may be the same as or different from other areas of the first surface; in other words, from the aspect of physical appearance, the light entrance window may or may not be clearly distinguished from other areas of the first surface; without significant distinction, the light entrance window may be formed by limiting the incident position of the incident light beam.

In this embodiment, the first reflective film 2 may be disposed on the first surface 11 of the flat glass 1, and may be configured to totally reflect a light beam from inside the flat glass toward the first surface of the flat glass. In other words, the first reflective film may totally reflect the first light beam; the first beam of light may be within the planar glass and directed towards the first surface of the planar glass.

Referring to fig. 1, the first reflective film 2 is attached to the first surface 11, it can be understood that the thickness of the first reflective film in fig. 1 is relatively large in order to clearly show the first reflective film; in practical applications, the thickness of the first reflective film can be set according to practical situations, and fig. 1 should not be interpreted as a limitation to the thickness of the first reflective film. In fig. 1, the light beam within the plane glass that is directed to the first surface 11 (or the first reflective film 2) may be referred to as the first light beam. The first reflection film 2 may perform total reflection on the first light beam.

Here, the first reflective film functions to totally reflect the first light beam. It is to be understood that the specific structure or specific material of the first reflective film that can realize the above total reflection function may be various, and is not limited herein.

In the present embodiment, the second reflective film 3 is disposed on the second surface 12 of the planar glass 1 and configured to partially reflect the light beam from the inside of the planar glass toward the second surface of the planar glass. In other words, the second reflective film may partially reflect the second light beam; the second beam may be within the planar glass and directed toward the second surface of the planar glass.

In FIG. 1, a second reflective film may be attached to the second surface 12, it being understood that the thickness of the second reflective film in FIG. 1 is relatively large in order to clearly illustrate the second reflective film; in practical applications, the thickness of the second reflective film may be set according to practical situations, and fig. 1 should not be interpreted as a limitation on the thickness of the second reflective film. In fig. 1, the light beam within the plane glass 1, which is directed to the second surface 12 (or the second reflective film 3), may be referred to as the second light beam. The second reflective film 3 may partially reflect the second light beam.

Here, the second reflective film functions to partially reflect and partially transmit the second light beam. It is to be understood that the specific structure or specific material of the second reflective film capable of realizing the above-mentioned partially reflective and partially transmissive function can be various, and is not limited herein.

In this embodiment, the at least two light sensing units 4 are disposed on the second surface of the planar glass 1 and configured to receive the light beams transmitted from the inside of the planar glass to the second surface.

It will be appreciated that the second reflective film 3 is partially reflective, as well as partially transmissive, to the second light beam. The reflected light of the second reflection film 3 is referred to as the above-described first light flux. The transmitted light of the second reflective film 3 may be referred to as a third light beam, in other words, the third light beam may refer to a light beam transmitted to the second surface within the planar glass.

In this embodiment, the incident light beam may be incident into the planar glass from the light incident window, and reflected by the first reflective film and the second reflective film, so as to obtain at least two transmitted light beams on the second surface of the planar glass, where the at least two light sensing units correspond to the at least two transmitted light beams one to one. Here, each light-sensing unit may receive a transmitted light beam, where the light-sensing unit is, for example, a SPAD (single photon avalanche diode, operating in geiger mode).

As an example, the second reflective film may have a light transmittance of T and a reflectance R of 1-T; since the flat glass and the second reflective film are thin, the light absorption by the flat glass and the second reflective film is negligible. When an incident light beam (the light intensity is set to be 1) passes through the plane glass to reach the second surface 12, the incident light beam is influenced by the second reflecting film 3 arranged on the second surface 12, part of light of R is reflected to the plane glass, and the rest part of light of T passes through the second surface 12 and the second reflecting film 3 to reach the photosensitive unit; the light of the R portion reflected on the second surface reaches the first surface 11 and is then totally reflected by the first reflective film 2 provided on the first surface 11.

In the above example, the light of the R portion totally reflected by the first reflective film 2, similarly to the process of the above example, the R portion is reflected by the second reflective film, and the T portion is transmitted by the second reflective film. However, the light intensity reaching the second surface for the second time is R, the light intensity transmitting the second reflection film for the second time is T R, and the light intensity reflecting the second reflection film to the plane glass for the second time is R²。

In the same way as the above example, the light intensity of the third light transmitted through the second reflective film is T R². The light intensity of the fourth transmission through the second reflection film is T R³. The light intensity of the nth time of light passing through the second reflecting film is T R^(n-1)Here, n is 1 or more.

As an example, assuming that the transmittance of the second reflective film is R, the probability of a photon being detected is p, and the light intensity I of the incident light beam is₀Can be calculated by the following process: if all the photosensitive cells less than or equal to n receive light to excite the geiger avalanche (n is 1,2,3 …), and none of the photosensitive cells more than n is excited, it means that the number of photons received by the nth photosensitive cell just reaches its trigger geiger avalanche, and the number of photons received by the (n + 1) th photosensitive cell does not satisfy its trigger geiger avalanche, and the following inequalities (1) and (2) hold.

I₀R^n-1(1-R) p is more than or equal to 1- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

I₀Rⁿ*(1-R)*p<1- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The above inequalities are arranged, and the range of the light intensity of the obtained incident light beam is shown as inequality (3).

1/(Rⁿ*(1-R)*p)>I₀≥1/(R^n-1(1-R) p-o-inequality (3)

In inequalities (1), (2) and (3), "/" indicates division and "+" indicates multiplication.

It can be seen that, through the photosensitive element that this disclosure provided, can utilize the mode of light energy space distribution, in two at least photosensitive units, the light intensity that photosensitive unit distributed attenuates step by step according to the exponent. Therefore, a larger dynamic response range can be realized by adopting a smaller number of photosensitive units.

To further clearly illustrate the technical effects of the photosensitive elements provided by the present disclosure, please refer to table 1, which shows the light intensities received by the respective photosensitive units. Assuming that the light intensity of an incident light beam is a relative light intensity of 1, the light transmittance of the second reflective film may be T equal to 0.1, the reflectance R equal to 0.9, the photosensitive cells are referred to as pixels (pixels), and each pixel is numbered.

Pixel point

pixel1

pixel2

pixel3

pixel4

pixel5

pixel6

pixel7

pixel8

Calculation process

0.1

0.9*0.1

0.9²*0.1

0.9³*0.1

0.9⁴*0.1

0.9⁵*0.1

0.9⁶*0.1

0.9⁷*0.1

Light intensity

0.1

0.09

0.081

0.0729

0.06561

0.05905

0.05314

0.04783

Pixel point

Pixel9

Pixel10

Pixel11

Pixel12

Pixel13

Pixel14

…

Pixel67

Calculation process

0.9⁸*0.1

0.9⁹*0.1

0.9¹⁰*0.1

0.9¹¹*0.1

0.9¹²*0.1

0.9¹³*0.1

…

0.9⁶⁶*0.1

Light intensity

0.04305

0.03874

0.03487

0.03138

0.02824

0.02542

…

9.55E-5

TABLE 1

As can be seen from Table 1, the relative intensity received by pixel1 is 0.1, the relative intensity received by pixel67 is 9.55E-5 times, the relative intensity received by pixel1 is 1047 times that received by pixel67, and the dynamic response range of 1000 times can be realized by 67 pixels.

In contrast, in prior art SiPM/SPADs, under ideal simplified conditions, the dynamic response range of SiPM/SPADs and the number of photosensitive units are in linear proportion. It is considered that if the dynamic response range needs to be expanded by 100 times, the number of the photosensitive units needs to be expanded by one hundred times. In order to improve the dynamic response range of SiPM/SPADs, the photosensitive unit is required to be arrangedThe number is increased to hundreds of thousands. Thus, the following disadvantages may be caused in the photosensitive element in the prior art: firstly, since the size of the photosensitive unit (for example, SPAD) cannot be made too small, the fill factor of SPAD is too low (the fill factor can be understood as the ratio of the size of the photosensitive surface to the size of the whole photosensitive unit), and the effective photon detection probability is reduced, generally, the side length of the photosensitive unit of SiPM/SPADs is about tens of um, so that the area of the detection unit increases linearly as the number of the units increases. The area of a single-channel detector of 10000 photosensitive units is 4mm by estimating the photosensitive units with the side length of 20um². Secondly, the probability index of the photosensitive unit failure in the array is increased while the number of the photosensitive units is increased, so that the production cost is more expensive. Third, the increase in the number of light-sensing units further leads to a linear increase in device power consumption.

Therefore, the photosensitive element provided by the embodiment of the disclosure can realize response in a large dynamic range by adopting a small number of photosensitive units, so that the size of the photosensitive element can be reduced, the working energy consumption of the photosensitive element can be reduced, and the manufacturing cost of the photosensitive element can be reduced.

In some embodiments, the at least two photosensitive units may or may not be coplanar.

It is understood that when we say that the light sensing units are coplanar, the light sensing units are not regarded as points, but rather as solids having light sensing surfaces, and the coplanar light sensing units can be the coplanar light sensing surfaces of the two light sensing units.

Referring to fig. 2, the target plane 5 is shown in fig. 2. The target plane 5 may indicate a plane where the at least two light sensing units are located, for example, a plane where the whole of the at least two light sensing units and the circuit connection structure thereof is located.

Here, the angle between the target plane 5 and the plane glass is an acute angle.

It should be noted that, the photosensitive units of the photosensitive element are coplanar, so that the photosensitive element has a simple structure, is convenient to manufacture and is simple and convenient to install.

In this embodiment, an angle between a plane where the at least two light sensing units are located and the plane glass is the same as an incident angle of the incident light beam, where the incident angle is an angle between the incident light beam and a normal of the first surface of the plane glass. Referring to FIG. 2, the angle between the target plane 5 and the plane glass, which is the same as the incident angle of the incident light beam, is θ₁. Therefore, the light beam emitted from the plane glass can be ensured to be vertical to the target plane, and the light detection efficiency of the photosensitive unit can be improved.

In some embodiments, the light sensing element may include at least two detection channels, each of the detection channels includes at least two light sensing units, and the light sensing units belonging to the same detection channel receive light from the same incident light beam, or the light sensing units in each of the detection channels receive light from the same incident light beam. The light received by the light sensing units in different detection channels comes from different incident light beams. In other words, if the light received by at least two light-sensing units is from the same incident light beam, the at least two light-sensing units can be used as a detection channel. Here, the arrangement form of the photosensitive units in the same detection channel is not limited; the light sensing units in the same detection channel may or may not be coplanar.

In some embodiments, the light sensing element may comprise one or at least two detection channels. If the photosensitive element includes at least two detection channels, the arrangement of the detection channels in the photosensitive element is not limited, and the at least two detection channels may be coplanar or non-coplanar.

As an example, at least two of the light sensing units in the detection channel may form a line array. At least two detection channels in the light-sensing element may form an area array.

Referring to fig. 3, a hatched area shown on the first surface of the flat glass 1 in fig. 3 may represent the first reflective film 2. In FIG. 3, the photosensitive cells of 4 rows and 4 columns are shown. Each row of light-sensing units may serve as a detection channel.

In some embodiments, the arrangement of the light entrance window is optional.

In some embodiments, please refer to fig. 3, which illustrates an exemplary structure of the light entrance window, where the first surface uncovered by the first reflective film may be understood as the light entrance window, that is, the light entrance window may be configured as an elongated shape, and the incident light beams enter from different positions of the elongated shape and may correspondingly enter different detection channels. In this case, the light entrance window may be a preset concept.

In some embodiments, please refer to fig. 4, which illustrates an exemplary structure of the light entrance window, that is, the light entrance window may be configured as a single channel window corresponding to a single detection channel, the single channel window may be a physical window, and a physical light shielding device is disposed between each window for isolation.

In some embodiments, the first reflective film is a first type film, the first type film is configured to cover an area of the first surface outside the light entrance window, and the incident light beam cannot be transmitted from the first type film into the planar glass. Referring to fig. 3, a first type of film is shown, i.e. the first reflective film does not cover the light-incident window area.

Here, the first type film functions to block the passage of external light, and totally reflects light within the planar glass toward the first type film. It is understood that the structure and materials of the first type of membrane that can perform the above functions can be various and are not limited thereto. As an example, the first type of film may be a metal film.

In some embodiments, the first reflective film is a second type of film covering the first surface. The second type of film is configured to allow transmission of the incident light beam into the planar glass. The diaphragm is arranged on the second type film. Here, the light passing hole of the diaphragm coincides with the position of the light entrance window.

Here, please refer to fig. 5, which shows a configuration of the second type film. In fig. 5, the first reflective film covers the light entrance window region of the first surface.

Here, the second type film functions to transmit external light into the planar glass and to totally reflect light directed to the second type film within the planar glass. It is understood that the structure and material of the second type of membrane that can perform the above-described functions can be various and are not limited thereto. As an example, the second type of film may be a dielectric film.

Here, although the second type film may allow external light to pass therethrough, it may be ensured that the external light passes through the light entrance window region in various ways. For example, it is possible to control the incident position of the incident light beam to ensure that the incident light beam only enters from the light entrance window. For example, a light stop may be added to the second type of film to ensure that the non-light-incident window area of the first surface is not clear.

In some embodiments, the position and shape of the diaphragm can be flexibly set according to the arrangement mode of the light entrance window.

In some embodiments, the distance between the center points of adjacent photosensitive cells, the thickness of the plane glass, and the incident angle of the incident light beam can be related as shown in formula (1):

d＝2h*tanθ₂*cosθ₁formula (1)

Here, referring to fig. 2, d may be a distance between center points of adjacent photosensitive cells, h may be a thickness of the plane glass, x may be a multiplication sign, and θ may be₁May be the angle of incidence, θ, of the incident beam₂May be such that the incident angle of the incident beam is θ₁The angle of refraction in the plane glass.

It will be appreciated that at θ₁And refractive index of plane glass, theta₂The angle value of (a) is determined. For the sake of simplicity of the formula, θ is introduced here₂(ii) a In fact, θ₂May also pass through theta₁And refractive index of the flat glass. The above d may be equivalently replaced by the distance between the same positions of the adjacent light sensing units, for example, if the light sensing units are square, the distance between the same positions of the adjacent light sensing units.

The parameter values of the parameters in the above formula (1) may be set according to actual conditions, and are not limited herein. In addition, the sequence of each parameter value is determined, and is not limited herein; as an example, d and θ may be determined first₁Then h is determined; h and theta may also be determined first₁Then d is determined; it is also possible to determine d and h first and then θ 1.

In some embodiments, the light transmittance of the second reflective film may be set according to the light intensity of an incident light beam.

For example, if the incident light intensity is weak, the transmittance of the second reflective film can be improved a little, for example, if the reflectance of the second reflective film is 0.5, please refer to table 1, then pixel1 receives a relative light intensity of 0.5, and pixel11 receives a relative light intensity of 0.5¹⁰0.5-4.88E-4, the light intensity received by pixel1 is 1024 times the light intensity received by pixel11, and 11 pixels can achieve 1024 times of dynamic response range.

Therefore, the light transmittance of the second reflecting film is determined according to the light intensity of the incident light beam, the dynamic response range can be ensured, and the number of the photosensitive units is reduced, so that the dynamic response range of the photosensitive element and the number of the photosensitive units can be balanced, namely, the performance of the photosensitive element is ensured, and the cost of the photosensitive element is reduced.

In some embodiments, the light sensing element further comprises a band pass filter (not shown in the figures). Here, the band pass filter is provided between the flat glass and the photosensitive unit.

Here, the arrangement position of the band pass filter is not limited. For example, the band pass filter may be provided on the second reflective film, or the band pass filter may be provided on each of the light sensing units.

It should be noted that, the band-pass filter can screen light entering the photosensitive unit according to needs, so as to reduce interference of stray light in the environment on the photosensitive element.

In some embodiments, a partition wall is disposed between the adjacent photosensitive cells, and a light transmittance of the partition wall is less than a predetermined light transmittance threshold. The partition wall is used for preventing optical crosstalk between the photosensitive cells.

In some embodiments, referring to fig. 6, a partition wall 6 may be disposed between adjacent photosensitive cells of the same detection channel. Between two light sensing units of different detection channels, if the two light sensing units are adjacent, a partition wall may also be provided between the two light sensing units.

Here, the preset transmittance threshold may be flexibly set according to an actual application scenario, and is not limited herein.

Here, the above optical crosstalk may include, but is not limited to, at least one of: the light beams interfere, and the light beams are not detected by the corresponding photosensitive units but detected by the adjacent photosensitive units.

It should be noted that, for the photosensitive unit, the partition wall disposed around the photosensitive unit may form a partition cavity surrounding the photosensitive unit.

Referring to fig. 6, the included angle between the target plane 5 and the plane glass is an acute angle, which results in different distances from the photosensitive units to the plane glass. Thereby, the height of the partition wall around different photosensitive cells can be different. Furthermore, the partition wall portion or the whole of the object plane 5 may serve as a load-bearing structure for supporting the flat glass.

The present embodiments provide a lidar that may include any of the light-sensing elements provided in the present disclosure.

As an example, the light sensing element in the laser radar can be used as a photodetector of the laser radar and is installed at the receiving end of the laser radar. The target plane 5 of the light-sensitive element may be arranged at the focal plane of the lidar receiving lens system for converting the optical signal converged by the receiving lens system onto the light-sensitive element into an electrical signal. The electrical signal converted by the photosensitive element can be processed by a processing unit of the laser radar to obtain environmental information of the environment where the laser radar is located, such as distance, reflectivity and the like.

It is obvious that further different embodiments can be devised by combining different embodiments and individual features in different ways or modifying them.

The scanning device and the lidar including the same and the operating method according to the preferred embodiments of the present disclosure have been described above with reference to specific embodiments. It is understood that the above description is intended to be illustrative, and not restrictive, and that various changes and modifications may be suggested to one skilled in the art in view of the foregoing description without departing from the scope of the disclosure. Such variations and modifications are also intended to be included within the scope of the present disclosure.

The above embodiments are only used for illustrating the technical solutions of the present disclosure, and not for limiting the same; although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present disclosure.

Claims

1. A photosensitive element, comprising:

the plane glass is provided with a first surface and a second surface which are oppositely arranged, a light inlet window is arranged on the first surface of the plane glass, and the light inlet window is configured to enable incident light beams to be transmitted into the plane glass;

the first reflecting film is arranged on the first surface of the plane glass and is configured to carry out total reflection on the light beams from the interior of the plane glass to the direction of the first surface of the plane glass;

the second reflecting film is arranged on the second surface of the plane glass and is configured to partially reflect the light beams from the interior of the plane glass towards the direction of the second surface of the plane glass;

at least two light sensing units arranged on the second surface of the plane glass and configured to receive light beams transmitted to the second surface from the plane glass;

incident beams are incident into the plane glass from the light incident window and are reflected by the first reflecting film and the second reflecting film, at least two transmitted beams are obtained on the second surface of the plane glass, and the at least two photosensitive units correspond to the at least two transmitted beams one to one.

2. A photosensitive element according to claim 1, wherein said at least two photosensitive units are coplanar, and an included angle between a plane of said at least two photosensitive units and said plane glass is an acute angle.

3. The photosensitive element according to claim 2, wherein the plane of the at least two photosensitive units is at the same angle with the plane glass as the incident angle of the incident light beam, wherein the incident angle is the angle between the incident light beam and the normal of the first surface of the plane glass.

4. A photosensitive element according to claim 1, wherein the photosensitive element comprises at least two detection channels, each detection channel comprises at least two photosensitive units, and the photosensitive units belonging to the same detection channel receive light from the same incident light beam.

5. A photosensitive element according to claim 1, wherein said first reflective film is a first type film configured to cover an area of said first surface other than said light entrance window.

6. The photosensitive element according to claim 1, wherein the first reflective film is a second type film covering the first surface, the second type film being configured to allow the incident light beam to transmit into the planar glass, and a diaphragm is provided on the second type film, wherein a light passing hole of the diaphragm coincides with a position of the light entrance window.

7. The photosensitive element according to claim 3, wherein the distance between the center points of the adjacent photosensitive cells, the thickness of the plane glass, and the incident angle of the incident light beam are related as follows:

d＝2h*tanθ₂*cosθ₁

wherein: d is the distance between the center points of the adjacent photosensitive units, h is the thickness of the plane glass, is the multiplication sign, and theta₁Angle of incidence, θ₂Is the incident angle of incident light beam is theta₁The angle of refraction in the plane glass.

8. A photosensitive element according to claim 1, further comprising a band-pass filter, wherein the band-pass filter is provided between the planar glass and the photosensitive unit.

9. The photosensitive element according to any one of claims 1 to 8, wherein a partition wall is provided between adjacent photosensitive cells, a light transmittance of the partition wall is less than a preset light transmittance threshold, and the partition wall is used for preventing optical crosstalk between the photosensitive cells.

10. A photosensitive element according to claim 9, wherein the height of the partition walls is determined according to the distance between the planar glass and the plane in which the photosensitive unit is located, and the set of partition walls is capable of supporting the planar glass.

11. Lidar characterized in that it comprises a light-sensitive element according to any of claims 1 to 10.