CN217007870U

CN217007870U - Polarization beam splitting module and four-beam polarization beam splitting system thereof

Info

Publication number: CN217007870U
Application number: CN202220931315.8U
Authority: CN
Inventors: 钟润文; 傅旭文
Original assignee: Guangzhou Tyrafos Semiconductor Technologies Co Ltd
Current assignee: Guangzhou Tyrafos Semiconductor Technologies Co Ltd
Priority date: 2022-04-21
Filing date: 2022-04-21
Publication date: 2022-07-19
Anticipated expiration: 2032-04-21

Abstract

The utility model provides a polarization beam splitting module and a four-beam polarization beam splitting system thereof. The polarization beam splitting module includes: linear polarizer, quarter-phase retarder, spectroscope, air layer, reflector and isolating layer. The linear polarizer is used for converting any light beam into linearly polarized light, the quarter-phase retarder is used for converting the linearly polarized light and the circularly polarized light, the spectroscope is used for dividing a beam of circularly polarized light into two left-handed (right-handed) circularly polarized lights which have the same phase and light intensity and the mutually vertical advancing directions, the left-handed (right-handed) circularly polarized lights pass through an air layer and the reflector and then convert the left-handed (right-handed) circularly polarized lights into right-handed (left-handed) circularly polarized lights, the reflector is used for changing the transmission direction of the light beam, and the isolation layer is used for protecting the polarization beam splitting module. The utility model further provides a four-beam polarization splitting system comprising the polarization splitting module.

Description

Polarization beam splitting module and four-beam polarization beam splitting system thereof

Technical Field

The present invention relates to a polarization beam splitting module, and more particularly, to a four-beam polarization beam splitting system that can be easily processed by the polarization beam splitting module.

Background

As ranging technology evolves, various ranging technologies are continuously developed and widely applied to, for example, vehicle distance detection, face recognition, and various Internet of Things (IoT) devices. Common distance measuring techniques are, for example, Infrared (IR) technique, ultrasonic (Ultrasound) technique, and Pulsed Light (IPL) technique. However, as the precision of ranging is required to be higher and higher, the pulse light ranging technology using a Time-of-Flight (ToF) measurement method is one of the main research directions in the field.

The flight time measuring method is an active 3D scanning technology which is frequently applied in recent years, and the main reasons are that the measurable distance range is large, the resolution ratio is high, the software complexity is low, and the method is favorable for market expansion and technology development. The sensing technology of the time-of-flight ranging method is to add another sensing component capable of measuring depth information on the traditional image sensor, wherein the component is used for calculating the depth information by sensing the time change received by light reflection.

In the conventional sensing technology of the time-of-flight ranging method, a non-polarized light is generally used as a light source, and in recent years, a sensing technology adopting a polarized light has been developed, and only two light sources and a plurality of polarizing plates have to be used to generate a light source with two orthogonal polarizations as a transmitting light, because the light source with two orthogonal polarizations is not interfered by ambient light under the receiving of a light sensor, so that clear depth information can be obtained.

However, as the smart phone becomes lighter and thinner, the number of components that can be placed in the internal space of the smart phone is reduced, and therefore how to reduce the internal components of the smart phone and the usage space occupied by the components is one of the problems that research and development staff should solve.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a polarization light splitting module which can realize the function of simultaneously finishing exciting lights with different polarization directions by simple processing and combination, thereby simplifying and miniaturizing a polarization light splitting system, further improving the technical performance and reliability of the polarization light splitting system, and having very important practical significance in the application technical fields of optical testing, optical modulation, optical ranging and the like.

Another objective of the present invention is to provide a four-beam polarization splitting system, which can realize four kinds of excitation lights with different polarization directions by simple processing and combination of polarization splitting modules, and reduce the distance measurement sensing technology that can be executed by at least two light sources to generate multiple polarized light sources to only one light source and automatically adjust the polarization direction of the excitation light to execute the operation of the ToF sensing technology, thereby greatly reducing the cost and increasing the stability of the system.

To achieve the above object, the present invention provides a polarization beam splitting system applied in an environment for receiving a pulse light, the polarization beam splitting module comprising: a linear polarizer for converting the pulsed light into linearly polarized light; a quarter-phase retarder disposed on the linear polarizer; a spectroscope disposed on the quarter-phase retardation plate, the spectroscope having an incident surface, a first light-emitting surface and a second light-emitting surface; an air layer disposed on the quarter-phase retardation plate and coupled to the second light-emitting surface; a reflector, disposed on the quarter-phase retardation plate and coupled to the second light-emitting surface, for reflecting the light beam to change the transmission direction of the light beam and change the rotation direction of the circularly polarized light; and an isolation layer arranged on the spectroscope and the reflector; wherein the pulsed light is converted into linearly polarized light with a preset polarization direction after passing through the linear polarizer, the linearly polarized light with the preset polarization direction is converted into circularly polarized light with a first polarization direction through the quarter-phase retarder, the circularly polarized light with the first polarization direction enters the spectroscope from the incident surface, the spectroscope outputs the circularly polarized light with the first polarization direction transmitted along the first direction to the isolation layer from the first light-emitting surface, and the beam splitter outputs the circularly polarized light with the first polarization direction transmitted along a second direction from the second light-emitting surface, the circularly polarized light with the first polarization direction passes through the air layer to the reflector to be reflected, and the polarization direction is changed to form circularly polarized light with a second polarization direction, the circularly polarized light having the second polarization direction is turned from being transmitted in the second direction to being transmitted in the first direction to the spacer layer.

Preferably, according to the polarization splitting module of the present invention, the linear polarizer is a metal grating.

Preferably, according to the polarization splitting module of the present invention, the first direction is orthogonal to the second direction.

Preferably, according to the polarization beam splitting module of the present invention, the wavelength of the pulsed light is between 780nm and 1400 nm.

In order to achieve the above object, the present invention further provides a four-beam polarization splitting system based on the polarization splitting module, comprising: the first polarization light splitting module is used for receiving the pulse light, the first polarization light splitting module comprises the polarization light splitting module and a first quarter phase retarder, the first quarter phase retarder is arranged on the isolation layer and covers the spectroscope, and the first quarter phase retarder is used for converting the circularly polarized light into linearly polarized light; a second polarization beam splitting module coupled to the first polarization beam splitting module, the second polarization beam splitting module including the polarization beam splitting module and a second quarter-phase retarder disposed on the isolation layer and covering the beam splitter and the reflector, the second quarter-phase retarder being configured to convert circularly polarized light into linearly polarized light; the third polarization beam splitting module is coupled with the first polarization beam splitting module and comprises the polarization beam splitting module; after the second polarization beam splitting module receives the linearly polarized light with the default polarization direction, the second polarization beam splitting module outputs the linearly polarized light with the default polarization direction and the linearly polarized light with the third polarization direction, and after the third polarization beam splitting module receives the circularly polarized light with the second polarization direction, the third polarization beam splitting module outputs the circularly polarized light with the first polarization direction and the polarized light with the fourth polarization direction.

Preferably, in the four-beam polarization splitting system according to the present invention, the default polarization direction and the third polarization direction are mutually orthogonal.

Preferably, in the four-beam polarization splitting system according to the present invention, the third polarization splitting module further includes a polarization layer disposed on the isolation layer, the polarization layer is used for converting circularly polarized light into linearly polarized light.

Preferably, according to the four-beam polarization splitting system of the present invention, the default polarization direction and the fourth polarization direction are different by 45 degrees.

Therefore, the utility model provides a polarization light splitting module, which can realize the function of simultaneously finishing a plurality of exciting lights with different polarization directions by simple processing and combination, thereby simplifying and miniaturizing a polarization light splitting system, further improving the technical performance and reliability of the polarization light splitting module, and having very important practical significance in the application technical fields of optical testing, optical modulation, optical ranging and the like. In addition, the linear polarizer and the quarter-phase retarder of the polarization splitting module can use a double-refraction polarizer, and the double-refraction polarizer has the advantages that the double-refraction polarizer is not easy to change under the irradiation of high-energy laser compared with other polarizers, thereby achieving the effects of preventing heat accumulation after long-time high-energy laser irradiation, and preventing the problems of deformation, deterioration and the like.

To enable those skilled in the art to understand the objects, features and effects of the present invention, the present invention will be described in detail with reference to the following embodiments in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a block diagram of a polarization splitting module according to the present invention;

FIG. 2 is a schematic diagram of a polarization beam splitting module according to the present invention;

FIG. 3 is a schematic diagram illustrating the polarization beam splitting module of the present invention receiving incident light from the external environment;

fig. 4 to 6 are schematic diagrams of various other exemplary polarization splitting modules, respectively;

FIG. 7 is a schematic diagram of an exemplary four-beam polarization splitting system.

Description of reference numerals:

100. 100A, 100B, 100C-polarization beam splitting module;

11. 11A, 11B, 11C-linear polarizers;

12. 12A, 12B, 12C-quarter phase retarders;

121-a first quarter-phase retarder;

122-a second quarter-phase retarder;

13. 13A, 13B, 13C is spectroscope;

131-an incident face;

132-a first light-emitting surface;

133-a second light emitting surface;

14. 14A, 14B, 14C-mirrors;

15. 15A, 15B, 15C-isolation layers;

16-an air layer;

17-a polarizing layer;

a-presetting a polarization direction;

a1 — first polarization direction;

a2 — second polarization direction;

a 3-third polarization direction;

a 4-fourth polarization direction;

l-linearly polarized light;

lc-circularly polarized light;

lcl-left-handed polarized light;

lcr-right-handed polarized light;

PL-pulsed light;

x-a first direction;

y-second direction.

Detailed Description

The inventive concept will now be explained more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the inventive concept are shown. Advantages and features of the inventive concept, and methods of accomplishing the same, will become apparent from the following more detailed description of exemplary embodiments, as illustrated in the accompanying drawings. It should be noted, however, that the inventive concept is not limited to the following exemplary embodiments, but may be embodied in various forms. Accordingly, the exemplary embodiments are provided only to disclose the inventive concept and to enable those skilled in the art to understand the category of the inventive concept. In the drawings, exemplary embodiments of the inventive concept are not limited to the specific examples provided herein and are exaggerated for clarity.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present.

Similarly, it will be understood that when an element (e.g., a layer, region or substrate) is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, the term "directly" means that there are no intervening components present. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Furthermore, exemplary embodiments in the detailed description will be described by way of cross-sectional views of idealized exemplary diagrams that are the concept of the present invention. Accordingly, the shape of the exemplary figures may be modified according to manufacturing techniques and/or allowable errors. Accordingly, exemplary embodiments of the inventive concept are not limited to the specific shapes shown in the exemplary drawings, but may include other shapes that may be produced according to a manufacturing process. The regions illustrated in the figures are of a general nature and are intended to illustrate the particular shape of a component. Therefore, this should not be taken as limiting the scope of the inventive concept.

It should also be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first component in some embodiments may be referred to as a second component in other embodiments without departing from the teachings of the present disclosure. Exemplary embodiments of aspects of the present inventive concept illustrated and described herein include their complementary counterparts. Throughout this specification, the same reference numerals or the same indicators denote the same components.

Further, exemplary embodiments are described herein with reference to cross-sectional and/or plan views, which are idealized exemplary illustrations. Accordingly, departures from the illustrated shapes are contemplated as may result, for example, from manufacturing techniques and/or tolerances. Thus, the exemplary embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of exemplary embodiments.

Referring to fig. 1-3, fig. 1 is a block diagram of a polarization beam splitting module according to the present invention; FIG. 2 is a diagram illustrating details of a polarization beam splitting module according to the present invention; fig. 3 is a schematic diagram illustrating the polarization beam splitting module of the present invention receiving incident light from the external environment. As shown in fig. 1, a polarization beam splitter 100 according to the present invention is applied in an environment receiving pulsed light Lp, and the polarization beam splitter 100 includes: a linear polarizer 11, a quarter-phase retarder 12, a beam splitter 13, a reflecting mirror 14, a spacer 15 and an air layer 16.

Specifically, as shown in fig. 1 and 2, the linearly polarizing plate 11 according to the present invention is configured to convert an arbitrary light beam into linearly polarized light L, wherein the linearly polarizing plate 11 converts incident pulsed light Lp into linearly polarized light L having a preset polarization direction D. Specifically, in some embodiments, the linear polarizer 11 is a metal grating, for example, the linear polarizer 11 may be a half-wave plate in the mhz band fabricated by using a complementary metal grating structure, and metal meshes respectively having a capacitive property and an inductive property are stacked perpendicular to each other, so that electric field components of the incident pulsed light Lp along the two directions undergo different phase changes, thereby changing the polarization state of the pulsed light Lp. Specifically, referring to fig. 3, in some embodiments, the wavelength range of the pulsed light Lp is an infrared wavelength range, and more specifically, the wavelength range of the pulsed light Lp is between 780nm and 1400 nm. And the linearly polarizing plate 11 converts the incident pulsed light Lp into a horizontally linearly polarized light L1, where the preset polarization direction D is a horizontal polarization direction, but the present invention is not limited thereto.

Specifically, as shown in fig. 1 and fig. 2, a quarter-phase retarder 12 according to the present invention is disposed on a linear polarizer 11, and the quarter-phase retarder 12 is used for converting linearly polarized light L into circularly polarized light Lc, wherein the quarter-phase retarder 12 converts linearly polarized light L having a predetermined polarization direction D into circularly polarized light Lc having a first polarization direction D1. Specifically, in some embodiments, quarter-phase retarder 12 may be one of a reflective, dichroic, and birefringent polarizer. Preferably, the quarter-wave retarder 12 may use a birefringent crystal, which has an advantage in that the birefringent crystal is less likely to change under the irradiation of the high-energy laser than other polarizers, thereby achieving the effect of preventing the heat accumulation after the irradiation of the high-energy laser for a long time, causing deformation and deterioration. Therefore, the quarter-wave retarder 12 according to the present invention may use a birefringent crystal to convert the linearly polarized light L into the circularly polarized light Lc. Specifically, as shown in fig. 3, in the present embodiment, the quarter-wave retarder 12 may be a quarter-wave plate (QWP), such that after the horizontally linearly polarized light L1 enters the quarter-wave retarder 12, the quarter-wave retarder 12 converts the horizontally linearly polarized light L1 into the right-handed polarized light Lcr, wherein the first polarization direction D1 is a right-handed polarization direction, but the utility model is not limited thereto.

Specifically, as shown in fig. 1 and fig. 2, the beam splitter 13 according to the present invention is disposed on the quarter-phase retarder 12, the beam splitter 13 has an incident surface 131, a first light emitting surface 132 and a second light emitting surface 133, wherein the circularly polarized light Lc with the first polarization direction D1 enters the beam splitter 13 from the incident surface 131, the beam splitter 13 outputs the circularly polarized light Lc with the first polarization direction D1 transmitted along the first direction X from the first light emitting surface 132 to the separating layer 15, and the beam splitter 13 outputs the circularly polarized light Lc with the first polarization direction D1 transmitted along the second direction Y from the second light emitting surface 133. Specifically, in some embodiments, the beam splitter 13 may be a birefringent polarization device made of natural calcite crystal, and the polarization direction and the beam splitting are changed by using total internal double reflection of incident light on a crystal interface by using a double-reflection structure design, so that the polarization direction, the beam splitting, and the beam steering can be changed and integrated by the beam splitter 13. Specifically, referring to fig. 3, in some embodiments, the right-polarized light Lcr is converted into the right-polarized light Lcr transmitted along the first direction X by the beam splitter 13 to the isolation layer 15, and the right-polarized light Lcr transmitted along the second direction Y is transmitted to the air layer 16, but the utility model is not limited thereto.

Specifically, as shown in fig. 1 and fig. 2, the air layer 16 according to the present invention is disposed on the quarter-wave retarder 12 and coupled to the second light emitting surface 133. Specifically, in some embodiments, the refractive index of the air layer 16 is smaller than the refractive index of the mirror 14, so that the air layer 16 is an optically hydrophobic medium relative to the mirror 14, which causes a change in the polarization direction of the light beam after the light beam is transmitted from the air layer 16 to the mirror 14, resulting in reflected light orthogonal to the original polarization direction of the light beam.

Specifically, as shown in fig. 1 and 2, the reflector 14 according to the present invention is disposed on the quarter-phase retarder 12 and coupled to the second light emitting surface 133, and the reflector 14 is used for reflecting the light beam and further changing the transmission direction of the light beam. Specifically, referring to fig. 2 and fig. 3, in some embodiments, after the right-handed polarized light Lcr transmitted along the second direction Y is transmitted to the reflector 14, a circularly polarized light Lc with a second polarization direction D2 transmitted along the second direction Y is formed, wherein the second polarization direction D2 is a left-handed polarization direction, so that the right-handed polarized light Lcr originally transmitted along the second direction Y is converted into a left-handed polarized light Lcl transmitted along the first direction X and then transmitted to the isolation layer 15. Specifically, in some embodiments, the first polarization direction D1 and the second polarization direction D2 are orthogonal to each other, although the utility model is not limited thereto.

Specifically, as shown in fig. 1 and 2, the isolation layer 15 according to the present invention is disposed on the uppermost layer of the polarization beam splitting module 100. More specifically, the polarization splitting modules 100 are provided between the polarization splitting modules 100 when a plurality of polarization splitting modules 100 are present. Thus, the isolation layer 15 may serve as an isolation structure between the plurality of polarization splitting modules 100 in some embodiments. In the present invention, the word "isolated" is used to cover both electrical and physical isolation. The isolation layer 15 may be a single layer of inorganic encapsulation material, a multi-layer stack of inorganic encapsulation material, or a stack of pairs of inorganic and organic encapsulation materials. The inorganic encapsulation material used is, for example, but not limited to, silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (sion x), aluminum oxide (AlOx), or titanium oxide (TiOx).

It should be noted that the isolation layer 15 of the polarization splitting module 100 according to the present invention can be directly used as a substrate of other polarizers without additional substrates, and a user can directly perform simple processing on the isolation layer 15 to realize excitation lights with different polarization directions, so that the polarization splitting module 100 of the present invention can be thinned, and has wide applicability.

Therefore, the polarization splitting module 100 provided by the utility model can realize the function of simultaneously completing the exciting light of a plurality of different polarization directions by simple processing and combination, so that the polarization splitting system is simplified and thinned, the technical performance and reliability of the polarization splitting system are further improved, and the polarization splitting module has very important practical significance in the application technical fields of optical testing, optical modulation, optical ranging and the like. In addition, the linear polarizer 11 and the quarter-phase retarder 12 of the polarization beam splitting module 100 are less likely to change under the irradiation of the high-energy laser by using the birefringence polarizer, thereby achieving the effects of preventing heat accumulation after the irradiation of the high-energy laser for a long time and preventing deformation and deterioration.

Other examples of polarization splitting modules are provided below to make possible variations that will be apparent to those of ordinary skill in the art to which the present invention pertains. Components designated by the same reference numerals as in the above embodiment are substantially the same as those described above with reference to fig. 1 and 2. The components, features and advantages that are the same as those of the polarization splitting module 100 will not be described again.

Referring to fig. 4, an exemplary first polarization beam splitting module 100A is shown. The difference between the first polarization splitting module 100A and the polarization splitting module 100 is that the first polarization splitting module 100A is further provided with a first quarter-phase retarder 121, the first quarter-phase retarder 121 is disposed on the isolation layer 15A and covers the beam splitter 13A, and the first quarter-phase retarder 121 is used for converting circularly polarized light into linearly polarized light. Specifically, in some embodiments, after the first polarization splitting module 100A receives the pulsed light Lp, the first polarization splitting module 100A outputs linearly polarized light with a default polarization direction D and circularly polarized light with a second polarization direction D2, where the linearly polarized light with the default polarization direction D is the horizontally linearly polarized light L1, and the circularly polarized light with the second polarization direction D2 is the left-handed polarized light Lcl, but the utility model is not limited thereto.

Referring to fig. 5, an exemplary second polarization beam splitting module 100B is shown. The second polarization splitting module 100B is different from the polarization splitting module 100 in that the second polarization splitting module 100B is further provided with a second quarter-phase retarder 122, the second quarter-phase retarder 122 is disposed on the isolation layer 15B and covers the beam splitter 13B and the reflector 14B, and the second quarter-phase retarder 122 is used for converting circularly polarized light into linearly polarized light. Specifically, in some embodiments, after the second polarization splitting module 100B receives the linearly polarized light with the default polarization direction D, the second polarization splitting module 100B outputs the linearly polarized light with the default polarization direction D and the linearly polarized light with the third polarization direction D3, wherein the quarter-phase retarder 12B may be a quarter-wave plate, and the polarization direction D is orthogonal to the third polarization direction D3, so that the linearly polarized light with the polarization direction D is the horizontal linearly polarized light L1, and the linearly polarized light with the third polarization direction D3 is the vertical linearly polarized light L2, which is not limited thereto.

It should be further noted that, compared to the polarization splitting module 100, the beam splitter 13B and the reflection mirror 14B of the second polarization splitting module 100B and the beam splitter 13 and the reflection mirror 14 of the polarization splitting module 100 are mirror-symmetric, and the mirror-symmetric manner can be generated by simply turning the polarization splitting module 100 horizontally by 180 degrees, and then disposing the second quarter-phase retarder 122 on the isolation layer 15B to generate the second polarization splitting module 100B, but the utility model is not limited thereto.

Referring to fig. 6, an exemplary polarization beam splitter module 100C is shown. The third polarization splitting module 100C is different from the polarization splitting module 100 in that the third polarization splitting module 100C is further provided with a polarizing layer 17, the polarizing layer 17 is disposed on the isolation layer 15C and covers the reflector 14C, and the polarizing layer 17 is used for converting circularly polarized light into linearly polarized light. Specifically, in some embodiments, after the third polarization splitting module 100C receives the circularly polarized light with the second polarization direction D2, the third polarization splitting module 100C outputs the circularly polarized light with the first polarization direction D1 and the linearly polarized light with the fourth polarization direction D4, wherein the circularly polarized light with the first polarization direction D1 is the right-handed polarized light Lcr, and the polarizing layer 17 may be a polarizing plate with any polarization direction, in this embodiment, the difference between the fourth polarization direction D4 and the preset polarization direction D is 45 degrees, however, the linearly polarized light with the fourth polarization direction D4 may be linearly polarized light with any polarization angle, which is not limited particularly.

It is to be understood that variations and modifications based on the above examples can be made by those skilled in the art, and are not to be considered as a list. The following will focus on applying the four-beam polarization splitting system according to the embodiment.

Referring to FIG. 7, an exemplary four-beam polarization beam splitting system 10 is shown. As shown in fig. 6, the four-beam polarization splitting system 10 according to the present invention, to which the above-described embodiments are applied, includes: a first polarization beam splitting module 100A, a second polarization beam splitting module 100B, and a third polarization beam splitting module 100C.

For a further understanding of the nature of the structures, operation of the devices, and the intended function of the utility model, reference should be made to the following description of the presently preferred embodiments of the utility model, in which it is believed that the utility model will be more fully understood and described in the following detailed description:

specifically, referring to fig. 7, the actual splitting process of the four-beam polarization splitting system 10 according to the present invention is described as follows: firstly, the first polarization light splitting module 100A receives the pulse light Lp, the first polarization light splitting module 100A outputs horizontal linear polarized light L1 to the second polarization light splitting module 100B, and the first polarization light splitting module 100A outputs left-handed polarized light Lcl to the third polarization light splitting module 100C; then, the second polarization splitting module 100B receives the horizontal linear polarized light L1, and the second polarization splitting module 100B outputs a horizontal linear polarized light L1 with a default polarization direction D and a vertical linear polarized light L2 with a third polarization direction D3; meanwhile, the third polarization beam splitting module 100C receives the left-handed polarized light Lcl, and the third polarization beam splitting module 100C outputs the right-handed polarized light Lcr having the first polarization direction D1 and the linearly polarized light having the fourth polarization direction D4.

Therefore, the present invention can realize the excitation lights with four different polarization directions by simple processing and combination of the polarization beam splitting module 100, and reduces the distance measurement sensing technology which originally needs at least two light sources to generate a plurality of polarized light sources to be executed to the distance measurement sensing technology which needs only one light source and can automatically adjust the polarization direction of the excitation light to execute the operation of the ToF sensing technology, thereby greatly reducing the cost and increasing the stability of the system.

It should be noted that the four-beam polarization splitting system 10 according to the present invention can perform different processing and combination on the polarization splitting module 100, so as to realize four kinds of excitation lights with different polarization directions, and the polarization direction of the polarized light output by the four-beam polarization splitting system 10 can be adjusted according to the user's requirement, for example, when the third polarization splitting module 100C is not provided with the polarizing layer 17, the polarized light output by the four-beam polarization splitting system 10 will be horizontal linearly polarized light L1, vertical linearly polarized light L2, right-handed polarized light Lcr, and left-handed polarized light Lcl. In addition, when the polarization splitting module 100 is subjected to different processes and combinations, the polarization splitting module 100 of the present invention can implement a six-beam polarization splitting system or an eight-beam polarization splitting system, and it can be understood that a person skilled in the art can make various changes and adjustments based on the above examples, which are not listed herein.

Finally, the technical characteristics and the achievable technical effects of the utility model are summarized as follows:

first, the present invention provides a polarization splitting module 100, which can simultaneously complete the function of a plurality of excitation lights with different polarization directions by simple processing and combination, thereby simplifying and thinning a polarization splitting system, further improving the technical performance and reliability thereof, and having very important practical significance in the application technical fields of optical testing, optical modulation, optical ranging, and the like.

Second, the linearly polarizing plate 11 and the quarter-phase retardation plate 12 of the polarization splitting module 100 according to the present invention are less likely to change under the irradiation of high-energy laser by using the birefringence type polarizing plate, so as to achieve the effects of preventing heat accumulation after the irradiation of high-energy laser for a long time, and preventing deformation and deterioration.

Thirdly, the present invention can realize the excitation lights with four different polarization directions by simple processing and combination of the polarization beam splitting module 100, and reduces the distance measurement sensing technology which originally needs at least two light sources to generate a plurality of polarized light sources to be executed to the distance measurement sensing technology which needs only one light source and can automatically adjust the polarization direction of the excitation light to execute the operation of the ToF sensing technology, thereby greatly reducing the cost and increasing the stability of the system.

While the embodiments of the present invention have been described with reference to specific embodiments, those skilled in the art will readily appreciate that other advantages and features of the utility model may be obtained from the disclosure herein.

While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the utility model as defined in the following claims.

Claims

1. A polarization beam splitting module, applied to an environment for receiving a pulse light, comprises:

a linear polarizer for converting the pulsed light into linearly polarized light;

a quarter-phase retarder disposed on the linear polarizer;

a beam splitter, disposed on the quarter-phase retardation plate, having an incident surface, a first light-emitting surface, and a second light-emitting surface;

an air layer disposed on the quarter-phase retardation plate and coupled to the second light-emitting surface;

a reflector, arranged on the quarter-phase retardation plate and coupled to the air layer, for reflecting the light beam, thereby changing the transmission direction of the light beam and changing the rotation direction of the circularly polarized light; and

an isolation layer arranged on the spectroscope and the reflector;

wherein the pulse light is converted into linearly polarized light with a preset polarization direction after passing through the linear polarizer, the linearly polarized light with the preset polarization direction is converted into circularly polarized light with a first polarization direction by the quarter-phase retarder, the circularly polarized light with the first polarization direction enters the spectroscope from the incident plane, the spectroscope outputs the circularly polarized light with the first polarization direction transmitted along the first direction from the first light-emitting plane to the isolation layer, and the beam splitter outputs the circularly polarized light with the first polarization direction transmitted along a second direction from the second light-emitting surface, the circularly polarized light with the first polarization direction passes through the air layer to the reflector to be reflected, and the polarization direction is changed to form circularly polarized light with the second polarization direction, the circularly polarized light having the second polarization direction is turned from being transmitted in the second direction to being transmitted in the first direction to the spacer layer.

2. The polarization beam splitting module of claim 1, wherein the linear polarizer is a metal grating.

3. The polarization beam splitter module of claim 1, wherein the first direction is orthogonal to the second direction.

4. The polarization beam splitter module of claim 1, wherein the pulsed light has a wavelength between 780nm and 1400 nm.

5. A four-beam polarization beam splitting system, comprising:

a first polarization beam splitting module for receiving the pulsed light, the first polarization beam splitting module comprising the polarization beam splitting module according to claim 1 and a first quarter-phase retarder disposed on the isolation layer and covering the beam splitter, the first quarter-phase retarder for converting circularly polarized light into linearly polarized light;

a second polarization splitting module coupled to the first polarization splitting module, the second polarization splitting module comprising the polarization splitting module of claim 1 and a second quarter-wave retarder disposed on the isolation layer and covering the beam splitter and the reflector, the second quarter-wave retarder being configured to convert circularly polarized light into linearly polarized light; and

a third polarization beam splitting module coupled to the first polarization beam splitting module, the third polarization beam splitting module comprising the polarization beam splitting module of claim 1;

wherein, after this pulse light is received to this first polarization beam splitting module, this first polarization beam splitting module exports this linearly polarized light that has acquiescence polarization direction to this second polarization beam splitting module, and this first polarization beam splitting module exports this second polarization direction's circularly polarized light to this third polarization beam splitting module, this second polarization beam splitting module receives this linearly polarized light that has acquiescence polarization direction after, this second polarization beam splitting module exports this linearly polarized light that has acquiescence polarization direction and a linearly polarized light that has third polarization direction, this third polarization beam splitting module receives this second polarization direction's circularly polarized light after, this third polarization beam splitting module exports this circularly polarized light that has first polarization direction and a polarized light that has fourth polarization direction.

6. The four-beam polarization splitting system of claim 5, wherein the default polarization direction and the third polarization direction are orthogonal to each other.

7. The system of claim 5, wherein the third PBS further comprises a polarizer layer disposed on the isolation layer, the polarizer layer converting circularly polarized light into linearly polarized light.

8. The four-beam polarization splitting system of claim 7, wherein the default polarization direction is 45 degrees different from the fourth polarization direction.