An optical path combining chip structure and its application

Abstract

The present invention discloses an optical path combining chip structure and its application, wherein the optical path combining chip structure comprises an optical path combining module, an output light reflecting element and a pair of light sources; wherein the optical path combining module comprises: a polarization beam splitter element having a beam splitting interface; two optical isolation units, each optical isolation unit comprising: a polarizer, a phase delay element, a reflective optical element, and a Faraday rotator arranged along an incident optical path; a third phase delay element and a third reflective optical element arranged along a reflective optical path of the beam splitting interface. The optical path combining chip of the present invention has a wide range of applications, has an optical isolator function, and can be miniaturized, and can meet the requirements of conventional TO-CAN packaging.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to an optical path combining chip structure and its application. Background Art

[0002] Optical combiner devices are used to combine optical signals in different optical paths into one optical signal and output it. Currently, there are three types of optical combiner devices for high-speed optical communication that are widely used: (1) Optical combiner devices based on Z-blocks, which are obtained by butterfly packaging or box packaging of Z-blocks. This type of optical combiner device has the disadvantages of high cost, complex process, and difficulty in miniaturization; (2) Optical combiner devices based on arrayed waveguide gratings (AWGs), which have strict requirements on wavelength selection, large insertion loss, and are also difficult to miniaturize; (3) Optical combiner devices based on filters, which are large in size and also difficult to miniaturize.

[0003] In order to meet the requirements of conventional TO-CAN packaging, the size of the optical path combiner chip needs to be greatly reduced, and the current optical path combiner chip is difficult to meet this requirement. Summary of the invention

[0004] The purpose of the present application is to provide an optical path combining chip structure and its application, wherein the optical path combining chip can be miniaturized and can meet the requirements of conventional TO-CAN packaging.

[0005] On the one hand, the present application provides an optical path combining chip structure, including an optical path combining module, an output light reflecting element and a pair of light source components; wherein the optical path combining module further includes:

[0006] A polarization beam splitter element having a beam splitting interface for reflecting polarized S light and transmitting polarized P light;

[0007] Two optical isolation units are arranged on both sides of the polarization beam splitter, each optical isolation unit comprises: a polarizer, a phase delay element, a reflective optical element, and a Faraday rotator arranged along the incident light path; the incident polarized light is converted into polarized S light after passing through the phase delay element and the Faraday rotator, and reaches the beam splitting interface in the state of polarized S light; and the backward transmission light is orthogonal to the polarization direction of the polarizer after passing through the Faraday rotator and the phase delay element; the reflective optical elements in the two optical isolation units are used to guide the respective incident polarized lights to the two sides of the beam splitting interface relatively;

[0008] A third phase delay element and a third reflective optical element are arranged along a reflective optical path of the beam splitting interface, the third reflective optical element is used to reflect the reflected polarized light from the beam splitting interface back to the beam splitting interface, and the third phase delay element is used to adjust the polarization direction of the reflected polarized light passing through so that the reflected polarized light reaches the beam splitting interface in a state of polarized P light;

[0009] A pair of light source components are used to generate incident polarized light and respectively enter two light isolation units;

[0010] The polarized light reflected by one side of the beam splitting interface and the polarized light transmitted from the other side of the beam splitting interface are combined with each other and output to the output light reflecting element.

[0011] In some specific embodiments, the two optical isolation units are symmetrically arranged on both sides of the polarization beam splitting element.

[0012] In some specific embodiments, the deflection angle of the reflective optical elements in the two light isolation units is 80° to 100°.

[0013] In some specific embodiments, the reflective optical element is a reflective prism.

[0014] In some specific embodiments, the phase delay element is a 1 / 2 wave plate, and the optical rotation angle of the Faraday rotator is configured to be 45°.

[0015] In some specific embodiments, the polarizer, phase delay element, and reflective optical element in each optical isolation unit are sequentially bonded and arranged along the second direction, wherein the reflective optical element and the Faraday rotator in one optical isolation unit are bonded and arranged along the first direction, and the reflective optical element and the Faraday rotator in the other optical isolation unit are bonded and arranged in the opposite direction of the first direction; and the Faraday rotators in the two optical isolation units are respectively bonded and arranged on both sides of the polarization splitting element; and the angle between the first direction and the second direction is 80° to 100°.

[0016] In some specific implementations, the reflective optical element is a reflective prism, and the phase delay element and the Faraday rotator in each optical isolation unit are respectively arranged in contact with two right-angled surfaces of the reflective optical element.

[0017] In some specific embodiments, the polarization angle of the third reflective optical element is 180°.

[0018] In some specific embodiments, the third reflective optical element is a high reflective mirror or a high reflective film.

[0019] In some specific embodiments, the third phase delay element is a quarter wave plate.

[0020] In some specific embodiments, the polarization beam splitting element is a PBS prism.

[0021] In some specific embodiments, the optical path combining chip structure further includes a base, and the polarization beam splitting element, the two optical isolation units, the third phase delay element, and the third reflective optical element are all disposed on the base.

[0022] In some specific embodiments, the output light reflecting element is a reflecting prism.

[0023] In some specific embodiments, the light sources in a pair of light source assemblies are both laser light sources; further, the light source of one light source assembly is an EML laser, and the light source of the other light source assembly is a DFB laser.

[0024] In some specific embodiments, the optical path combining chip structure further includes a pair of collimating optical elements, which are respectively arranged at the light emitting front ends of a pair of light source components to collimate the generated incident polarized light.

[0025] In some specific embodiments, the collimating optical element is a collimating lens made of silicon.

[0026] In some specific embodiments, the optical path combining chip structure further includes a packaging base, and the optical path combining module, the output light reflecting element and a pair of light source components are arranged on the packaging base; further, the packaging base is a TO62 base.

[0027] In some specific embodiments, a pair of light source assemblies each include a light source, a heater and an optical signal detection element, the light source and the optical signal detection element are arranged on the heater, and the optical signal detection element is used to monitor the working status of the light source.

[0028] In some embodiments, the light signal detecting element selects the backlight PD.

[0029] In some specific embodiments, a temperature detection element is also included to detect the operating temperature of the optical path combining chip.

[0030] In some specific implementations, a refrigerator is also included which is installed at the rear end of the optical path combining module.

[0031] In some specific implementations, a capacitive filter for filtering interference signals is further included.

[0032] On the other hand, the present application also provides the application of the above optical path combining chip structure in polarization multiplexing optical communication transmission.

[0033] Compared with the prior art, this application has the following advantages and beneficial effects:

[0034] 1. The optical path combining chip of this application can realize the one-way passage of optical signals and reverse cutoff, and has the function of optical isolator;

[0035] 2. The optical path combining chip of the present application has a wide applicable wavelength range and can be used within the effective working wavelength range of the polarization beam splitter and the Faraday rotator.

[0036] 3. The present application can realize reverse or nearly reverse light emission through optical path adjustment, that is, the direction of incident light is opposite or nearly opposite to that of outgoing light; compared with the current optical path combining device with forward light emission, reverse or nearly reverse light emission is conducive to optical path folding, so that the miniaturization of optical path combining module can be realized, which can meet the requirements of conventional TO-CAN packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 This is a schematic diagram of the structure of the optical path combining module in the embodiment of the present application;

[0039] Figure 2 for Figure 1 3D perspective view of the mid-path multiplexing module;

[0040] Figure 3 This is a schematic diagram of the optical transmission path of the first optical isolation unit in an embodiment of the present application;

[0041] Figure 4 This is a schematic diagram of the optical transmission path of the second optical isolation unit in an embodiment of the present application;

[0042] Figure 5 Schematic diagram of the structure of the optical path combining chip in this embodiment;

[0043] Figure 6 This is a schematic diagram of the optical transmission path of the optical combiner chip in this embodiment;

[0044] Figure 7 Schematic diagram of the three-dimensional structure of the optical path combining chip in this embodiment.

[0045] Reference numerals: optical path combining module 100, polarization beam splitter 110, light emitting surface 110a, beam splitting interface 111; first polarizer 121, first light input surface 121a, first phase delay element 122, first reflective optical element 123, first Faraday rotator 124, magnetic block 125; second polarizer 131, second light input surface 131a, second phase delay element 132, second reflective optical element 133, second Faraday rotator 134; third phase delay element 140, third reflective optical element 141; Optical element 150, base 160; output light reflecting element 200, first light source assembly 300a, first light source 310a, first heat 320a, first optical signal detection element 330a, second light source assembly 300b, second light source 310b, second heat 320b, second optical signal detection element 330b, first collimating optical element 400a, second collimating optical element 400b, packaging base 500, temperature detection element 600, filter 700, refrigerator 800, terminal 900. DETAILED DESCRIPTION

[0046] The following will be combined with the implementation methods of this application to clearly and completely describe the technical solutions in the implementation methods of this application. Obviously, the described implementation methods are only part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0047] Figures 3-4 FIG. 1 is a schematic diagram of a top view of an optical path combining module according to an embodiment of the present application. Figures 3-4 In the figure, we mark the XY rectangular coordinate system, and the positive and negative directions of the X axis are marked as "right" and "left", and the positive and negative directions of the Y axis are marked as "back" and "front". Figures 1 to 4 The structure and working principle of the optical path combining module in the embodiment of the present application are first described in detail.

[0048] In this embodiment, the optical path combining module includes a base 160, and a polarization splitter element 110, a first optical isolation unit, a second optical isolation unit, a third phase delay element 140 and a third reflective optical element 150 arranged on the base 160; the base 160 can be a ceramic base.

[0049] The polarization beam splitter 110 has a beam splitter interface 111 that reflects polarized S light and transmits polarized P light. The beam splitter interface 111 is inclined relative to both the X-axis and the Y-axis. In this embodiment, the angles between the beam splitter interface 111 and the positive directions of the X-axis and the Y-axis are both 45°. A light emitting surface 110a is provided at the front end of the polarization beam splitter 110, and the combined wave is output from the light emitting surface 110a. The polarization beam splitter 110 can be specifically selected from a PBS prism.

[0050] The two optical isolation units are respectively recorded as the first optical isolation unit and the second optical isolation unit, and are respectively arranged on both sides of the polarization beam splitter element 110. In the embodiment of the present application, the first optical isolation unit and the second optical isolation unit are symmetrically arranged on both sides of the polarization beam splitter element 110, and the first optical isolation unit and the second optical isolation unit respectively receive the first incident polarized light and the second incident polarized light, and the first incident polarized light and the second incident polarized light are relatively guided to the first surface and the second surface of the beam splitter interface 111. In the process of guiding the first incident polarized light and the second incident polarized light to the beam splitter interface 111, the two optical isolation units also convert the polarization state of the first incident polarized light and the second incident polarized light into polarized S light, and reach the beam splitter interface 111 in the state of polarized S light and are reflected.

[0051] In the present application, the first incident polarized light and the second incident polarized light both arrive at the beam splitting interface 111 in the state of polarized S light, and are respectively reflected by the first surface and the second surface of the beam splitting interface 111, forming two reflected light paths. The third phase delay element 140 and the third reflecting optical element 150 are arranged in sequence on one of the reflected light paths. In this embodiment, the third phase delay element 140 and the third reflecting optical element 150 are arranged in sequence on the reflected light path of the second surface of the beam splitting interface 111, and the reflected polarized light reflected by the second surface passes through the third phase delay element 140, the third reflecting optical element 150, and the third phase delay element 140 in sequence, and returns to the second surface of the beam splitting interface 111 again. In this process, the third phase delay element 140 rotates the polarization plane of the reflected polarized light twice, converts the reflected polarized light into polarized P light, and the reflected polarized light returns to the second surface of the beam splitting interface 111 in the state of polarized P light, and passes through the beam splitting interface 111. The optical rotation angle of the third phase delay element 140 is configured such that after rotating the polarization plane of the reflected polarized light twice, the reflected polarized light is converted into polarized P light. The third phase delay element 140 may be a quarter wave plate. The third reflective optical element 150 may be a high reflective mirror or a high reflective film to deflect the traveling direction of the reflected polarized light by 180°.

[0052] In the present application, the first optical isolation unit and the second optical isolation unit mainly play the role of transmitting incident polarized light and optical isolation. In this embodiment, the first optical isolation unit includes a first polarizer 121, a first phase delay element 122, a first reflective optical element 123, and a first Faraday rotator 124 arranged along the first incident light path L1; the first polarizer 121 has the same polarization direction as the first incident polarized light; the first reflective optical element 123 is used to guide the first incident polarized light to the first surface of the splitting interface 111; the first phase delay element 122 and the first Faraday rotator 124 are used to rotate the polarization planes of the first incident polarized light and the backward transmitted light; the rotation angles of the first phase delay element 122 and the first Faraday rotator 124 are configured to: make the first incident polarized light reach the splitting interface 111 in the state of polarized S light, and make the backward transmitted light perpendicular to the polarization direction of the first polarizer 121 when it reaches the first polarizer 121 in reverse. The backward transmission light is a light beam that is generated in the optical path and is transmitted in the reverse direction, which may have an adverse effect on the light source, etc. In the present application, the backward transmission light that reaches the first polarizer 121 cannot be transmitted from the first polarizer 121 because its polarization direction is perpendicular to the first polarizer 121, thereby achieving optical path isolation.

[0053] The second light isolation unit has the same structure as the first light isolation unit, and includes a second polarizer 131, a second phase delay element 132, a second reflective optical element 133, and a second Faraday rotator 134 arranged along the second incident light path L2; the structure and principle of the second light isolation unit are the same as those of the first light isolation unit, and are not repeated here.

[0054] In a magnetic field environment, the first Faraday rotator 124 and the second Faraday rotator 134 can rotate the polarization plane of polarized light. In this embodiment, a magnet is used to generate a magnetic field. For example, a magnetic block can be arranged at the top of each of the first Faraday rotator 124 and the second Faraday rotator 134, or a magnetic block 125 spanning the first Faraday rotator 124 and the second Faraday rotator 134 can be arranged at the top of the first Faraday rotator 124 and the second Faraday rotator 134.

[0055] In this embodiment, the first reflective optical element 123 and the second reflective optical element 133 are used to deflect the direction of the incident polarized light by 80° to 100°, and the deflected incident polarized light is relatively incident on two sides of the light splitting interface 111. The first reflective optical element 123 and the second reflective optical element 133 can be specifically reflective prisms.

[0056] In the first light isolation unit and the second light isolation unit, the first incident polarized light enters from the first light input surface 121a at the front end of the first polarizer 121, and the second incident polarized light enters from the second light input surface 131a at the front end of the second polarizer 131; the first phase delay element 122 and the second phase delay element 132 are used to rotate the polarization plane of the incident polarized light; the first reflecting optical element 123 and the second reflecting optical element 133 are used to change the traveling direction of the polarized light by reflection; the first Faraday rotator 124 and the second Faraday rotator 134 are used to rotate the polarization plane of the incident polarized light again, so that the polarized light is converted into polarized S light and reaches the two sides of the splitting interface 111.

[0057] In this embodiment, a possible specific layout of the optical path combining module is as follows:

[0058] The second reflecting optical element 133, the second Faraday rotator 134, the polarization beam splitter 110, the first Faraday rotator 124, and the first reflecting optical element 123 are sequentially arranged in affixed fashion along the first direction; the first polarizer 121, the first phase delay element 122, and the first reflecting optical element 123 are sequentially arranged in affixed fashion along the second direction; the second polarizer 131, the second phase delay element 132, and the second reflecting optical element 133 are sequentially arranged in affixed fashion along the second direction; the included angle between the first direction and the second direction is 80° to 100°. In this embodiment, the first direction and the second direction are the positive directions of the X and Y axes, and the included angle between the two is 90°. Selecting an included angle of 90° facilitates manufacturing and size reduction.

[0059] When the first reflective optical element 123 and the second reflective optical element 133 select reflective prisms, the first Faraday rotator 124 and the first phase delay element 122 are respectively arranged to fit the two right-angled surfaces of the first reflective optical element 123, and the second Faraday rotator 134 and the second phase delay element 132 are respectively arranged to fit the two right-angled surfaces of the second reflective optical element 133.

[0060] The working principle of the optical path combining module of the present application will be provided below in combination with embodiments.

[0061] In this embodiment, the first phase delay element 122 and the second phase delay element 132 are selected as 1 / 2 wave plates to rotate the polarization plane of the polarized light 45° counterclockwise; the rotation angles of the first Faraday rotator 124 and the second Faraday rotator 134 are configured to be 45° to rotate the polarization plane of the polarized light 45° counterclockwise; the first reflecting optical element 123 and the second reflecting optical element 133 are selected as reflecting prisms.

[0062] The first incident polarized light is recorded as λ1, which is horizontally polarized P light. The polarization direction of the first polarizer 121 is the same as that of the incident polarized light λ1. The incident polarized light λ1 is input from the first light input surface 121a at the front end of the first polarizer 121, and travels along the positive direction of the Y axis to reach the first phase delay element 122. The first phase delay element 122 rotates the polarization plane of the polarized light by 45° counterclockwise, and then passes through the first reflective optical element 123, and the traveling direction of the polarized light is changed to the opposite direction of the X axis. The first Faraday rotator 124 rotates the polarization plane of the polarized light by 45° counterclockwise again, and the horizontally polarized P light is converted into horizontally polarized S light. The horizontally polarized S light is incident on the first surface of the splitting interface 111 from the right side of the polarization beam splitter 110, and is reflected by the splitting interface 111, and is output from the light exit surface 110a at the front end of the polarization beam splitter 110 to obtain the first exit light, which is the horizontally polarized S light with the opposite polarization direction to the incident polarized light λ1.

[0063] The second incident polarized light is recorded as λ2, which is horizontally polarized P light. The polarization direction of the second polarizer 131 is the same as that of the incident polarized light λ2. The incident polarized light λ2 is input from the second light input surface 131a at the front end of the second polarizer 131, and travels along the positive direction of the Y axis to reach the second phase delay element 132. The second phase delay element 132 rotates the polarization plane of the polarized light by 45° counterclockwise, and then passes through the second reflective optical element 133, and the traveling direction of the polarized light is changed to the positive direction of the X axis; the second Faraday rotator 134 rotates the polarization plane of the polarized light by 45° counterclockwise again, and the horizontally polarized P light is converted into horizontally polarized S light. The horizontally polarized S light is incident from the left side of the polarization beam splitter 110 to the second surface of the beam splitter interface 111, is reflected by the beam splitter interface 111, travels in the positive direction along the Y-axis to the third phase delay element 140, is converted into circularly polarized light by the third phase delay element 140, and the third reflective optical element 150 is used to deflect the traveling direction of the circularly polarized light by 180°, and returns to the third phase delay element 140 again. The circularly polarized light is converted into linearly polarized P light, and is incident from the rear end of the polarization beam splitter 110 to the second surface of the beam splitter interface 111, passes through the beam splitter interface 111, and is output from the light exit surface 110a at the front end of the polarization beam splitter 110 to obtain a second exit light, which is a horizontally polarized P light in the opposite direction to the incident polarized light λ2.

[0064] When external reflected light enters, backward transmission light is generated. The polarization state of the backward transmission light is random and can be decomposed into polarized S light and polarized P light. The polarized S light is reflected by the first surface of the splitting interface 111 and enters the first light isolation unit in the reverse direction. The first Faraday rotator 124 rotates the reversely entering polarized S light counterclockwise by 45°. The first reflecting optical element 123 guides the polarized S light to the first phase delay element 122. The first phase delay element 122 rotates the polarized S light clockwise by 45°, which is offset by the rotation of the first Faraday rotator 124. The reversely entering polarized S light reaches the first polarizer 121 in the initial state. At this time, the polarized S light is perpendicular to the polarization direction of the first polarizer 121, thereby achieving light isolation.

[0065] The polarized P light in the backward transmitted light passes through the first surface of the splitter interface 111 and enters the third phase delay element 140. The third phase delay element 140 converts it into polarized S light. The third reflective optical element 150 guides it to the second surface of the splitter interface 111 again, and it is reflected by the second surface of the splitter interface 111 and enters the second optical isolation unit in the reverse direction. The second optical isolation unit implements optical isolation on it. The principle is the same as that of the first optical isolation unit, which will not be repeated here.

[0066] The horizontally polarized S light reflected by the first surface of the beam splitting interface 111 and the horizontally polarized P light transmitted through the second surface of the beam splitting interface 111 are combined with each other and output from the light output surface 110 a of the polarization beam splitting element 110 .

[0067] In the above embodiment, horizontally polarized P light is input, and completely orthogonal horizontally polarized P light and horizontally polarized S light are output, which can be applied to polarization multiplexing optical communication transmission.

[0068] In the above embodiments, the optical path is redesigned by using polarization beam splitters, phase delay elements (such as 1 / 2 wave plates, 1 / 4 wave plates), reflective optical elements and Faraday rotators to achieve reverse light emission, that is, the direction of incident polarized light is opposite to that of outgoing polarized light. Most existing optical path combining devices emit light in the forward direction. Compared with the forward light emission, the reverse light emission can achieve optical path folding, which provides a basis for greatly reducing the size of optical path combining modules and optical path combining chips, etc., and enables the miniaturization of optical path combining modules.

[0069] The size of the optical path combining module in the above embodiment can be controlled to 2.5mm*1.3mm, which is completely applicable to conventional TO-CAN packaging.

[0070] The above optical path combining module can be applied to the optical path combining chip. Figures 5 to 7, shown is the optical path combining chip in this embodiment, which mainly includes a package base 500, and an optical path combining module 100, an output light reflecting element 200, a first light source 310a and a second light source 310b arranged on the package base 500; the first light source 310a and the second light source 310b are used to generate a first incident polarized light and a second incident polarized light respectively; the optical path combining module 100 is used to combine the optical signal; the output light reflecting element 200 is used to change the traveling direction of the output light after the combination, so that it travels in a specific direction. In this embodiment, the package base 500 selects a TO62 base; the output light reflecting element 200 selects a 45-degree surface reflecting prism, which is arranged on the axis of the TO62 base; the first light source 310a and the second light source 310b are both laser light sources, specifically, the first light source 310a selects an EML laser, and the second light source 310b selects a DFB laser.

[0071] A first collimating optical element 400a and a second collimating optical element 400b are respectively disposed at the front ends of the first light source 310a and the second light source 310b to collimate the incident polarized light generated by the first light source 310a and the second light source 310b. In this embodiment, the first collimating optical element 400a and the second collimating optical element 400b are collimating lenses made of silicon.

[0072] In this embodiment, the first light source 310a and the second light source 310b are core components of the first light source assembly 300a and the second light source assembly 300b. Further, the first light source assembly 300a also includes a first radiator 320a and a first optical signal detection element 330a. The first radiator 320a is a high thermal conductivity ceramic substrate. The first light source assembly 300a and the first optical signal detection element 330a are arranged on the first radiator 320a. The first optical signal detection element 330a monitors the working state of the first light source 310a by detecting optical signals.

[0073] Similarly, the second light source assembly 300b also includes a second heat 320b and a second optical signal detection element 330b. The second heat 320b is a high thermal conductivity ceramic substrate. The second light source assembly 300b and the second optical signal detection element 330b are arranged on the second heat 320b. The second optical signal detection element 330b monitors the working status of the second light source 310b by detecting optical signals.

[0074] In this embodiment, the first optical signal detection element 330a and the second optical signal detection element 330b are respectively disposed at the rear ends of the first light source 310a and the second light source 310b; the first optical signal detection element 330a and the second optical signal detection element 330b both select the backlight PD.

[0075] In this embodiment, a temperature detection element 600, such as a thermistor, is installed on the packaging base 500 to detect the operating temperature of the optical path combining chip; a capacitor filter 700 is installed on the packaging base 500 to filter high-frequency interference signals; a cooler 800, such as a TEC semiconductor cooler, is installed at the rear end of the optical path combining module 100 to cool the optical path combining module 100; a plurality of terminals 900 are arranged on the packaging base 500, and the terminals 900 are gold wire bonding terminals, which are used to provide circuit driving, signal acquisition and other functions for chip components.

[0076] The working principle of the above-mentioned optical path combining chip is: the first light source 310a and the second light source 310b generate lasers, which are collimated by the first collimating optical element 400a and the second collimating optical element 400b and enter the optical path combining module 100 from the first light input surface 121a and the second light input surface 131a respectively. The first polarizer 121 and the second polarizer 131 are used to realize the passage of single polarized light, which is output from the light output surface 110a to the output light reflecting element 200 after being combined by the optical path combining module 100, and is reflected by the output light reflecting element 200 to be emitted in a direction perpendicular to the packaging base 500.

[0077] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present application, all of which belong to the protection scope of the present application.

Claims

1. An optical path combining chip structure, characterized by: It includes an optical path combining module, an outgoing light reflecting element and a pair of light source components; The optical path combining module further comprises: A polarization beam splitter element having a beam splitting interface for reflecting polarized S light and transmitting polarized P light; Two optical isolation units are arranged on both sides of the polarization beam splitter, each optical isolation unit comprises: a polarizer, a phase delay element, a reflective optical element, and a Faraday rotator arranged along the incident light path; the incident polarized light is converted into polarized S light after passing through the phase delay element and the Faraday rotator, and reaches the beam splitting interface in the state of polarized S light; and the backward transmitted light is orthogonal to the polarization direction of the polarizer after passing through the Faraday rotator and the phase delay element; the reflective optical elements in the two optical isolation units are used to guide the respective incident polarized lights to the two sides of the beam splitting interface relatively; A third phase delay element and a third reflective optical element are arranged along a reflective optical path of the beam splitting interface, the third reflective optical element is used to reflect the reflected polarized light from the beam splitting interface back to the beam splitting interface, and the third phase delay element is used to adjust the polarization direction of the reflected polarized light passing through so that the reflected polarized light reaches the beam splitting interface in a state of polarized P light; A pair of light source components are used to generate incident polarized light and respectively enter two light isolation units; The polarized light reflected by one side of the beam splitting interface and the polarized light transmitted from the other side of the beam splitting interface are combined with each other and output to the output light reflecting element.

2. The optical path combining chip structure according to claim 1, characterized in that: The deflection angle of the reflective optical elements in the two light isolation units is 80° to 100°.

3. The optical path combining chip structure according to claim 1, characterized in that: The phase delay element is a 1 / 2 wave plate, and the optical rotation angle of the Faraday rotator is configured to be 45°.

4. The optical path combining chip structure according to claim 1, characterized in that: The polarizer, phase delay element, and reflective optical element in each optical isolation unit are sequentially bonded and arranged along the second direction, wherein the reflective optical element and the Faraday rotator in one optical isolation unit are bonded and arranged along the first direction, and the reflective optical element and the Faraday rotator in the other optical isolation unit are bonded and arranged in the opposite direction of the first direction; and the Faraday rotators in the two optical isolation units are respectively bonded and arranged on both sides of the polarization beam splitting element; and the angle between the first direction and the second direction is 80° to 100°.

5. The optical path combining chip structure as claimed in claim 4, characterized in that: The reflective optical element is a reflective prism, and the phase delay element and the Faraday rotator in each optical isolation unit are respectively arranged in contact with two right-angle surfaces of the reflective optical element.

6. The optical path combining chip structure according to claim 1, characterized in that: The polarization angle of the third reflecting optical element is 180°.

7. The optical path combining chip structure as claimed in claim 6, characterized in that: The third reflective optical element is a high reflective mirror or a high reflective film.

8. The optical path combining chip structure according to claim 1, characterized in that: The third phase delay element is a quarter wave plate.

9. The optical path combining chip structure according to claim 1, characterized in that: The polarization beam splitting element is a PBS prism.

10. The optical path combining chip structure according to claim 1, characterized in that: The optical path combining module further includes a base, and the polarization beam splitting element, the two optical isolation units, the third phase delay element and the third reflective optical element are all arranged on the base.

11. The optical path combining chip structure according to claim 1, characterized in that: The output light reflecting element selects a reflecting prism.

12. The optical path combining chip structure according to claim 1, characterized in that: The light sources in the pair of light source assemblies are both laser light sources.

13. The optical path combining chip structure according to claim 12, characterized in that: In the pair of light source assemblies, the light source of one light source assembly is an EML laser, and the light source of the other light source assembly is a DFB laser.

14. The optical path combining chip structure according to claim 1, characterized in that: It also includes a pair of collimating optical elements, which are respectively arranged at the light emitting front ends of a pair of light source components and are used to collimate the generated incident polarized light.

15. The optical path combining chip structure according to claim 14, characterized in that: The collimating optical element is a collimating lens made of silicon.

16. The optical path combining chip structure according to claim 1, characterized in that: It also includes a packaging base, on which an optical path combining module, an outgoing light reflecting element and a pair of light source components are arranged.

17. The optical path combining chip structure according to claim 16, characterized in that: The package base is a TO62 base.

18. The optical path combining chip structure according to claim 1, characterized in that: The pair of light source components each include a light source, a heater and an optical signal detection element. The light source and the optical signal detection element are arranged on the heater, and the optical signal detection element is used to monitor the working state of the light source.

19. The optical path combining chip structure according to claim 18, characterized in that: The optical signal detecting element selects the backlight PD.

20. The optical path combining chip structure according to claim 1, characterized in that: It also includes a temperature detection element for detecting the working temperature of the optical path combining chip.

21. The optical path combining chip structure according to claim 1, characterized in that: It also includes a refrigerator installed at the rear end of the optical path combining module.

22. The optical path combining chip structure according to claim 1, characterized in that: A capacitive filter is also included to filter interference signals.

23. Application of the optical path combining chip structure as claimed in any one of claims 1 to 22 in polarization multiplexing optical communication transmission.

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