Same-side three-port full-temperature large-bandwidth two-stage isolation circulator

Abstract

The utility model relates to a same-side three-port full-temperature large-bandwidth two-stage isolation circulator, which comprises a three-fiber-core optical fiber, a collimating lens, a roof prism, a Z-Block module, a circulator core, a three-common-end optical fiber, a receiving end optical fiber, an input end optical fiber and the collimating lens, wherein the three-common-end optical fiber, the receiving end optical fiber, the input end optical fiber and the collimating lens are combined into a signal light common port, a receiving port and an input port which are positioned on the same side; the circulator core comprises a first polarization prism, a half-wave plate, a Faraday optical rotation crystal, a second polarization splitting prism and a turning prism, the right side of the cross section of the first polarization splitting prism is attached to the left side of the half-wave plate, and the half-wave plate and the Faraday optical rotation crystal form an optical rotation combination; an air gap exists between the left side of the second polarization splitting prism and the right side of the Faraday optical rotation crystal. The short bottom edge of the second polarization splitting prism is attached to the end face of the bottom edge of the turning prism. Organic combination of high isolation, high stability and high integration level is realized, and the problem of insufficient performance of a traditional circulator in a high-crosstalk complex environment in the prior art is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical circulators, and particularly relates to a full-temperature large-bandwidth dual-stage isolation optical circulator with three ports on the same side. Background Technique

[0002] An optical circulator is based on the Faraday magneto-optical effect. When light passes through a material with a non-zero magneto-optical tensor, its polarization state will be affected by an external magnetic field and change, realizing the directional propagation of multi-port input and output. It is widely used in devices such as radars, satellite communications, and radio stations. Its function is to make the optical signal can only be transmitted in the specified port order. When the optical signal is input from the specified port, it can only be output from the specified port in the device; when the transmission order of the optical signal changes, that is, when it is not transmitted according to the specified port, its loss is very large, and the isolation of the input signal can be realized.

[0003] In the design of traditional circulators, signals usually need to pass through multiple isolators to ensure the correct transmission and reception of signals. However, with the development of communication systems and the continuous improvement of requirements, the traditional circulator design can no longer fully meet the requirements of modern communication systems for high isolation, high stability, and high efficiency in some application scenarios. Moreover, the structure of traditional circulators is usually a three-port design, where one port is used for inputting signals, another port is used for outputting signals, and the third port is used for connecting loads. Although this design performs well in many applications, its inherent limitations begin to emerge when facing complex communication environments and higher performance requirements. For example, in the case of multi-signal interference, the isolation of traditional circulators may be insufficient, resulting in increased crosstalk and interference between signals, thus affecting the overall performance of the system. In addition, with the development of modern communication systems towards higher frequencies and larger bandwidths, the performance of traditional circulators often deteriorates significantly in the high-frequency range and cannot meet the requirements of high-speed data transmission.

[0004] To improve the isolation of the circulator, some designers have proposed the concept of multi-stage isolation, that is, introducing multiple isolators during the signal transmission process to enhance the isolation effect between signals. However, although this method improves the isolation to a certain extent, it also increases the complexity and cost of the system. Especially in the trend of high integration and miniaturization, this limits the cost and assembly space of the optical module, restricts the optical performance selection space, and makes this multi-stage isolation design appear more cumbersome and difficult to implement. And the environmental temperature during the use of the circulator is usually between -5°C and 75°C, and the rotation amount of the Faraday rotator crystal for the polarization state is greatly affected by temperature and wavelength. The widely existing circulators on the market cannot meet the high-isolation and low-crosstalk usage requirements for the full temperature and large bandwidth. In addition, the structures of the optical circulators on the market are mainly divided into two types: transmissive and reflective. The process of the transmissive optical circulator is relatively mature and the assembly is relatively simple. However, since its ports are distributed on both sides in the same transmission direction, its volume is relatively large. The reflective optical circulator uses the reflection principle, reduces the number of components in the structure, makes the structure more compact, and becomes an important direction for the miniaturization development of the optical circulator. Especially in data centers and 5G applications, it is necessary to install one or even multiple circulators in a limited space to achieve a multi-channel transceiver integrated module. In such applications, the size of the circulator becomes the most critical requirement. The same-side optical fiber output design can significantly reduce the demand for the optical fiber coiling space in the module, thereby further reducing the device size.

[0005] Facing the above challenges, designing a new type of circulator that can ensure high isolation while having higher integration, lower power consumption, and smaller volume has become an urgent problem to be solved in the industry. Summary of the Utility Model

[0006] The present utility model makes improvements to the above-mentioned problems existing in the prior art. That is, the technical problem to be solved by the present utility model is to provide a same-side three-port full-temperature large-bandwidth dual-stage isolation circulator.

[0007] To achieve the above object, the technical solution adopted by the present utility model is as follows: a full-temperature large-bandwidth double-stage isolation circulator with three ports on the same side, comprising a three-core optical fiber, a collimating lens, a roof prism, a Z-Block module, and a circulator core arranged in sequence. The three-core optical fiber includes a common-end optical fiber, a receiving-end optical fiber, and an input-end optical fiber. The common-end optical fiber, the receiving-end optical fiber, the input-end optical fiber, and the collimating lens are combined to form a signal light common port, a receiving port, and an input port on the same side. The circulator core includes a first polarization beam splitter prism, a half-wave plate, a Faraday rotator crystal, a second polarization beam splitter prism, and a turning prism. The right-end face of the cross-section of the first polarization beam splitter prism is attached to the left-end face of the half-wave plate. The half-wave plate and the Faraday rotator crystal are bonded together to form a rotator combination. There is an air gap between the left-end face of the second polarization beam splitter prism and the right-end face of the Faraday rotator crystal. The short-bottom-edge face of the second polarization beam splitter prism is attached to the bottom-edge face of the turning prism.

[0008] Further, the cross-section of the first polarization beam splitter prism is a parallelogram structure; the cross-section of the second polarization beam splitter prism is a right trapezoid structure with a base angle of 45°; the cross-section of the turning prism is an isosceles right triangle structure.

[0009] Further, a first polarization beam splitting film is provided inside the first polarization beam splitter prism; a second polarization beam splitting film is provided inside the second polarization beam splitter prism. The first polarization beam splitting film and the second polarization beam splitting film are used to separate or combine the P-polarized light and S-polarized light in the signal light.

[0010] Further, the first polarization beam splitting film is parallel to the upper and lower end faces of the first polarization beam splitter prism; the second polarization beam splitting film forms a 45° angle with the lower end face of the second polarization beam splitter prism and is parallel to the upper end face of the second polarization beam splitter prism. High-reflection films are provided on both the upper and lower end faces of the second polarization beam splitter prism.

[0011] Further, the cross-section of the roof prism is a roof-shaped structure with the top angle removed.

[0012] Further, the cross-section of the Z-Block module is a parallelogram structure. The Z-Block module includes a rhombic prism in the shape of a parallelogram. A reflecting sheet is attached to the left-end face of the rhombic prism, and a filter is attached to the right-side face of the rhombic prism.

[0013] Further, it further includes a glass outer envelope, a circulator core base, a magnetic ring, and a metal outer envelope. The circulator core base is a semi-circular structure and is used to fix the roof prism, the Z-Block module, and the circulator core. The glass outer envelope is a cylindrical structure. The circulator core base, the three-core optical fiber, and the collimating lens are all fixed inside the glass outer envelope. The magnetic ring is sleeved outside the glass outer envelope and corresponds to the position of the circulator core. The glass outer envelope is arranged inside the metal outer envelope.

[0014] Furthermore, the angle at which the signal light enters the circulator core is 1° to 4°.

[0015] Compared with the prior art, the present utility model has the following effects: The present utility model is reasonably designed, realizing the organic combination of high isolation, high stability and high integration, and overcoming the performance deficiencies of traditional circulators in the prior art in high crosstalk and complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a front view structural schematic diagram of an embodiment of the present utility model;

[0017] Figure 2 is a top view structural schematic diagram of an embodiment of the present utility model;

[0018] Figure 3 is a front view structural schematic diagram of the circulator core in an embodiment of the present utility model;

[0019] Figure 4 is a top view structural schematic diagram of the circulator core in an embodiment of the present utility model;

[0020] Figure 5 is a front view structural schematic diagram of the Z-Block module in an embodiment of the present utility model;

[0021] Figure 6 is a front view schematic diagram of the light propagation from the input end optical fiber to the lower end face of the second polarization beam splitter prism;

[0022] Figure 7 is a top view schematic diagram of the light propagation from the input end optical fiber to the lower end face of the second polarization beam splitter prism;

[0023] Figure 8 is a front view schematic diagram of the light propagation from the lower end face of the second polarization beam splitter prism to the common end optical fiber;

[0024] Figure 9 is a top view schematic diagram of the light propagation from the lower end face of the second polarization beam splitter prism to the common end optical fiber;

[0025] Figure 10 is a front view schematic diagram of the light propagation from the common end optical fiber to the turning prism;

[0026] Figure 11 is a top view schematic diagram of the light propagation from the common end optical fiber to the turning prism;

[0027] Figure 12 is a front view schematic diagram of the light propagation from the turning prism to the receiving end optical fiber;

[0028] Figure 13 A top view schematic diagram of the light propagation from the turning prism to the receiving end optical fiber;

[0029] Figure 14 A 3D schematic diagram (front view) of the optical path propagation from the input end optical fiber to the common end optical fiber;

[0030] Figure 15 A 3D schematic diagram (top view) of the optical path propagation from the input end optical fiber to the common end optical fiber;

[0031] Figure 16 A 3D schematic diagram (front view) of the optical path propagation from the common end optical fiber to the receiving end optical fiber;

[0032] Figure 17 A 3D schematic diagram (top view) of the optical path propagation from the common end optical fiber to the receiving end optical fiber;

[0033] Figure 18 A schematic diagram of the packaging structure of the embodiment of the present invention.

[0034] In the figure:

[0035] 101 - Common end optical fiber; 102 - Receiving end optical fiber; 103 - Input end optical fiber; 104 - Collimating lens; 105 - Roof prism; 106 - Z - Block module; 107 - Circulator core; 301 - First polarization beam splitter prism; 302 - Half - wave plate; 303 - Faraday rotator crystal; 304 - Second polarization beam splitter prism; 305 - Turning prism; 3011 - First polarization beam splitting film; 3012 - Second polarization beam splitting film; 401 - Reflective sheet; 402 - Rhombic prism; 403 - Filter; 1101 - Three - core optical fiber; 1102 - Metal outer encapsulation tube; 1104 - Glass outer encapsulation tube; 1105 - Circulator core base; 1106 - Magnetic ring;

[0036] Common port - Port1; Receiving port - Port3; Input port - Port2;

[0037] The bidirectional short arrow sign represents the polarization state of P - polarized light, and the dot represents the polarization state of S - polarized light. Detailed implementation manners

[0038] The following further elaborates on the present invention in detail in conjunction with the accompanying drawings and specific implementation manners.

[0039] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0040] As Figure 1 , 18 shown, a same-side three-port full-temperature large-bandwidth dual-stage isolation circulator of the present utility model includes a three-core optical fiber 1101, a collimating lens 104, a roof prism 105, a Z-Block module 106, and a circulator core 107 arranged in sequence. It also includes a glass outer envelope 1104, a circulator core base 1105, a magnetic ring 1106, and a metal outer envelope 1102. The circulator core base 1105 is of a semi-circular structure and is used to fix the roof prism 105, the Z-Block module 106, and the circulator core 107. The glass outer envelope 1104 is of a cylindrical structure, and the circulator core base 1105, the three-core optical fiber 1101, and the collimating lens 104 are all fixed inside the glass outer envelope 1104. The magnetic ring 1106 is sleeved outside the glass outer envelope 1104 and corresponds to the position of the circulator core 107 for providing a magnetic field. The glass outer envelope 1104 is arranged inside the metal outer envelope 1102, and the metal outer envelope 1102 is used to encapsulate the entire module.

[0041] In this embodiment, the three-core optical fiber 1101 and the collimating lens 104 form a three-core optical fiber collimator for providing collimated input or output of signal light in different bands. Specifically, the three-core optical fiber 1101 includes a common-end optical fiber 101, a receiving-end optical fiber 102, and an input-end optical fiber 103. The common-end optical fiber 101, the receiving-end optical fiber 102, the input-end optical fiber 103, and the collimating lens 104 are combined to form a signal light common port port1, a receiving port port3, and an input port port2 on the same side, which are used to emit or receive signal light of different wavelengths and transmit it to the circulator core 107.

[0042] In this embodiment, the roof prism 105 makes different turns for the transmitted signal light of different ports to match the optical path requirements. The Z-Block module 106 is used to couple and input and output signal light of different wavelengths, transmit the signal light transmitted from the input port to the circulator core 107 according to different wavelengths, and beam-combine the signal light returned by the circulator core 107 and transmit it to the common port or the receiving port.

[0043] In this embodiment, asFigure 3 As shown, the circulator core 107 includes a first polarization beam splitter prism 301, a half-wave plate 302, a Faraday rotator crystal 303, a second polarization beam splitter prism 304, and a turning prism 305. The cross-section of the first polarization beam splitter prism is a parallelogram structure. The end face on the right side of the cross-section of the first polarization beam splitter prism 301 is attached to the left end face of the half-wave plate 302. The half-wave plate 302 and the Faraday rotator crystal 303 are bonded together to form a rotator combination. When light propagates from left to right, the polarization direction rotates by 90°. When light propagates from right to left, the polarization direction does not rotate. The cross-section of the second polarization beam splitter prism 304 is a right trapezoid structure with a base angle of 45°. There is an air gap between the left end face of the second polarization beam splitter prism 304 and the right end face of the Faraday rotator crystal 303 without gluing. The cross-section of the turning prism 305 is an isosceles right triangle structure. The end face where the short base of the second polarization beam splitter prism 304 is located is attached to the end face where the base of the turning prism 305 is located.

[0044] In this embodiment, as Figure 3 shown, the first polarization beam splitter prism 301 is internally provided with a first polarization beam splitting film 3011 that divides the end face attached to the half-wave plate 302 into upper and lower parts. The first polarization beam splitting film 3011 is parallel to the upper and lower end faces of the first polarization beam splitter prism 301. High reflection films are provided on both the upper and lower end faces of the first polarization beam splitter prism 301. The second polarization beam splitter prism 304 is internally provided with a second polarization beam splitting film 3012 that divides the end face attached to the Faraday rotator crystal 303 into upper and lower parts. The second polarization beam splitting film 3012 forms an angle of 45° with the lower end face of the second polarization beam splitter prism 304 and is parallel to the upper end face of the second polarization beam splitter prism 304. High reflection films are provided on both the upper and lower end faces of the second polarization beam splitter prism 304. The first polarization beam splitting film 3011 and the second polarization beam splitting film 3012 are used to separate or combine the P-polarized light and S-polarized light in the signal light.

[0045] In this embodiment, the common port Port1, the receiving port Port3, and the input port Port2 are all located on the left end face of the first polarization beam splitter prism.

[0046] In this embodiment, the cross-section of the roof prism 105 is a roof-shaped structure with the top angle cut off, which is used to transmit three-port signal light.

[0047] In this embodiment, as Figure 4As shown, the cross-section of the Z-Block module 106 is a parallelogram structure. The Z-Block module 106 includes a reflector 401, a rhombic prism 402 in the shape of a parallelogram, and a filter 403. The reflector 401 is attached to the left end face of the rhombic prism 402, and the filter 403 is attached to the right end face of the rhombic prism 403. The angle of the rhombic prism 402 is set to 76.5°. The filter is used to transmit the signal light of one wavelength and reflect the signal light of other wavelengths. The Z-Block module is used to combine or split the signal lights of different wavelengths.

[0048] In this embodiment, the angle at which the signal light enters the circulator core 107 is 1 to 4°.

[0049] In this embodiment, the positions of the half-wave plate 302 and the Faraday rotator crystal 303 can be interchanged.

[0050] In this embodiment, antireflection films are provided on all the bonding surfaces and the signal port surfaces.

[0051] Specific implementation process:

[0052] (1) As shown in Figure 5 After the signal light is emitted from the input optical fiber 103, it is collimated by the collimating lens 104 and then transmitted to the roof prism 105, and then transmitted to the Z-Block module 106. The signal light is divided into four beams according to different wavelength bands and jointly transmitted to the common port Port1 of the circulator core 107 (Note: Since the signal lights of different wavelength bands have the same transmission mode in the circulator core, only the spatial positions are different, so only one beam will be described subsequently). The signal light enters the first polarization beam splitter prism 301 from the common port Port1. After being transmitted to the first polarization beam splitting film 3011, the P-polarized light in the signal light is transmitted, and the S-polarized light is reflected. The P-polarized light is reflected by the lower end face of the first polarization beam splitter prism 301. After the P-polarized light and the S-polarized light pass through the half-wave plate 302 and the Faraday rotator crystal 303 respectively, the polarization directions of both change. The original P-polarized light becomes S-polarized light, and the original S-polarized light becomes P-polarized light. The rotated P-polarized light enters the second polarization beam splitter prism 304 and passes through the second polarization beam splitting film 3012; the rotated S-polarized light enters the second polarization beam splitter prism 304 and is reflected by the second polarization beam splitting film 3012. Then, the P-polarized light and the S-polarized light are combined and transmitted to the lower end face of the second polarization beam splitter prism 304.

[0053] (2) As shown in Figure 6As shown, the signal light is reflected by the lower end face of the second polarization beam splitter prism 304 and then transmitted to the second polarization beam splitting film 3012. The P-polarized light in the signal light is transmitted, and the S-polarized light is reflected. The P-polarized light is reflected by the upper end face of the second polarization beam splitter prism 304. After the P-polarized light and the S-polarized light pass through the Faraday rotator crystal 303 and the half-wave plate 302 respectively, the polarization directions of both remain unchanged. The P-polarized light enters the first polarization beam splitter prism 301 and is transmitted by the first polarization beam splitting film 3011; the S-polarized light enters the first polarization beam splitter prism 301, is reflected by the lower end face of the first polarization beam splitter prism 301 and then reflected by the first polarization beam splitting film 3011. The two are combined and transmitted to the signal port Port2. Four signal lights with different wavelengths are transmitted from the signal input port Port2 to the Z-Block module 106, combined and then transmitted to the roof prism 105, and then transmitted to the common-end optical fiber 101 through the collimating lens 104.

[0054] (3) As Figure 7 As shown, after the signal light is emitted from the common-end optical fiber 101, it is collimated by the collimating lens 104 and then transmitted to the roof prism 105, and then transmitted to the Z-Block module 106. The signal light is divided into four beams according to different wavelengths and jointly transmitted to the signal input port Port2 of the circulator core 107. The signal light enters the first polarization beam splitter prism 301 from the signal input port Port2. After being transmitted to the first polarization beam splitting film 3011, the P-polarized light in the signal light is transmitted, and the S-polarized light is reflected. The S-polarized light is reflected by the lower end face of the first polarization beam splitter prism 301. After the P-polarized light and the S-polarized light pass through the half-wave plate 302 and the Faraday rotator crystal 303 respectively, the polarization directions of both change. The original P-polarized light becomes S-polarized light, and the original S-polarized light becomes P-polarized light. The rotated P-polarized light enters the second polarization beam splitter prism 304 and passes through the second polarization beam splitting film 3012; the rotated S-polarized light enters the second polarization beam splitter prism 304, is reflected by the upper end face of the second polarization beam splitter prism 304 and then reflected by the second polarization beam splitting film 3012. The P-polarized light and the S-polarized light are combined and transmitted to the end face where the short bottom edge of the second polarization beam splitter prism 304 is located, and further transmitted to the turning prism 305.

[0055] (4) As Figure 8As shown, after the signal light is refracted by the turning prism 305 and transmitted to the second polarization beam splitting film 3012 of the second polarization beam splitter prism 304, the P-polarized light in the signal light is transmitted, and the S-polarized light is reflected. The S-polarized light is reflected by the upper end face of the second polarization beam splitter prism 304. After the P-polarized light and the S-polarized light pass through the Faraday rotator crystal 303 and the half-wave plate 302 respectively, the polarization directions of both remain unchanged. The P-polarized light enters the first polarization beam splitter prism 301 and is transmitted by the first polarization beam splitting film 3011 after being reflected by the lower end face of the first polarization beam splitter prism 301; after the S-polarized light enters the first polarization beam splitter prism 301, it is reflected by the first polarization beam splitting film 3011, and the two are combined and reflected by the upper end face of the first polarization beam splitter prism 301 and then transmitted to the signal receiving port Port3. Four signal lights with different wavelength bands are transmitted from the signal receiving port Port3 to the Z-Block module 106, combined and then transmitted to the roof prism 105, and then transmitted to the receiving end optical fiber 102 through the collimating lens 104.

[0056] Through innovative design, the circulator realizes the organic combination of high isolation, high stability and high integration, overcoming the performance deficiencies of traditional circulators in high crosstalk and complex environments in the prior art. The purpose of the present utility model is to improve the transmission efficiency and quality of signals through a simple and effective design, while reducing the overall power consumption and cost of the system. The same-side three-port full-temperature large-bandwidth dual-stage isolation circulator of the present utility model adopts a unique dual-stage isolation structure. Specifically: by introducing a dual-stage isolation optical path scheme in the signal transmission path, it is necessary to pass through two Faraday rotator crystals during the signal transmission at different ports. This design enables the signal to effectively reduce crosstalk and interference during transmission, improving the overall isolation of the system. Compared with the traditional multi-stage isolation design, the dual-stage isolation structure of the present utility model has higher integration and lower implementation difficulty, and is particularly suitable for the miniaturization and high integration requirements of modern communication devices. The same-side three-port full-temperature large-bandwidth dual-stage isolation circulator adopts a special optical path design, so that the three ports of the circulator are all located on the same side, greatly reducing the size of the circulator and meeting the requirements of modern communication devices for lightweight and miniaturization. In addition, the circulator fully considers the different polarization state rotation amounts of the Faraday rotator crystal at different temperatures and different wavelengths in the design. Different thicknesses of Faraday rotator crystals are matched according to different wavelengths and temperature ranges in the optical path design to correct the insertion loss and isolation problems of the system caused by different wavelengths and temperatures. By optimizing the optical path design and material selection, the power consumption of the circulator is effectively reduced, thereby extending the service life of the device and improving the reliability of the system.

[0057] The advantages of the present utility model are as follows:

[0058] (1)High isolation: Through a dual-stage isolation optical path structure, the signal isolation between ports is significantly improved, thereby reducing the occurrence of signal crosstalk and interference;

[0059] (2)High integration: Through innovative structural design and advanced manufacturing processes, a high-integration circulator design is achieved, enabling a significant reduction in the size of the circulator, which meets the miniaturization requirements of modern communication devices;

[0060] (3)Low power consumption: Optimization is carried out in material selection and optical path design, significantly reducing the power consumption of the circulator, thereby extending the service life of the device and improving the reliability of the system;

[0061] (4)Wide bandwidth: The design fully considers the usage requirements of large bandwidth, high and low temperatures. By matching Faraday rotator crystals of different thicknesses, stable operation within a large bandwidth, high and low temperature ranges is ensured.

[0062] (5)Easy to implement: Compared with traditional multi-stage isolation designs, the dual-stage isolation structure of the present utility model has significant advantages in terms of implementation difficulty and manufacturing cost, facilitating large-scale production and application.

[0063] The same-side three-port full-temperature large-bandwidth dual-stage isolation circulator of the present utility model is applicable to a variety of modern communication systems, including but not limited to satellite communication, radar systems, wireless communication base stations, etc. By adopting the circulator of the present invention, the performance of the communication system can be effectively improved, the power consumption and cost of the system can be reduced, and it has broad application prospects.

[0064] It should be noted that in actual applications, the circulator can be combined with other optical module devices to further improve the overall performance of the system. For example, the circulator of the present invention can be integrated with devices such as filters and amplifiers to construct a high-performance RF front-end module for use in high-demand communication systems. Through the technical solution of the present invention, the transmission quality of signals and the reliability of the system can be significantly improved without increasing the complexity and cost of the system. It meets the higher requirements of optical communication modules (transceivers) for isolation, insertion loss, and return loss, ensuring that the return loss of each channel > 70 dB, the optical paths of P light and S light inside the circulator core are consistent, the PMD loss is low, which is of great help to the improvement of the performance and cost reduction of optical communication modules (transceivers), and the same-side design makes the overall circulator more miniaturized, facilitating compact structural design.

[0065] If the present utility model discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, using bolts or screws for connection), or can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the components fixedly connected to each other can also be replaced by an integral structure (for example, manufactured by integral forming using a casting process) (except where it is clearly impossible to use the integral forming process).

[0066] In addition, for any technical solution disclosed in the present utility model above, the terms used to represent the positional relationship or shape, unless otherwise stated, include states or shapes that are approximate, similar, or close to them.

[0067] Any component provided by the present utility model can either be assembled from a plurality of separate components or be a single component manufactured by an integral forming process.

[0068] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them; although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present utility model or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present utility model, they should all be covered within the scope of the technical solutions claimed by the present utility model.

Claims

1. A same-side three-port full-temperature wide-bandwidth dual-stage isolated circulator, characterized in that: It includes a three-core optical fiber, a collimating lens, a roof prism, a Z-Block module and a circulator core arranged in sequence. The three-core optical fiber includes a common-end optical fiber, a receiving-end optical fiber and an input-end optical fiber. The common-end optical fiber, the receiving-end optical fiber, the input-end optical fiber and the collimating lens are combined to form a signal light common port, a receiving port and an input port on the same side. The circulator core includes a first polarization beam splitter prism, a half-wave plate, a Faraday rotator crystal, a second polarization beam splitter prism and a turning prism. The right-end face of the cross-section of the first polarization beam splitter prism is attached to the left-end face of the half-wave plate. The half-wave plate and the Faraday rotator crystal are attached together to form a rotator combination. There is an air gap between the left-end face of the second polarization beam splitter prism and the right-end face of the Faraday rotator crystal. The short-bottom-edge face of the second polarization beam splitter prism is attached to the bottom-edge face of the turning prism.

2. The same-side three-port full-temperature large-bandwidth dual-stage isolated circulator according to claim 1, wherein: The cross-section of the first polarization beam splitter prism is a parallelogram structure; the cross-section of the second polarization beam splitter prism is a right trapezoid structure with a bottom angle of 45°; the cross-section of the turning prism is an isosceles right triangle structure.

3. The same-side three-port full-temperature large-bandwidth dual-stage isolated circulator according to claim 2, characterized in that: The first polarization beam splitter prism is internally provided with a first polarization beam splitting film; the second polarization beam splitter prism is internally provided with a second polarization beam splitting film. The first polarization beam splitting film and the second polarization beam splitting film are used to separate or synthesize the P-polarized light and S-polarized light in the signal light.

4. The same-side three-port full-temperature wide-bandwidth double-stage isolated circulator according to claim 3, characterized in that: The first polarization beam splitting film is parallel to the upper and lower end faces of the first polarization beam splitter prism; the second polarization beam splitting film forms an angle of 45° with the lower end face of the second polarization beam splitter prism, and the second polarization beam splitting film is parallel to the upper end face of the second polarization beam splitter prism. High-reflection films are provided on both the upper and lower end faces of the second polarization beam splitter prism.

5. The same-side three-port full-temperature large-bandwidth dual-stage isolated circulator according to claim 1, characterized in that: The cross-section of the roof prism is a roof-shaped structure with the top angle removed.

6. The same-side three-port full-temperature large-bandwidth dual-stage isolated circulator according to claim 1, characterized in that: The cross-section of the Z-Block module is a parallelogram structure. The Z-Block module includes a rhomboid prism in the shape of a parallelogram. A reflector is attached to the left-end face of the rhomboid prism, and a filter is attached to the right-side face of the rhomboid prism.

7. The same-side three-port full-temperature wide-bandwidth dual-stage isolated circulator according to claim 1, characterized in that: It also includes a glass outer envelope, a circulator core base, a magnetic ring and a metal outer envelope. The circulator core base is a semi-circular structure and is used to fix the roof prism, the Z-Block module and the circulator core. The glass outer envelope is a cylindrical structure. The circulator core base, the three-core optical fiber and the collimating lens are all fixed inside the glass outer envelope. The magnetic ring is sleeved outside the glass outer envelope and corresponds to the position of the circulator core. The glass outer envelope is arranged inside the metal outer envelope.

8. The same-side three-port full-temperature wide-bandwidth dual-stage isolated circulator according to claim 1, characterized in that: The angle at which the signal light enters the circulator core is 1 to 4°.

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