Silicon Optical Isolator Engine

Abstract

The present invention discloses a silicon optical isolator engine that can transmit optical signals of any polarization state and can keep the polarization state of the output optical signal consistent with the polarization state of the input signal. The silicon optical isolator engine includes a mother substrate, on which a first sub-substrate, a second sub-substrate, a third sub-substrate, a fourth sub-substrate, a fifth sub-substrate, and a sixth sub-substrate are arranged in sequence from one end of the mother substrate to the other end; a silicon optical and waveguide group is arranged on the first sub-substrate; a tapered optical fiber is arrayed on the second sub-substrate; a first lens is arrayed on the third sub-substrate; an isolator shared by all channels is arranged at one end of the fourth sub-substrate; a half-wavelength glass slide is arranged at the other end; a second lens is arrayed on the fifth sub-substrate; and a single-fiber optical fiber head is arrayed on the sixth sub-substrate. The silicon optical isolator engine has small optical signal dispersion, which can ensure high signal integrity; it has multiple channels to transmit signals, which can improve system redundancy.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber communication, and in particular to a silicon optical isolator engine. Background Art

[0002] With the rapid development of optical communication technology and the widespread application of wavelength division multiplexing technology, devices used for optical signal transmission and processing are developing towards high integration, and highly integrated laser modules have emerged. However, after the light comes out of the laser, the polarization state will change uncontrollably during the subsequent optical fiber propagation, and it cannot be used in fiber interferometers and some fiber lasers that do not allow the polarization state to change, which in turn affects the use effect. In addition, when the light wave signal passes through the connector end face, 4% of the light will return to the original optical path, affecting the performance of the laser and reducing the quality of the optical path signal. In addition, because the refractive index and speed of O light and E light in the polarizer crystal used in the online isolator connected to the existing laser module are different, the optical signal dispersion is large after passing through the isolator. In optical communications at 100G or higher speeds, the integrity and fidelity of the signal are greatly affected.

[0003] Currently, the most widely used isolators on the market are polarization-dependent free-space isolators. Figure 1 As shown, the free space isolator consists of a polarizer, a Faraday rotator, and an analyzer. The light after passing through the polarizer has only one polarization state, such as a 90° polarization state. After being rotated 45° by the Faraday rotator, the polarized light rotates 45 degrees and then passes through the analyzer. At this time, the polarization state of the light becomes 45°. If the polarization state of light is used as information transmission, then this isolator can only transmit one polarization state information.

[0004] Another polarization-independent inline isolator on the market consists of a collimator and an isolator core. Figure 2 The isolator principle is to use the birefringence of LiNbO3 crystal to O light and E light to achieve the isolator effect. Because the speed of O and E light is different during birefringence in LiNbO3 crystal, the PMD of the device is large, which is easy to cause signal distortion in 100G or higher rate optical communication. In addition, in this solution, since the Faraday rotator rotates the polarization state of light by 45 degrees, the device still cannot guarantee the polarization consistency of the incoming and outgoing light. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a silicon optical isolator engine that can transmit optical signals in any polarization state and ensure that the polarization state of the light coming out of the silicon optical system remains unchanged after passing through the isolator module, that is, the polarization state of the input and output light is consistent, the dispersion is small, and the PMD is almost 0, thereby ensuring signal integrity and improving system redundancy.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a silicon optical isolator engine comprises a mother substrate, on which a first sub-substrate, a second sub-substrate, a third sub-substrate, a fourth sub-substrate, a fifth sub-substrate and a sixth sub-substrate are arranged in sequence from one end of the mother substrate to the other end;

[0007] A silicon light and waveguide group is disposed on the first sub-substrate; the silicon light and waveguide group is evenly distributed vertically; and each silicon light and waveguide group includes a silicon chip and a waveguide;

[0008] The second sub-substrate is arrayed with tapered optical fibers;

[0009] The third sub-substrate is provided with an array of first lenses;

[0010] An isolator common to all channels is arranged at one end of the fourth sub-base plate; a half-wavelength glass plate is arranged at the other end; the isolator comprises a positive crystal wedge, a GMF Faraday plate, and a negative crystal wedge arranged in sequence laterally;

[0011] The fifth sub-substrate is provided with a second lens array;

[0012] The sixth sub-base plate is arrayed with single-fiber optical fiber heads; the single-fiber optical fiber heads are connected to polarization-maintaining optical fibers;

[0013] The silicon optical waveguide group, the tapered optical fiber, the first lens, the second lens, and the single-fiber optical fiber head correspond one to one.

[0014] Furthermore, the positive crystal wedge and the negative crystal wedge are both made of birefringent crystals, and both have an inclined surface and a vertical surface; the inclined surfaces of the two are parallel;

[0015] The vertical plane is S1; the optical axis of the positive crystal wedge is the optical axis A, the optical axis of the negative crystal wedge is the optical axis B, and the optical axes A and B form an angle of 45°.

[0016] Furthermore, the half-wavelength glass slide adopts a birefringent crystal, and the optical axis of the half-wavelength glass slide is in the horizontal direction of the forward light.

[0017] Furthermore, one end of the polarization-maintaining optical fiber is connected to an optical fiber connector, and the optical fiber connector can be made into MT, FC / PC, FC / APC, LC / PC, LC / APC or other types of optical fiber connectors as needed.

[0018] Furthermore, a first fixed optical fiber head is provided at one end of the tapered optical fiber, and a second fixed optical fiber head is provided at the other end; the second fixed optical fiber head has an inclined 8-degree surface that is flush with the inclined 8-degree surface of the first lens.

[0019] The beneficial effects of the present invention are as follows: the silicon optical isolator engine described in the present invention adopts polarization-maintaining optical fiber and polarization-independent isolator, so the system can transmit optical signals of any polarization state, and can ensure that the light coming out of the silicon optical still maintains the polarization state unchanged after passing through the isolator. Secondly, since the system includes positive crystal wedges, GMF Faraday plates, negative crystal wedges and half-wavelength glass plates arranged in sequence laterally, the total optical path difference of o-light and e-light transmitted in the crystal is kept consistent through the joint action of the positive crystal wedges, GMF Faraday plates, negative crystal wedges and half-wavelength glass plates, that is, the dispersion of the overall system when transmitting optical signals is small (almost PMD=0), and the signal integrity can be guaranteed; finally, having multiple channels to transmit signals of the same or different wavelengths can improve the system redundancy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the optical path principle of the polarization-dependent free-space isolator in the prior art;

[0021] Figure 2 It is a schematic diagram of the structure of a polarization-independent online isolator in the prior art;

[0022] Figure 3 A schematic diagram of the structure of a silicon optical isolator engine in an embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram of direct coupling of light coming out of a waveguide with an optical fiber having a cylindrical flat end face in the prior art;

[0024] Figure 5 It is a schematic diagram of the prior art that the light coming out of the waveguide is directly coupled to the optical fiber with a cylindrical flat end face through a lens;

[0025] Figure 6 Schematic diagram of direct coupling of light from a waveguide with a tapered optical fiber in an embodiment of the present invention;

[0026] Figure 7 Schematic diagram of the structure of a tapered optical fiber in an embodiment of the present invention;

[0027] Figure 8 An exploded schematic diagram of an isolator in an embodiment of the present invention;

[0028] Fig. 9 Schematic diagram of forward light transmission and reverse light transmission of an isolator in an embodiment of the present invention;

[0029] Fig.10 Schematic diagram of the optical axis angle between the positive crystal wedge and the negative crystal wedge of the isolator in an embodiment of the present invention;

[0030] Fig.11This is a structural view of debugging and installing the second sub-substrate and the third sub-substrate on the mother substrate 1 in an embodiment of the present invention;

[0031] Fig.12 For Fig.11 A schematic diagram of debugging and installing the first sub-baseboard on the basis of;

[0032] Fig.13 For Fig.12 A schematic diagram of debugging and installing the fifth sub-baseboard and the sixth sub-baseboard on the basis of FIG.

[0033] Fig.14 It is a structural schematic diagram of an isolator in an embodiment of the present invention;

[0034] Fig.15 A schematic diagram of a testing system for an isolator according to an embodiment of the present invention;

[0035] Fig.16 A schematic diagram of testing an isolator in an embodiment of the present invention;

[0036] Fig.17 It is a schematic diagram of the structure of the silicon optical isolator engine after debugging in an embodiment of the present invention.

[0037] Markings in the figure: 1-mother substrate, 10-first sub-substrate, 20-second sub-substrate, 30-third sub-substrate, 40-fourth sub-substrate, 80-fifth sub-substrate, 90-sixth sub-substrate, 4-positive crystal wedge, 5-GMF Faraday plate, 6-negative crystal wedge, 7-half wavelength glass slide. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0039] like Figures 1 to 16 As shown, the silicon optical isolator engine of the present invention comprises a mother substrate 1, on which a first sub-substrate 10, a second sub-substrate 20, a third sub-substrate 30, a fourth sub-substrate 40, a fifth sub-substrate 80, and a sixth sub-substrate 90 are sequentially arranged from one end of the mother substrate 1 to the other end;

[0040] The first sub-substrate 10 is provided with a silicon light and waveguide group; the silicon light and waveguide group are evenly distributed vertically; and each silicon light and waveguide group includes a silicon chip 101 and a waveguide 102;

[0041] The second sub-substrate 20 is arrayed with tapered optical fibers 201;

[0042] The third sub-substrate 30 is provided with an array of first lenses 301;

[0043] An isolator common to all channels is arranged at one end of the fourth sub-substrate 40; a half-wavelength glass plate 7 is arranged at the other end; the isolator includes a positive crystal wedge 4, a GMF Faraday plate 5, and a negative crystal wedge 6 which are arranged in sequence in a transverse direction;

[0044] The fifth sub-substrate 80 is provided with an array of second lenses 801;

[0045] The sixth sub-base plate 90 is arrayed with single-fiber optical fiber heads 902; the single-fiber optical fiber heads 902 are connected to polarization-maintaining optical fibers 901;

[0046] The silicon optical waveguide group, the tapered optical fiber 201, the first lens 301, the second lens 801, and the single-fiber optical fiber head 902 correspond one to one.

[0047] Specifically, the positive crystal wedge 4 and the negative crystal wedge 6 are both made of birefringent crystals, and both have an inclined surface and a vertical surface; the inclined surfaces of the two are parallel;

[0048] The vertical plane is S1; the optical axis of the positive crystal wedge 4 is the optical axis A, the optical axis of the negative crystal wedge 6 is the optical axis B, and the optical axes A and B form an angle of 45°.

[0049] Specifically, the half-wavelength glass slide 7 adopts a birefringent crystal, and the optical axis of the half-wavelength glass slide 7 is in the horizontal direction of the forward light. One end of the polarization-maintaining optical fiber 901 is connected to the optical fiber connector. One end of the tapered optical fiber 201 is provided with a first fixed optical fiber head 202 and the other end is provided with a second fixed optical fiber head 203; the second fixed optical fiber head 203 has an inclined 8-degree surface that is flush with the inclined 8-degree surface of the first lens 301.

[0050] refer to Figure 3 In the silicon photonics and waveguide array, the silicon chip 101 of the first channel emits a linearly polarized light with a wavelength of λ1. Assuming the polarization state is 90°, this linearly polarized light is coupled into the waveguide 102, and then the waveguide 102 undergoes mode conversion through multiple forward Taper reflections and multiple reverse Taper reflections before being coupled into the tapered optical fiber 201.

[0051] The coupling between the light coming out of the waveguide and the optical fiber is essentially the mode field matching between the two. Figure 4 In the existing scheme, a cylindrical flat-end optical fiber is used for direct coupling. Due to the mode field mismatch, the coupling efficiency is very low, about 10%. Therefore, the existing improvement scheme is as follows Figure 5 , is to add a lens here, and couple the light into the cylindrical optical fiber through the matching of the lens. Figure 6The present invention uses a tapered optical fiber for direct coupling of light waves, which can improve coupling efficiency, save the use of lenses, and reduce costs. The characteristic of the tapered optical fiber is that the diameters of the cladding and the core of the optical fiber gradually become thinner along the axial direction of the optical fiber. It can be considered that the ratio of the diameter of the cladding to the core is kept constant in the entire tapered area.

[0052] Figure 7 It is a cross-sectional view of a tapered optical fiber. α1 and α2 are different optical fiber tapers. L1 and L2 are the lengths of the optical cone corresponding to different tapers. a1 and a2 are the thick end radii of the optical fiber cone, and b1 and b2 are the tip radii.

[0053] Since two parallel lines are intercepted by a third line, the interior alternate angles are equal, so we can infer that α3 = α1, α4 = α2, so we have:

[0054]

[0055] From the geometric diagram we can see that:

[0056] b1 <b2α1<α2L1> L2

[0057] It can be seen that when the diameter and material of the optical fiber have been set, the larger the tip radius b, the larger the cone angle α; the shorter the tapered transition zone of the optical fiber, the smaller the light cone length L, the larger the cone angle α, and the greater the cone change.

[0058] When making a tapered optical fiber, by controlling the parameters of the tip radius b and the light cone length L, the mode field of the light wave transmitted to the tip of the light cone is matched with the mode field of the light coming out of the waveguide, so that the insertion loss coupling is minimized.

[0059] The present invention uses a tapered optical fiber for light coupling, which not only improves the coupling efficiency, but also saves the use of lenses, thereby reducing costs and process difficulty.

[0060] Since ordinary optical fibers will cause uncontrollable changes in the polarization state of light waves when propagating light waves. In order to keep the polarization state of the linearly polarized light coming out of the silicon optical fiber and the waveguide array unchanged, the tapered optical fiber in the present invention uses a polarization-maintaining optical fiber (polarization-maintaining optical fiber (PMF or PM optical fiber) is an optical fiber in which the polarization of the internal input linear polarization-maintaining light wave does not change during the propagation inside the optical fiber, or in other words, there is only a small (or preferably no) cross-coupling between the polarization modes of the internal optical fiber). Therefore, after the linear polarized light λ1 with a polarization state of 90° propagates through the polarization-maintaining optical fiber, the wavelength and polarization state remain unchanged, and it is still the wavelength λ1 and the polarization state is 90°.

[0061] Furthermore, the tapered fiber array includes four optical fibers, and one end of each optical fiber coupled to the silicon optical array is tapered to improve coupling efficiency. The core of the other end of the first optical fiber 201 of the first channel is at the focus of the lens 301. The core on the right side of the optical fiber of each channel is at the focus of the lens of the channel. Because the light coming out of the optical fiber core is divergent light, after propagating through the focus of the lens, it becomes collimated parallel light after being collimated by the lens. In order to reduce the return loss, the tapered fiber array and the lens connection surface are both inclined at 8 degrees for light coupling.

[0062] At this time, the linearly polarized light with a wavelength of λ1 that passes through the first lens is collimated linearly polarized light, and the polarization state is still 90°.

[0063] The crystal wedge 4, the GMF Faraday plate 5 and the negative crystal wedge 6 constitute an isolator shared by all channels. The present invention only exemplifies the principle of one channel wavelength passing through the isolator.

[0064] like Figure 8 , the positive crystal wedge 4 and the negative crystal wedge 6 are both birefringent crystals, the inclined planes of the two are parallel, and the vertical plane is S1. The optical axis of the positive crystal wedge 4 is defined as the optical axis A, and the optical axis of the negative crystal wedge 6 is defined as the optical axis B. The optical axes A and B are 45° apart, and are displayed in two-dimensional coordinates as shown in Fig.10 , take the direction of optical axis A as the x-axis.

[0065] like Fig. 9 When the light passes forward, the horizontal collimated light is incident on the wedge 4 and birefringence occurs, generating o light and e light. According to the principle of birefringence, the vibration direction of the o light wave is perpendicular to the plane formed by its propagation direction and the optical axis A, and the vibration direction of the e light wave is horizontal to the plane formed by its propagation direction and the optical axis A. When passing through Faraday 5 and wedge 6, the vibration directions of the o light and the e light are both rotated 45° counterclockwise (from the direction of forward light propagation, that is, from left to right), refer to Fig.10 , the vibration direction of the o light is equivalent to turning counterclockwise from the plane formed by the plane perpendicular to its propagation direction and the optical axis A to the plane formed by the plane perpendicular to its propagation direction and the optical axis B. The vibration direction of the e light is equivalent to turning counterclockwise from the plane formed by the plane parallel to its propagation direction and the optical axis A to the plane parallel to its propagation direction and the optical axis B. At this time, when it is incident on the wedge 6 again, the vibration direction of the o light wave is perpendicular to the plane formed by its propagation direction and the optical axis B, and the vibration direction of the e light wave is horizontal to the plane formed by its propagation direction and the optical axis B. Therefore, the polarization states of the two beams in the two wedges are o→o and e→e respectively. The combination of the two wedges is equivalent to a parallel plate for the forward light. The direction of the forward light remains unchanged after passing through, and is still horizontal. However, after Faraday's rotation, the polarization state rotates 45° counterclockwise, and then rotates 45 degrees clockwise through the half glass slide 7, and maintains the same polarization state as the incident light.

[0066] The half-wave plate 7 is also a birefringent crystal, but its optical axis is in the horizontal direction of forward light transmission. When light propagates along the optical axis inside the crystal, no birefringence occurs. Therefore, the half-wave plate 7 only plays the role of rotating 45°, and no birefringence phenomenon will occur, so it will not affect the optical path difference between the o-ray and the e-ray.

[0067] When the light travels in the reverse direction, the collimated light in the horizontal direction undergoes birefringence when incident on the wedge 6, generating the o-ray and the e-ray. According to the birefringence principle, the vibration direction of the o-ray wave is perpendicular to the plane formed by its propagation direction and the optical axis B, and the vibration direction of the e-ray wave is parallel to the plane formed by its propagation direction and the optical axis B. After passing through the Faraday 5 and the wedge 4, according to the non-reciprocal rotation of light by Faraday, the vibration directions of the o-ray and the e-ray still rotate 45° counterclockwise (viewed from the forward light propagation direction, that is, from left to right). Refer to Fig.10 , the vibration direction of the o-ray is equivalent to rotating counterclockwise from the plane perpendicular to the plane formed by its propagation direction and the optical axis B to the plane perpendicular to the plane formed by its propagation direction and the y-axis, and the y-axis is perpendicular to the optical axis A. Therefore, at this time, the o-ray becomes parallel to the plane formed by its propagation direction and the optical axis A, that is, it becomes the e-ray. And the vibration direction of the e-ray is equivalent to rotating counterclockwise from the plane parallel to the plane formed by its propagation direction and the optical axis B to the plane parallel to the plane where the y-axis is located. Since the y-axis is perpendicular to the optical axis A, therefore, the vibration direction of the e-ray becomes perpendicular to the plane formed by its propagation direction and the optical axis A, becoming the o-ray. Therefore, the polarization states of the two beams of light in the two wedges are o→e and e→o respectively, which is equivalent to passing through a Wollaston prism. Refer to Fig.10 , the reverse light deviates from the original direction after passing through and cannot be coupled into the input optical fiber, achieving the effect of reverse isolation.

[0068] The combination of the two wedges of a common isolator usually uses the same material, the negative crystal LiNbO3, with its refractive index no = 2.286 and ne = 2.203. When the light travels in the forward direction, after the light wave undergoes birefringence through the crystal, the refractive indices of the o-ray and the e-ray inside the crystal are different, the speeds are different, and the paths are also different. Therefore, there is an optical path difference in the propagation of the o-ray and the e-ray. This optical path difference is a large noise for a 100G or higher-speed optical communication system, which will cause large PMD (chromatic dispersion) of the device and weaken the signal fidelity. In the present invention, the wedge 4 uses a positive crystal with ne > no, and the wedge 6 uses a negative crystal with ne < no. Because the main frequency of the light wave only depends on the light source, the frequency remains unchanged when the light propagates in any medium. Assume that the speed of light in air is C and the refractive index is n. When the light undergoes birefringence in the crystal, the speed of the o-ray is vo, the wavelength is λo, the speed of the e-ray is ve, and the wavelength is λe.

[0069] Since the frequency of light \(f = 1 / T\), the speed \(C=\lambda / T=\lambda f\), \(n_e = C / v_e\), \(n_o = C / v_o\), we can get \(C=n_e\times v_e=n_o\times v_o\). So in a negative crystal, when \(n_e < n_o\), \(v_e>v_o\), and the e - light travels faster than the o - light; in a positive crystal, when \(n_e>n_o\), \(v_e < v_o\), and the e - light travels slower than the o - light. Therefore, by selecting materials to control the refractive index of the crystal, using a positive crystal material for the wedge - shaped piece 4 and a negative crystal material for the wedge - shaped piece 6, when the o - light and the e - light pass through the combination of the two wedge - shaped pieces, the optical path difference is 0, and the dispersion PMD of the isolator is 0.

[0070] In summary, the silicon optical isolator engine described in the present invention can transmit optical signals in any polarization state, and can ensure that the light emerging from the silicon optical device remains in the same polarization state after passing through the isolator array. Secondly, after passing through the birefringent crystal, the optical path difference between the o - light and the e - light remains consistent, with small dispersion (almost PMD = 0), which can ensure signal integrity; finally, it has multiple channels for transmitting the same or different wavelength signals, which can improve the system redundancy.

[0071] Embodiment

[0072] The present invention is composed of a mother substrate 1, sub - substrates 10, 20, 30, 40, 80, 90, a silicon optical and waveguide array on the substrate 10, a tapered fiber array on the substrate 20, a first lens array on the substrate 30, a positive - crystal wedge - shaped piece 4, a GMF Faraday sheet 5, a negative - crystal wedge - shaped piece 6, a half - wavelength glass sheet 7 on the substrate 40, a second lens array on the substrate 80, a single - fiber fiber - optic head array and a connector array on the substrate 90. The sub - substrates are fixed on the mother substrate.

[0073] The present invention can be made into a single - channel or multi - channel wavelength module. Here, only a four - channel example is given to illustrate the implementation scheme. The specific implementation scheme is as follows:

[0074] Step 1: As Fig.11 , debug Channel 1: On the optical coupling debugging system, connect one end of the polarization - maintaining fiber to a light source to input a light wave with a wavelength of \(\lambda_1\), connect the fiber of the debugging collimator A01 to a power meter. After adjusting the 8 - degree inclined surface of the fiber head 203 of the first fiber 201 to be flush with the 8 - degree inclined surface of the lens 301, the system is debugged. After debugging the insertion loss to meet the specification requirements and minimizing it, fix the fiber head 203 on the sub - substrate 20 with glue, and fix the lens 301 on the sub - substrate 30 with glue. Temporarily fix the debugging collimator A01 with glue.

[0075] Step 2: As Fig.12 , process one end of the polarization - maintaining fiber on the sub - substrate 20 connected to the light source into a tapered fiber, and fix the tapered end with a fiber head 202 made of a light - transmissive material.

[0076] Step 3: As Fig.12 , use the debugged silicon photonic module (the silicon photonic chip 101 and waveguide 102 of each channel have been debugged and arranged and fixed on the sub-base 10) as the light source. Connect the optical fiber of the debug collimator A01 to the power meter, debug and adjust the position of the optical fiber head 202, so that the light coupling of the silicon photonic module channel 1 enters the tapered optical fiber 201, and is coupled into the power meter through the optical path debugged in the previous step. After debugging until the insertion loss meets the specification and is minimum, fix the optical fiber head 202 on the sub-base 20.

[0077] Step 4: Repeat steps 1 to 3 to adjust the tapered optical fibers and lenses of other channels and fix them on the sub-base. At this point, the components on the sub-bases 10, 20, and 30 have been adjusted and fixed on the base. Remove the adjustment collimator A01.

[0078] Step 5: If Fig.13 , connect the pigtail of polarization-maintaining fiber 901 to the power meter, debug channel one, adjust the octave alignment of lens 801 and fiber head 902, debug the optical path, light is emitted from the silicon photonic chip, coupled into the tapered fiber after passing through the waveguide, then enters lens 801 after being collimated by lens 301, and then converged by lens 801 into fiber 901, and then enters the power meter. After debugging the optical path until the insertion loss meets the specification and is minimized, use glue to fix lens 801 on sub-substrate 80, and use glue to fix fiber head 902 on sub-substrate 90.

[0079] Step 6: Repeat step 5, debug other channels and fix the lens on the sub-base plate 80 at the corresponding channel position, and fix the optical fiber head on the sub-base plate 90 at the corresponding channel position with glue.

[0080] At this time, the components on the sub-substrates 10, 20, 30, 80, 90 have been debugged and fixed, and these sub-substrates are all fixed on the mother substrate.

[0081] Step 7: Preparation of isolator core;

[0082] The isolator core is first debugged from a large piece of isolator, and after passing the test, it is cut into small-sized isolator cores that meet the specifications through a cutting process, and then fixed on the sub-base 40.

[0083] like Fig.14 , a large positive crystal wedge 4, a large GMF Faraday plate 5, and a large negative crystal wedge 6 are glued together with light-transmitting glue, and after high-temperature baking, the test system ( Fig.15 ) Test the insertion loss and isolation parameters, which must meet the specification requirements. After passing the test, the large isolator is cut into multiple small-sized isolator cores that meet the specification requirements using a cutting process, and then cleaned and inspected for appearance before entering the next process.

[0084] refer to Fig.16 , install the isolator core on the substrate 40 and fix it with glue, then install the half glass slide 7 and fix it on the substrate with glue. And use the test system to test the insertion loss and isolation specification parameters again.

[0085] Step 8: Reference Fig.17 , put the debugged isolator core and the sub-base plate 40 into the module as a whole, and after debugging the optical path to minimize the insertion loss, use glue to fix the sub-base plate 40 on the mother base plate 1.

[0086] Step 9: Reference Figure 3 After the entire module is debugged, one end of the optical fiber connected to the power meter on the substrate 90 is passed through a tube to make an optical fiber connector. According to needs, it can be made into MT, LC / PC, LC / APC / , FC / PC, FC / APC and other types of connectors, and then fixed on the substrate 90 for direct plugging and unplugging when used.

[0087] At this point, the silicon optical isolator engine module has been fully debugged and is ready for use after baking, testing, and verification.

Claims

1. Silicon optical isolator engine, characterized by: The invention comprises a mother substrate (1), on which a first sub-substrate (10), a second sub-substrate (20), a third sub-substrate (30), a fourth sub-substrate (40), a fifth sub-substrate (80), and a sixth sub-substrate (90) are arranged in sequence from one end of the mother substrate (1) to the other end; A silicon light and waveguide group is arranged on the first sub-substrate (10); the silicon light and waveguide group is evenly distributed vertically; and each silicon light and waveguide group comprises a silicon chip (101) and a waveguide (102); The second sub-base plate (20) is arrayed with tapered optical fibers (201); The third sub-substrate (30) is provided with an array of first lenses (301); An isolator common to all channels is arranged at one end of the fourth sub-base plate (40); a half-wavelength glass plate (7) is arranged at the other end; the isolator comprises a positive crystal wedge (4), a GMF Faraday plate (5), and a negative crystal wedge (6) which are arranged in sequence in a transverse direction; The fifth sub-substrate (80) is provided with an array of second lenses (801); The sixth sub-base plate (90) is arrayed with single-fiber optical fiber heads (902); the single-fiber optical fiber heads (902) are connected to polarization-maintaining optical fibers (901); The silicon optical waveguide group, the tapered optical fiber (201), the first lens (301), the second lens (801), and the single-fiber optical fiber head (902) correspond one to one.

2. The silicon optical isolator engine of claim 1, wherein: The positive crystal wedge (4) and the negative crystal wedge (6) are both made of birefringent crystals and both have an inclined surface and a vertical surface; the inclined surfaces of the two are parallel; The vertical plane is S1; the optical axis of the positive crystal wedge (4) is the optical axis A, the optical axis of the negative crystal wedge (6) is the optical axis B, and the optical axes A and B form an angle of 45°.

3. The silicon optical isolator engine of claim 2, wherein: The half-wavelength glass slide (7) adopts a birefringent crystal, and the optical axis of the half-wavelength glass slide (7) is in the horizontal direction of the forward light transmission.

4. The silicon optical isolator engine of claim 3, wherein: One end of the polarization-maintaining optical fiber (901) is connected to an optical fiber connector, and the optical fiber connector is an MT, FC / PC, FC / APC, LC / PC, LC / APC or other type of optical fiber connector.

5. The silicon optical isolator engine of claim 4, wherein: The tapered optical fiber (201) is provided with a first fixed optical fiber head (202) at one end and a second fixed optical fiber head (203) at the other end; the second fixed optical fiber head (203) has an inclined 8-degree surface that is flush with the inclined 8-degree surface of the first lens (301).

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