CN110646881A - A three-dimensional optical waveguide transition access device and preparation method thereof - Google Patents

Abstract

The invention discloses a three-dimensional optical waveguide transition access device and a preparation method thereof. The three-dimensional optical waveguide transition access device comprises: a substrate, a transparent frame fixed on the substrate, a cladding layer in the transparent frame and a A waveguide core layer disposed in the cladding for light propagation and conversion of light mode spots. The waveguide core layer is composed of two layers of "S"-shaped curved conical waveguide arrays arranged in parallel, the shape of which is symmetrical up and down and arranged at intervals. The wide end of the "S"-shaped curved tapered waveguide array is connected with the optical fiber array, and the narrow end is aligned with the photonic integrated waveguide array. The invention can realize the efficient coupling of the closely arranged double-layer waveguide array and the standard optical fiber array, and effectively solve the coupling problem of the three-dimensional interlayer waveguide. In addition, the preparation method of the present invention has the advantages of simple process, easy realization, strong controllability and the like, and greatly reduces the production cost.

Description

A three-dimensional optical waveguide transition access device and preparation method thereof

technical field

The invention relates to the technical field of integrated photonic devices, in particular, to a three-dimensional optical waveguide transition access device and a preparation method thereof.

Background technique

With the increasing requirements of optical interconnection technology for speed and integration density, traditional integrated photonic chips can no longer meet the requirements due to the limitations of on-chip space, loss, and manufacturing tolerances. In recent years, three-dimensional integration technology has gradually attracted people's attention. Multilayer structures exploiting the nature of three-dimensional integration and multifunctional materials can address the development limitations of traditional integrated photonic platforms, and additional optical device layers can provide higher density integration, lower losses, better device performance, and higher manufacturing tolerances. However, while the multi-layer structure brings the above advantages, it also faces a huge problem, that is, the coupling package of the integrated photonic chip.

The distance between the layers of the multi-layer integrated photonic chip is several to tens of microns, while the cladding diameter of a standard single-mode fiber is about 125 microns. Coupling of components presents significant challenges. Therefore, a transition device is needed to solve the problem of coupling between the three-dimensional multilayer waveguide and the optical fiber array.

At present, the conical mode spot converter is mostly used as a transition device to realize the coupling between the photonic integrated chip and the optical fiber. The most common is the two-dimensional conical mode-spot converter, which has a relatively simple structure and only changes in size in the horizontal direction. However, due to the limitation in the vertical direction, the mode field distribution is generally flat and elliptical, which greatly reduces the coupling efficiency with the fiber. The three-dimensional tapered mode spot converter can vary its dimensions in both the horizontal and vertical directions, thereby improving matching to the fiber mode field. However, its preparation process is relatively complicated, and it can only change the size in the vertical direction, and cannot realize the shape change such as bending in the vertical direction. This three-dimensional mode spot converter can only realize the coupling between the single-layer photonic integrated waveguide and the optical fiber. The limitation of the larger cladding diameter of the fiber to the coupling of multiple layers of closely spaced waveguides to the fiber components cannot be overcome.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the purpose of the present invention is to provide a three-dimensional optical waveguide transition access device, which overcomes the limitation of the larger cladding diameter of the optical fiber and realizes the coupling of the closely arranged three-dimensional multilayer waveguide array and the standard optical fiber array. .

Technical scheme: in order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme:

The three-dimensional optical waveguide transition access device of the present invention includes a substrate, a transparent frame fixed on the substrate, a cladding layer in the frame and a cladding layer for light propagation and conversion of optical modes. Spotted waveguide core layer. The waveguide core layer is composed of two layers of "S"-shaped curved tapered waveguide arrays arranged in parallel. The "S"-shaped curved tapered waveguide includes a wide end and a narrow end, and is tapered gradually from the narrow end to the wide end, which not only realizes size changes in the horizontal and vertical directions, but also bends in the vertical direction. The wide end of the "S"-shaped curved tapered waveguide array is connected with the optical fiber, and the narrow end is aligned with the photonic integrated waveguide.

The present invention can also adopt the following technical measures to further optimize the three-dimensional optical waveguide transition access device:

Optionally, the two end faces of the device may be vertical, or may be ground into inclined end faces with a certain inclination angle.

Optionally, the cross sections of the wide end and the narrow end of the "S"-shaped curved tapered waveguide are both circular, the diameter of the narrow end is D1, and the diameter of the wide end is D2.

Optionally, the distance between two adjacent "S"-shaped curved tapered waveguides in each layer is d, and the vertical distance between the two "S"-shaped curved tapered waveguide arrays is h.

Optionally, the positions of the upper and lower layers of the "S"-shaped curved tapered waveguides may be aligned, or may be staggered by a certain distance g in the horizontal direction.

Optionally, the substrate is made of materials such as silicon, silicon dioxide, silicon nitride or glass.

Optionally, the transparent frame is made of materials such as acrylic, glass or epoxy polymer.

Optionally, both the cladding layer and the waveguide core layer are made of UV-curable polymer materials, such as silicate-based resins, modified acrylates, epoxy resins, organic-inorganic hybrid resins, and the like.

Optionally, the viscosity of the cladding material is v1, the refractive index is n1, the viscosity of the core material is v2, and the refractive index is n2, and v1<v2, n1<n2.

The present invention also provides a method for preparing a three-dimensional optical waveguide transition access device, comprising the following steps:

Step 1: Take a substrate and fix the transparent frame on the substrate with glue.

Step 2: Use a dropper to spread the liquid cladding material evenly in the frame to fill it up.

Step 3: a) Fix the syringe of the dispenser on the desktop control robotic arm.

b) Add the liquid core material to the syringe of the dispenser.

c) Insert the needle into the liquid cladding material, and set the position and height, movement trajectory and movement speed of the needle insertion by controlling the robotic arm.

d) A certain pressure is applied to the liquid core layer material in the needle cylinder, so that the needle head disperses the liquid core layer material into the liquid cladding layer material according to the set speed and trajectory.

e) Pull the needle out of the liquid cladding material.

f) Repeat steps b)-e).

Step 4: Curing under UV light source, then aging at 50°C for 12 hours;

Step 5: Cut, grind and polish both ends of the three-dimensional optical waveguide transition access device.

Optionally, the shape of the waveguide is determined by the movement trajectory of the needle, and the diameter of the waveguide is controlled by the pressure, the inner diameter of the needle, and the movement speed of the needle.

Optionally, when fabricating the waveguide core layer, the beginning part of the narrow end and the ending part of the wide end of the "S"-shaped curved tapered waveguide contain a section of uniform structure for subsequent cutting and grinding processes.

Beneficial effect: Compared with the prior art, the present invention has the following advantages:

1. Realize the coupling between the three-dimensional multilayer waveguide and the fiber array. The present invention provides a three-dimensional optical waveguide transition access device. Compared with the common three-dimensional tapered mode spot conversion device, it not only realizes the change in size, but also bends in the vertical direction, which can convert the densely arranged multilayer waveguides into The interlayer spacing (a few microns) is expanded to several hundreds of microns to overcome the limitation of the fiber cladding diameter and realize the efficient coupling of the three-dimensional multilayer waveguide array and the fiber array.

2. The process is simple and the cost is low. The present invention is a preparation method of a three-dimensional optical waveguide transition access device, which utilizes a novel needle tube dispersion method to manufacture a three-dimensional optical waveguide transition access device, which is different from the traditional photolithography method, does not require a photomask, and has a simple process that takes only a few minutes. The production can be completed, which greatly reduces the production cost.

3. The adjustment method is simple and efficient, and the controllability is high. In the preparation method of the three-dimensional optical waveguide transition access device of the present invention, the shape and size of the waveguide can be controlled only by adjusting parameters such as needle movement trajectory, movement speed, and pressure, thereby obtaining a device with better performance.

Description of drawings

1 is a schematic diagram of the basic structure of a three-dimensional optical waveguide transition access device provided by an embodiment of the present invention;

Fig. 2 is a partial enlarged view of the "S"-shaped curved tapered waveguide;

3 is a front view of the three-dimensional optical waveguide transition access device of the present invention;

4 is a rear view of the three-dimensional optical waveguide transition access device of the present invention;

Fig. 5-Fig. 9 are the preparation steps of the three-dimensional optical waveguide transition access device;

There are: substrate 1, transparent frame 2, cladding 3, "S"-shaped curved tapered waveguide 4.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments.

As shown in FIG. 1, the three-dimensional optical waveguide transition access device of the present invention includes a substrate 1, a fixed transparent frame 2 on the substrate, a cladding layer 3 and a waveguide core layer in the transparent frame (not shown in the figure). marked). The waveguide core layer is composed of two parallel arrays of "S"-shaped curved tapered waveguides 4, which are symmetrical in shape up and down and arranged at intervals. As shown in FIG. 2 , the “S”-shaped curved tapered waveguide 4 includes a wide end and a narrow end, and the cross-sectional shapes of the wide end and the narrow end are both circular, tapered gradually from the narrow end to the wide end, and bent in the vertical direction. The wide end has a diameter of 10 μm and is aligned with the optical fiber, and the narrow end has a diameter of 3 μm and is connected to the photonic integrated waveguide. Both ends of the device are vertical, and the end surface structure is shown in Figures 3 and 4. The "S"-shaped curved tapered waveguide 4 array has a layer spacing of 21um between the upper and lower layers at the narrow end, and the layer spacing between the upper and lower layers at the wide end is 250μm. The lateral spacing of adjacent "S"-shaped curved tapered waveguides 4 in each layer is 127 μm.

The substrate 1 is made of glass, and the transparent frame 2 is made of acrylic. The cladding layer 3 and the waveguide core layer are both made of UV-curable optical glue from NORLAND Corporation of the United States. The material of the cladding 3 is NOA76, has a viscosity of 4,000 mPa·s, and a refractive index of 1.51. The model of the core layer material is NOA68T, the viscosity is 25,000 mPa·s, and the refractive index is 1.54.

The preparation steps of the three-dimensional optical waveguide transition access device of the present embodiment are as follows:

Step 1: Take a glass substrate with a size of 500mm×150mm as the substrate, fix the transparent frame on the substrate with glue, and form a groove with a length of 300mm, a width of 100mm and a height of 1mm with the substrate, as shown in Figure 5.

Step 2: Use a dropper to evenly disperse the liquid cladding material in the grooves in the frame and fill it up, as shown in Figure 6.

Step 3: a) Install a needle with an inner diameter of 20 μm on the syringe barrel of the dispensing machine, and fix the syringe barrel of the dispensing machine on the desktop control robotic arm;

b) Add the liquid core material to the syringe of the dispenser.

c) Insert the needle into the liquid cladding material, and set the position and height, movement trajectory and movement speed of the needle insertion by controlling the robotic arm.

d) Apply a pressure of 150kPa to the liquid core layer material in the needle cylinder, so that the needle head disperses the liquid core layer material into the liquid cladding material according to the set trajectory. During the dispersion process, adjust the needle head moving speed gradually from 300mm/s. Change to 20mm/s, the "S"-shaped curved tapered waveguide can be obtained;

e) pulling the needle out of the liquid cladding material;

f) Repeat steps b)-e) to obtain a two-layer "S"-shaped curved tapered waveguide array, as shown in Figure 7 and Figure 8;

Step 4: Curing for 3 minutes under a UV light source with a wavelength of 365nm and a power of 8W, and then aging at a temperature of 50°C for 12 hours, as shown in Figure 9.

Step 5: Cut, grind and polish both ends of the three-dimensional optical waveguide transition access device.

The present invention is not limited to the above-mentioned embodiments. For those skilled in the art, several improvements can be made without departing from the principles of the present invention, and these improvements are also regarded as within the protection scope of the present invention. Contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims (10)

1. A three-dimensional optical waveguide transition access device, comprising: a substrate, a transparent frame fixed on the substrate, a cladding layer in the transparent frame, and a waveguide arranged in the cladding layer for light propagation and conversion of light mode spots The core layer is characterized in that: the waveguide core layer is composed of two layers of "S"-shaped curved tapered waveguide arrays arranged in parallel, the shape of which is symmetrical up and down and arranged at intervals; the "S"-shaped curved tapered waveguide includes a wide end and a narrow end, It is tapered from the narrow end to the wide end, and is bent in the vertical direction, the wide end is connected with the optical fiber, and the narrow end is aligned with the photonic integrated waveguide. 2 . The three-dimensional optical waveguide transition access device according to claim 1 , wherein the cross-sections of the wide end and the narrow end of the “S”-shaped curved tapered waveguide are circular; the two ends of the device are vertical, Alternatively, it is ground into an inclined end face with a certain inclination angle, and the inclination angle is inclined at 8°. 3 . The three-dimensional optical waveguide transition access device according to claim 1 , wherein the upper and lower layers of the “S”-shaped curved tapered waveguides are aligned in position, or staggered by a distance g in the horizontal direction. 4 . 4 . The three-dimensional optical waveguide transition access device according to claim 1 , wherein the substrate is made of silicon, silicon dioxide, silicon nitride or glass material. 5 . 5 . The three-dimensional optical waveguide transition access device according to claim 1 , wherein the transparent frame is made of acrylic, glass or epoxy resin polymer material. 6 . 6 . The three-dimensional optical waveguide transition access device according to claim 1 , wherein the cladding layer and the waveguide core layer are both made of UV-curable polymer materials, and the UV-curable polymer materials comprise silicate-based Resins, modified acrylates, epoxy resins and organic-inorganic hybrid resins. 7. The three-dimensional optical waveguide transition access device according to claim 6, wherein the viscosity of the cladding material is v1, the refractive index is n1, the viscosity of the waveguide core material is v2, the refractive index is n2, and v1<v2, n1<n2. 8. A method for preparing a three-dimensional optical waveguide transition access device, wherein the steps are: Step 1: Take a substrate and fix the transparent frame on the substrate with glue; Step 2: Use a dropper to evenly disperse the liquid cladding material in the frame and fill it up; Step 3: (a) Fix the syringe of the dispenser on the desktop control robotic arm; (b) adding the liquid core material to the syringe of the dispenser; (c) inserting the needle into the liquid cladding material, and setting the position and height, movement trajectory and movement speed of the needle insertion by controlling the robotic arm; (d) applying a certain pressure to the liquid core material in the needle cylinder, so that the needle disperses the liquid core material into the liquid cladding material according to the set speed and trajectory; (e) pulling the needle out of the liquid cladding material; (f) Repeat steps (b)-(e); Step 4: Curing under UV light source, then aging at 50°C for 12 hours; Step 5: Cut, grind and polish both ends of the three-dimensional optical waveguide transition access device. 9 . The method for preparing a three-dimensional optical waveguide transition access device according to claim 8 , wherein the shape of the waveguide is determined by the movement trajectory of the needle, and the diameter of the waveguide is controlled by the pressure, the inner diameter of the needle, and the moving speed of the needle. Smaller, the smaller the inner diameter of the needle, and the faster the needle moves, the smaller the diameter of the waveguide. 10 . The method for preparing a three-dimensional optical waveguide transition access device according to claim 8 , wherein when fabricating the waveguide core layer, the “S”-shaped curved tapered waveguide starts at the narrow end and ends at the wide end. 11 . Contains a section of uniform structure for subsequent cutting and grinding.

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