CN116679388A - Optical fiber array structure coupled with silicon optical integrated chip - Google Patents

Abstract

The invention discloses an optical fiber array structure coupled with a silicon optical integrated chip, which comprises the following components: the device comprises a waveguide passive chip and a light conduction structure, wherein a V-shaped groove for fixing the light conduction structure is etched on the waveguide passive chip, and the light conduction structure is an optical fiber or an optical fiber ribbon; the size of the optical mode field of the end of the waveguide passive chip coupled with the optical conduction structure is matched with that of a single-mode optical fiber, and the size of the optical mode field of the end coupled with the silicon optical integrated chip is matched with that of a spot-size converter in the silicon optical integrated chip. The waveguide passive chip realizes the mode spot conversion function, the size of the mode field of the optical coupling structure in the silicon optical integrated chip is only required to be matched with the waveguide passive chip, the influence of the mode field of the single-mode optical fiber is avoided, the design and manufacturing difficulty of the optical coupling structure in the silicon optical integrated chip can be reduced, and the optical coupling efficiency is improved.

Description

A Fiber Array Structure Coupled with Silicon Photonics Integrated Chip

technical field

The invention relates to the technical field of optical communication, in particular to an optical fiber array structure coupled with a silicon optical integrated chip.

Background technique

Silicon-based optoelectronic integrated chips based on silicon photonics technology can integrate multiple high-speed modulators, high-speed detectors, beam splitters/combiners, and wavelength division multiplexing/demultiplexing devices, which can meet large-capacity communications and are large-bandwidth , Low power consumption, low cost and one of the ideal solutions for high-speed optical interconnection.

Silicon photonics integrated chips need to be optically coupled with optical fiber arrays in many usage scenarios, so as to realize the import and export of optical signals. The optical coupling effect between the two has a significant impact on optical communication systems. The size of the optical waveguide in the silicon photonics integrated chip is usually on the order of hundreds of nanometers in width and height, while the mode field size of the single-mode fiber is on the order of 8-10um. This mismatch in size will lead to a large optical waveguide coupling loss. Although the optical mode field can be expanded by designing the optical mode spot converter structure on the silicon photonics integrated chip, thereby improving the coupling efficiency, it is still difficult to expand to the order of 8-10um, and often requires the use of cantilever beams The structure etches away the silicon on the substrate near the spot conversion structure, and the process is complicated and not conducive to the development of the back-end process of the silicon photonics integrated chip.

Contents of the invention

In order to solve the above technical problems, the present invention provides an optical fiber array structure coupled with a silicon optical integrated chip. In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is presented below. This summary is not an overview, nor is it intended to identify key/critical elements or delineate the scope of these embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

The present invention adopts following technical scheme:

An optical fiber array structure coupled with a silicon photonics integrated chip is provided, including: a waveguide passive chip and a light transmission structure, and a V-shaped groove for fixing the light transmission structure is etched on the waveguide passive chip;

The size of the optical mode field at the end of the waveguide passive chip coupled with the light-conducting structure matches the size of the optical mode field of the single-mode fiber, and the size of the optical mode field at the end coupled with the silicon-optical integrated chip is the same as that in the silicon-optical integrated chip. The optical mode field of the mode spot converter is matched;

The light conducting structure is an optical fiber or an optical fiber ribbon.

Further, one or more of a beam combiner, a beam splitter, a wavelength division multiplexer, and a wave division multiplexer are arranged on the waveguide passive chip.

Further, the waveguide passive chip is a passive chip based on silicon nitride waveguide/silicon oxynitride waveguide/silicon dioxide waveguide/thick silicon waveguide.

Further, the number of the V-shaped grooves is the same as the number of optical fibers in the light transmission structure.

Further, the optical fiber array structure coupled with the silicon optical integrated chip also includes: a cover plate; the coupling end of the optical fiber in the light transmission structure is arranged above the V-shaped groove, and the cover plate presses Hold the position of the bare fiber in the front section of the optical fiber, and use glue to cure and bond.

Further, the waveguide passive chip is also provided with a second coupling structure, an optical waveguide, and a third coupling structure; the second coupling structure is used for optical coupling with the first coupling structure on the silicon-optical integrated chip, so The third coupling structure is used for optical coupling with the light transmission structure, and the optical waveguide connects the second coupling structure and the third coupling structure.

The beneficial effects brought by the present invention:

1. The waveguide passive chip realizes the mode spot conversion function. The size of the mode field of the optical coupling structure in the silicon photonic integrated chip only needs to be matched with the waveguide passive chip. It is not affected by the mode field of the single-mode fiber and can reduce silicon Difficulty in the design and manufacture of optical coupling structures in optical integrated chips to improve optical coupling efficiency;

2. The optical beam splitting structure can be made in the waveguide passive chip, so that when using a high-power external laser, there is no need to worry about the optical power of the silicon optical waveguide. It only needs to split the beam through the optical beam splitting structure, and then multiple Luguang can be imported into the silicon photonics integrated chip;

3. In the scene where wavelength division multiplexing/demultiplexing is required, the wavelength division multiplexing/demultiplexing function is integrated in the waveguide passive chip, which does not need to be fabricated in the silicon-optical integrated chip, which can avoid silicon-based optical The performance of waveguide-type wavelength division multiplexing/demultiplexing devices is affected by temperature, resulting in failure to work normally.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 takes DR8PIC as an example, a schematic structural diagram of a silicon photonics integrated chip coupled with an optical fiber array structure of the present invention;

FIG. 2 is a schematic diagram of the coupling of the silicon photonics integrated chip and the optical fiber array structure of the present invention, taking 2XFR4PIC as an example.

Detailed ways

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be clear that the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

As shown in FIGS. 1-2 , in some illustrative embodiments, the present invention provides an optical fiber array structure coupled with a silicon optical integrated chip, including: a waveguide passive chip 1 , a cover plate 2 and a light transmission structure 3 .

The waveguide passive chip 1 is used as the substrate of the light transmission structure 3, on which a V-shaped groove 101 is etched for fixing the light transmission structure 3, wherein the light transmission structure 3 is an optical fiber or an optical fiber ribbon, and the optical fiber ribbon is composed of 4 to 24 A thin flat ribbon cured by UV light arranged in parallel.

The waveguide passive chip 1 of this embodiment can also function as a mode-spot converter. Specifically, the size of the optical mode field at one end of the waveguide passive chip 1 coupled with the light-conducting structure 3 is the same as that of the single-mode optical fiber. Matching, the size of the optical mode field at the end coupled with the silicon optical integrated chip 4 matches the optical mode field of the mode spot converter in the silicon optical integrated chip 4 .

The number of V-shaped grooves 101 is the same as the number of optical fibers in the light transmission structure 3 . The size design of the V-groove 101 needs to satisfy that after the optical fiber is put in, the center of the mode field of the coupled optical waveguide in the waveguide passive chip 1 basically coincides with the center of the mode field of the optical fiber.

The coupling end of the optical fiber in the light transmission structure 3 is set above the V-shaped groove 101, and the cover plate 2 presses the bare fiber position of the front section of the optical fiber, and is cured and bonded with glue to ensure structural stability.

The waveguide passive chip 1 realizes the function of mode spot conversion, so that the size of the mode field of the optical coupling structure in the silicon photonic integrated chip 4 only needs to be matched with the waveguide passive chip 1, and is not affected by the mode field of the single-mode fiber. The difficulty of designing and manufacturing the optical coupling structure in the silicon photonics integrated chip 4 can be reduced, and the optical coupling efficiency can be improved.

In some illustrative embodiments, the waveguide passive chip 1 may be a passive chip based on a silicon nitride waveguide/silicon oxynitride waveguide/silicon dioxide waveguide/thick silicon waveguide. Thick silicon waveguides refer to silicon waveguides with a thickness of at least 3um.

In some illustrative embodiments, the waveguide passive chip 1 is further provided with a second coupling structure 102, an optical waveguide 103, and a third coupling structure 104, and the second coupling structure 102 is used to communicate with the first The coupling structure 401 performs optical coupling, the third coupling structure 104 is used for optical coupling with the light transmission structure 3 , and the optical waveguide 103 connects the second coupling structure 102 and the third coupling structure 104 .

Because silicon materials are affected by two-photon absorption and free carrier absorption effects, it is difficult for silicon photonic integrated chips to withstand large optical power, so it is impossible to use high-power external lasers to introduce light into silicon photonic integrated chips through optical fibers. , but only a larger number of low-power lasers and more channel fiber arrays can be used, which not only increases the material cost, but also increases the size of the optical engine/module. At the same time, due to the large thermo-optic coefficient of silicon materials, the performance of some silicon-based passive waveguide devices (such as silicon-based wavelength division multiplexing/demultiplexing, etc.) is easily affected by temperature, resulting in the use of silicon optical integrated chips restricted. Adding a thermal control structure to some passive waveguide devices in silicon photonics integrated chips can solve this problem to a certain extent, but it increases the complexity of chip use and power consumption.

In order to solve the above technical problems, in this embodiment, one or more of beam combiners, beam splitters, wavelength division multiplexers, and wave division multiplexers are provided on the waveguide passive chip 1 .

The optical beam splitting structure in the waveguide passive chip 1 realizes that a high-power external laser can be used for beam splitting through the fiber array structure, and then multiple paths of light are introduced into the silicon optical integrated chip 4 without worrying about the optical power of the silicon optical waveguide Accept problems. At the same time, the wavelength division multiplexing/demultiplexing function is integrated in the waveguide passive chip 1, which can avoid the situation that the performance of the silicon-based optical waveguide type wavelength division multiplexing/demultiplexing device is affected by the temperature and cannot work normally. .

The core spacing in the fiber array is generally 250um or 127um. The existence of the fiber array spacing makes the chip further limited by the diameter of the fiber itself, that is, the size of the multi-channel highly integrated silicon photonic integrated chip is restricted by the fiber array core spacing. The waveguide passive chip of this embodiment has the fan-out function of the optical interface, so that the distance between each optical port in the multi-channel highly integrated silicon optical integrated chip is no longer restricted by the distance between the cores of the optical fiber array.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (6)

1. An optical fiber array structure coupled with a silicon optical integrated chip, characterized in that it includes: a waveguide passive chip and a light-conducting structure, and the waveguide passive chip is etched with a V for fixing the light-conducting structure Groove; The size of the optical mode field at the end of the waveguide passive chip coupled with the light-conducting structure matches the size of the optical mode field of the single-mode fiber, and the size of the optical mode field at the end coupled with the silicon-optical integrated chip is the same as that in the silicon-optical integrated chip. The optical mode field of the mode spot converter is matched; The light conducting structure is an optical fiber or an optical fiber ribbon. 2. A fiber array structure coupled with a silicon photonics integrated chip according to claim 1, wherein a beam combiner, a beam splitter, and a wavelength division multiplexer are arranged on the waveguide passive chip , one or more of wave division multiplexers. 3. A fiber array structure coupled with a silicon photonics integrated chip according to claim 2, wherein the waveguide passive chip is based on silicon nitride waveguide/silicon oxide waveguide/silicon dioxide waveguide/thick Passive chips with silicon waveguides. 4 . The optical fiber array structure coupled with a silicon photonics integrated chip according to claim 3 , wherein the number of the V-shaped grooves is the same as the number of optical fibers in the light transmission structure. 5. A fiber array structure coupled with a silicon photonics integrated chip according to claim 4, further comprising: a cover plate; the coupling end of the optical fiber in the light transmission structure is arranged on the V-groove Above, the cover plate presses the bare fiber position of the front section of the optical fiber, and is cured and bonded with glue. 6. A fiber array structure coupled with a silicon photonics integrated chip according to claim 5, wherein a second coupling structure, an optical waveguide and a third coupling structure are also arranged on the waveguide passive chip; The second coupling structure is used for optical coupling with the first coupling structure on the silicon optical integrated chip, the third coupling structure is used for optical coupling with the light transmission structure, and the optical waveguide is connected to the second a coupling structure and the third coupling structure.