An optical module

Abstract

The application discloses an optical module, which comprises a light generator, a collimating mirror, a focusing mirror, a light path deflection element, a silicon optical chip and a box body for packaging the light generator; the light generator, the collimating mirror, the focusing mirror and the light path deflection element are arranged in sequence on the silicon optical chip along a propagation path of light; the light path deflection element is used for reflecting light emitted by the focusing mirror to a preset direction; the box body forms a containing space with an opening facing the silicon optical chip; the silicon optical chip closes the opening of the containing space; the light generator and the collimating mirror are located in the containing space; and the focusing mirror and the light path deflection element are located outside the containing space. The optical module can reduce the total volume of the light source.

Description

Technical Field

[0001] This invention relates to the field of silicon-based photonic device technology, and more specifically to an optical module. Background Technology

[0002] With the continuous development of optical communication technology, optical modules are moving towards smaller size, higher integration, and lower cost.

[0003] Silicon photonics is a discipline that focuses on the structural design and fabrication of silicon-based photonic devices and their practical applications in optical communication, optical computing, and other fields. Silicon-based photonic devices include silicon-based light-emitting devices, optical waveguides, silicon-based optoelectronic integration, and silicon-based optical interconnects. Compared to traditional III-V group semiconductor optoelectronic materials, silicon-based optoelectronic chips offer advantages in smaller size and lower cost. Therefore, in current technology, optical waveguides are fabricated on top of silicon-based chips for optical transmission. Integrating integrated circuit chips and optical chips onto the same silicon-based chip is generally referred to as a silicon photonic chip or optoelectronic integrated chip. Silicon photonic chips can perform both electrical signal processing functions, such as electronic amplifiers and digital signal processors, and optical transmission, enabling functions such as optical signal filtering, beam splitting, and modulation. This achieves miniaturization, integration, and low cost of optical modules, meeting the high port density and low-cost requirements of data centers, and has broad application prospects.

[0004] However, silicon, as an indirect bandgap semiconductor, has a much lower luminous efficiency than III-V group semiconductor optoelectronic materials, making it unsuitable as a light source. Therefore, external light sources are generally used to provide light for silicon photonic chips. However, existing external light sources typically suffer from large size, which in turn affects the miniaturization of optical modules. Summary of the Invention

[0005] In view of this, embodiments of the present invention aim to provide an optical module that can reduce the size of the light source used therein.

[0006] To achieve the above objectives, the technical solution of this invention is implemented as follows:

[0007] This invention provides an optical module comprising a light generator, a collimating lens, a focusing lens, an optical path deflection element, a silicon photonics chip, and a housing for encapsulating the light generator. The light generator, collimating lens, focusing lens, and optical path deflection element are arranged sequentially on the silicon photonics chip along the propagation path of the light. The optical path deflection element is used to reflect the light emitted by the focusing lens to a preset direction.

[0008] The housing forms an accommodating space with an opening facing the silicon photonic chip; the silicon photonic chip closes the opening of the accommodating space, the light generator and collimating lens are located inside the accommodating space, and the focusing lens and optical path deflection element are located outside the accommodating space.

[0009] In the above scheme, the inner and outer walls of the side plate of the box separating the collimating lens and the focusing lens are coated with an anti-reflective coating.

[0010] In the above scheme, the side plate of the box separating the collimating lens and the focusing lens is a flat plate made of silicon.

[0011] In the above scheme, the optical module further includes an isolator, which is disposed on the silicon photonic chip between the collimating lens and the focusing lens and is located within the accommodating space.

[0012] In the above scheme, the housing and the silicon photonic chip are connected by welding and sealing, and the contact surface of the side plate of the housing and the silicon photonic chip is plated with a metal coating to increase the welding and sealing performance.

[0013] In the above scheme, the solder used for welding the silicon photonic chip to the side plate of the housing is gold-tin solder, and the metal plating layer is a gold plating layer.

[0014] In the above scheme, the focusing lens and the optical path deflection element are bonded and fixed together.

[0015] In the above scheme, the optical module also includes a heat sink disposed on the upper surface of the silicon photonic chip, and the light generator, collimating lens and isolator are all disposed on the heat sink.

[0016] In the above scheme, the heat sink is plated with multiple metal wires, and the metal wires are electrically connected to the light generator.

[0017] In the above scheme, the silicon photonic chip is configured with a waveguide and a grating coupler disposed at one end of the waveguide. The grating coupler is used to receive light reflected from the optical path deflection element.

[0018] The optical module of this invention encapsulates the light generator and collimating lens within a housing, eliminating the need for a standard coaxial cap and reducing the overall volume of the light source. Furthermore, the housing offers better sealing performance, effectively isolating external moisture and extending the lifespan of the light generator. By reflecting light to a preset direction through an optical path deflection element, the light signal is not transmitted via optical fiber, further reducing the overall volume of the light source. By sealing only the light generator and collimating lens, eliminating the need for overall encapsulation, the overall volume of the light source is further reduced, and optical path adjustment is made easier.

[0019] Other beneficial effects of the embodiments of the present invention will be further explained in conjunction with specific technical solutions in the specific implementation methods. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly described below. It should be understood that the drawings described below are only a part of the drawings in the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of an optical module according to an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A top view diagram (excluding the box).

[0023] Explanation of reference numerals in the attached figures:

[0024] 11 Light generator; 12 Collimating lens; 13 Isolator; 14 C lens; 151 First prism; 152 Second prism; 21 Housing; 22 Welding area; 31 Silicon photonic chip; 32 Heat sink. Detailed Implementation

[0025] To address the problems in the prior art, embodiments of the present invention provide an optical module, which includes a light generator, a collimating lens, a focusing lens, an optical path deflection element, a silicon photonics chip, and a housing for encapsulating the light generator; the light generator, collimating lens, focusing lens, and optical path deflection element are arranged sequentially on the silicon photonics chip along the propagation path of the light, and the optical path deflection element is used to reflect the light emitted by the focusing lens to a preset direction;

[0026] The housing forms an accommodating space with an opening facing the silicon photonic chip; the silicon photonic chip closes the opening of the accommodating space, the light generator and collimating lens are located inside the accommodating space, and the focusing lens and optical path deflection element are located outside the accommodating space.

[0027] An optical module according to an embodiment of the present invention encapsulates a light generator and a collimating lens within a housing, eliminating the need for a universal coaxial tube cap (TO, Transistor Outline) and reducing the overall volume of the light source. Furthermore, the housing offers better sealing performance, effectively isolating external moisture and extending the lifespan of the light generator. By reflecting light to a preset direction through an optical path deflection element, the light signal can be transmitted via optical fiber, further reducing the overall volume of the light source. By sealing only the light generator and collimating lens, eliminating the need for overall encapsulation, the overall volume of the light source is further reduced, and optical path adjustment is made easier.

[0028] It should be noted that existing light source packaging generally uses coaxial cap packaging. The coaxial cap in this packaging is typically of a standard size, resulting in a relatively large volume to accommodate a wider range of light generators. Furthermore, in existing coaxial cap packages, one end of the light source is a connector pin, while the other end is an optical fiber for outputting the light signal, further increasing the size. In contrast, this invention not only improves the coaxial cap by creating a smaller, more adaptable housing for light generators and replaces the optical fiber with an optical path deflection element, but also creatively places the focusing lens and optical path deflection element outside the package, further reducing the overall size of the light source and facilitating optical path adjustment.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the embodiments described below are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on these embodiments without creative effort are within the scope of protection of the present invention.

[0030] Example

[0031] This embodiment provides an optical module, such as Figure 1 , Figure 2 As shown, the optical module includes a light generator 11, a collimating lens 12, a focusing lens, an optical path deflection element, a silicon photonics chip 31, and a housing 21 for encapsulating the light generator 11. The light generator 11, the collimating lens 12, the focusing lens, and the optical path deflection element are arranged sequentially on the silicon photonics chip along the propagation path of the light. The optical path deflection element is used to reflect the light emitted by the focusing lens to a preset direction.

[0032] The housing 21 forms an accommodating space with an opening facing the silicon photonic chip 31; the silicon photonic chip 31 closes the opening of the accommodating space, the light generator 11 and the collimating lens 12 are located inside the accommodating space, and the focusing lens and the optical path deflection element are located outside the accommodating space.

[0033] Here, exemplarily, the light generator 11 can be a laser chip, used to emit corresponding light according to a received control signal, where the control signal is an electrical signal. Here, exemplarily, the collimating lens 12 is used to convert diverging light emitted from the light source into collimated light, used in the beam delivery system to maintain the collimation of the beam between the laser chip and the focusing lens. The focusing lens is used to converge parallel light rays. The optical path deflection element is used to reflect the light emitted from the focusing lens to a preset direction to adapt to the needs of the optical module; the preset direction can be the direction of entry into the optical waveguide. In the optical module, the position of the optical waveguide can be set as needed. Exemplarily, the optical path deflection element can be a prism. The laser chip, collimating lens 12, focusing lens, and optical path deflection element described above are all general optical components and will not be described in detail.

[0034] Here, the focusing lens and the optical path deflection element are located outside the accommodating space, which can further reduce the volume of the light source. Moreover, since the focusing lens and the optical path deflection element are located outside the accommodating space, there is more room to adjust the direction of the optical path, which makes it easier to adjust the optical path.

[0035] Since the collimating lens 12 within the sealed space needs to transmit light to the focusing lens, the light transmittance of the side plate of the housing 21 separating the collimating lens 12 and the focusing lens needs to exceed a preset value. This preset value depends on the specific light requirements of the optical module and is generally greater than 60%.

[0036] Here, by way of example, the components in the above optical module other than the silicon photonics chip 31 and the heat sink can be collectively referred to as the light source.

[0037] The optical module in this embodiment encapsulates the light generator and collimating lens within a housing, eliminating the need for a standard coaxial cap and reducing the overall size of the light source. Furthermore, the housing offers better sealing, effectively isolating external moisture and extending the lifespan of the light generator. By reflecting light to a preset direction through an optical path deflection element, the light signal can be transmitted via optical fiber, further reducing the overall size of the light source. By sealing only the light generator and collimating lens, eliminating the need for overall encapsulation, the overall size of the light source is further reduced, making optical path adjustment easier.

[0038] According to an optional embodiment of the present invention, the inner and outer walls of the side plates of the housing 21 separating the collimating lens 12 and the focusing lens are coated with an anti-reflection coating (ARC). This reduces light reflection and further improves the light transmittance of the side plates of the housing 21. Exemplarily, the anti-reflection coating is an anti-reflective coating.

[0039] According to an optional embodiment of the present invention, the side plate of the housing 21 separating the collimating lens 12 and the focusing lens is a flat plate made of silicon. Here, the side plate of the housing 21 is made of silicon, which allows for better light transmittance. Of course, silicon surfaces also exhibit significant Fresnel reflection, but this can be overcome by applying an anti-reflective coating. Due to the miniaturization requirements of the optical module, the light generator 11, collimating lens 12, focusing lens, and optical path deflection elements are all very small, and the housing 21 is also very small, with a length and width of approximately 2 mm and a wall thickness of approximately 0.2 mm. Therefore, using silicon to make the housing 21 allows for more precise dimensional control through etching processes, better meeting the miniaturization requirements of the optical module. Furthermore, it allows for better control of the roughness of the inner and outer walls of the housing 21, facilitating the application of an anti-reflective coating.

[0040] According to an optional embodiment of the present invention, the optical module further includes an isolator 13, which is disposed on a silicon photonic chip between the collimating lens 12 and the focusing lens, and is located within the sealed space. The isolator 13 can prevent the light generator 11 from being affected by reflected light, thus reducing its spectral purity, and is applicable to fiber optic communication or fiber optic sensing systems with high requirements for optical signal strength. The isolator 13 can be selected according to the actual application of the optical module.

[0041] According to an optional embodiment of the present invention, the housing 21 and the silicon photonic chip are connected by welding to form a sealed connection, which can effectively seal the connection and has low implementation cost.

[0042] The side plate of the housing 21, which contacts the silicon photonic chip, is coated with a metal plating layer to enhance the welding sealing performance. This allows the metal plating layer to fuse with the solder during welding, resulting in a stronger connection between the solder and the side plate of the housing 21.

[0043] According to an optional embodiment of the present invention, the solder used for welding the silicon photonic chip to the side plate of the housing 21 is gold-tin solder, and the metal plating layer is a gold plating layer. The gold-tin solder is pre-placed on the upper surface of the silicon photonic chip in the area corresponding to the housing cover, i.e., the welding area 22, and can be melted by heating and welded to the housing cover. The gold-tin alloy has a very high yield strength, and its strength is sufficient to meet the requirements of airtightness even at a temperature of 250-260°C. Therefore, when the components inside the housing 21, such as the light generator 11, generate heat during operation, causing the temperature of the housing 21 to rise, the weld joint can remain sealed. The fusion of the gold plating layer and the gold-tin solder is easier and stronger.

[0044] According to an optional embodiment of the present invention, the focusing lens and the optical path deflection element are bonded and fixed together. In this way, during optical path adjustment, the focusing lens and the optical path deflection element can be adjusted together, making the adjustment of the optical path simpler and more efficient. For example, optical signals can be easily coupled into a grating coupler (see description below), and the coupling structure has a large tolerance range.

[0045] Here, by way of example, the focusing lens may be a C-lens 14, with a planar end and a spherical end at its two ends. A C-lens is a microlens made of a special optical glass material. Compared with other self-focusing lenses, C-lens have many advantages, including low cost, low insertion loss, and a wider working distance range.

[0046] Here, exemplarily, the optical path deflection element is formed by bonding two prisms together. The bonding surface is an inclined plane with its upper end tilted towards the C-lens 14, and the inclined plane is coated with a reflective film. This allows the light emitted from the C-lens 14 to be reflected towards the silicon photonic chip 31. The two prisms are a first prism 151 and a second prism 152, as shown below. Figure 1 As shown, the first prism 151 is bonded and fixed to the C lens 14, and the second prism 152 is bonded and fixed to the first prism 151.

[0047] According to an optional embodiment of the present invention, the optical module further includes a heat sink 32 disposed on the upper surface of the silicon photonic chip 31, and the light generator 11, collimating lens 12, and isolator 13 are all disposed on the heat sink 32. The heat sink 32 is a miniature heat sink used to cool electronic chips. As described above, the light generator 11 is a laser chip that generates heat during operation; therefore, the heat sink 32 is used for cooling. Thus, this embodiment, with the heat sink 32, can be applied to high-power laser chips.

[0048] According to an optional embodiment of the present invention, the heat sink 32 is plated with multiple metal wires, which are electrically connected to the light generator 11. The metal wires can both provide electrical power to the light generator 11 and provide electrical signals to control its operation. Here, exemplarily, controlling the operation of the light generator includes when to emit light, what type of light to emit, etc., which will not be detailed. Since the metal wires are plated on the heat sink, the transmission of electrical power and signals is more reliable and stable, and no additional space is required. Exemplarily, the metal wires can be gold-plated wires, which makes signal transmission more sensitive and extends service life. Exemplarily, multiple metal wires can form a pattern of lines, which facilitates standardized manufacturing. Exemplarily, the heat sink 32 can also be provided with an identification pattern for mounting the laser chip, making mounting more accurate and convenient.

[0049] According to an optional embodiment of the present invention, the silicon photonic chip 31 is configured with a waveguide (not shown in the figure) and a grating coupler (not shown in the figure) disposed at one end of the waveguide, the grating coupler being used to receive light reflected from the optical path deflection element.

[0050] Exemplarily, the silicon photonic chip 31, heat sink 32, and light source can be part of the transmitting component of the optical module. Here, the waveguide is located on top of the silicon photonic chip 31 for transmitting optical signals, and other parts of the silicon photonic chip 31 can be used to house circuit components. In this way, the silicon photonic chip 31 can perform both electrical signal processing functions, such as electronic amplifiers and digital signal processors, and optical signal transmission, enabling functions such as optical signal filtering, beam splitting, and modulation. This achieves miniaturization, integration, and low cost of the optical module, meeting the high port density and low cost requirements of data centers. Furthermore, this embodiment of the invention further improves the miniaturization and integration of the optical module by improving the light source.

[0051] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0052] It should be noted that, in the embodiments of this invention, unless otherwise stated and limited, the term "connection" should be interpreted broadly. For example, it can refer to an electrical connection, or the internal connection between two components; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0053] In the embodiments of this invention, the terms "first," "second," and "third" are used only to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that "first," "second," and "third" can be interchanged in a specific order or sequence where permitted.

[0054] The specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction. For example, different combinations of specific technical features can form different embodiments and technical solutions. To avoid unnecessary repetition, the various possible combinations of the specific technical features in this invention will not be described separately.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optical module, characterized in that, The optical module includes a light generator, a collimating lens, a focusing lens, an optical path deflection element, a silicon photonics chip, and a housing for encapsulating the light generator. The light generator, collimating lens, focusing lens, and optical path deflection element are arranged sequentially on the silicon photonics chip along the propagation path of the light. The optical path deflection element is used to reflect the light emitted by the focusing lens to a preset direction. The housing forms an accommodating space with an opening facing the silicon photonic chip; the silicon photonic chip closes the opening of the accommodating space; the light generator and collimating lens are located inside the accommodating space; the focusing lens and optical path deflection element are located outside the accommodating space; the side plate of the housing between the collimating lens and the focusing lens is a light-transmitting structure; light passes through the side plate of the housing between the collimating lens and the focusing lens and is emitted from the collimating lens to the focusing lens; the focusing lens and the optical path deflection element are bonded and fixed together.

2. The optical module according to claim 1, characterized in that, The inner and outer walls of the side plate of the housing that separates the collimating lens and the focusing lens are coated with an anti-reflective coating.

3. The optical module according to claim 2, characterized in that, The side plate of the housing separating the collimating lens and the focusing lens is a flat plate made of silicon.

4. The optical module according to claim 1 or 2, characterized in that, The optical module also includes an isolator, which is disposed on a silicon photonic chip between the collimating lens and the focusing lens and is located within the accommodating space.

5. The optical module according to claim 1 or 2, characterized in that, The housing and the silicon photonic chip are connected by welding and sealing. The contact surface of the side plate of the housing that contacts the silicon photonic chip is plated with a metal coating to increase the welding and sealing performance.

6. The optical module according to claim 5, characterized in that, The solder used for welding the silicon photonic chip to the side plate of the housing is gold-tin solder, and the metal plating layer is a gold plating layer.

7. The optical module according to claim 4, characterized in that, The optical module also includes a heat sink disposed on the upper surface of the silicon photonic chip, and the light generator, collimating lens and isolator are all disposed on the heat sink.

8. The optical module according to claim 7, characterized in that, The heat sink is plated with multiple metal wires, which are electrically connected to the light generator.

9. The optical module according to claim 7, characterized in that, The silicon photonic chip is configured with a waveguide and a grating coupler disposed at one end of the waveguide. The grating coupler is used to receive light reflected from the optical path deflection element.

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