A 400G DR4 optical engine

Abstract

This utility model relates to a 400G DR4 optical engine. A vertical through-hole is formed along the upper edge of the base. The upper substrate of the TEC cooler is positioned above the through-hole, with its edge resting on the upper surface of the base. The lower substrate of the TEC cooler and the TEC chip are located within the through-hole. A heat sink and a lens are bonded to the upper substrate. An EML chip coupled to the lens is mounted on the heat sink. An optical fiber array is bonded to the upper surface of the base. An optical isolator is coupled between the lens and the optical fiber array, and the optical isolator is fixed to the end face of the optical fiber array. The advantages are: it eliminates the ±75μm thickness tolerance of the TEC cooler, leaving only the ±10μm thickness tolerance of the upper substrate, which has no impact on coupling efficiency. The optical fiber array is also located on the upper surface of the base, ensuring a small height error between the EML chip and the fiber core in the optical fiber array, thus solving the coupling efficiency problem and significantly improving yield. The adhesive thickness tolerance under the lens is small, resulting in higher reliability.

Description

Technical Field

[0001] This utility model relates to the field of optical engine technology, specifically to a 400G DR4 optical engine. Background Technology

[0002] Traditional 400G DR4 optical engines generally use TEC coolers to control the temperature of the EML chip. The structure of this 400G DR4 optical engine is as follows: Figure 1 , Figure 2 As shown, it includes: a base, a PCB board, and a TEC cooler. A through slot is opened vertically along the PCB board. The base has steps at its edge. The PCB board is fitted onto the base through the through slot. The steps of the base support the PCB board. The base is made of tungsten copper. The lower substrate of the TEC cooler is fixed to the upper surface of the base. Multiple heat sinks and multiple lenses arranged in rows are fixed on the upper substrate of the TEC cooler. The heat sinks are made of ceramic and are bonded to the upper substrate. The lenses are bonded to the upper substrate with UV adhesive. Each heat sink is bonded to the PCB board with high-frequency gold wire. Each heat sink is fixed with an EML chip. Each lens is coupled to an EML chip. An optical fiber array is bonded to the light-emitting side of the lens on the upper surface of the base. Each lens is coupled to each channel of the optical fiber array with an optical isolator. The optical isolator is fixed to the end face of the optical fiber array. The TEC cooler used in the 400G DR4 optical engine of this solution includes, from top to bottom, an upper substrate, a TEC chip, and a lower substrate. The upper and lower substrates are made of aluminum nitride ceramic. The TEC chip is soldered to both the upper and lower substrates. Typically, there is a thickness tolerance of ±75μm (the thickness tolerance of the upper and lower substrates can generally be ±10μm, which has no impact on coupling efficiency). This thickness tolerance arises from the soldering of the TEC chip and the upper substrate + TEC chip + lower substrate, which will cause the following defects: 1) Since the TEC cooler and fiber array are fixed on the same upper surface of the base, and the heat sink is fixed on the upper substrate of the TEC cooler, and the EML chip is then fixed on the heat sink, the EML chip and the fiber core of the fiber array have a large error in the height direction, resulting in a decrease in coupling efficiency and a poorer yield. 2) Large errors in the thickness of the UV adhesive under the lens reduce the reliability of the lens, decrease coupling efficiency, and worsen the yield. 3) When operating at high temperatures, the EML chip and lens are located on the cold side of the TEC cooler, while the fiber array is located on the hot side of the TEC cooler. Specifically, the heat generated by the hot side of the TEC cooler can be conducted to the fiber array through the tungsten copper base. Since tungsten copper is a material with a high thermal conductivity, typically 180 W / mk, this results in an excessive temperature difference between the three optical components, leading to a decrease in optical path stability. When operating at low temperatures, the EML chip and lens are located on the hot side of the TEC cooler, while the fiber array is located on the cold side of the TEC cooler. This also results in an excessive temperature difference between the three optical components, leading to a decrease in optical path stability.

[0003] Another type of 400G DR4 optical engine is like Figure 3 As shown, this scheme uses a large-size TEC cooler, placing the heat sink (EML chip on the heat sink), lens and fiber array all on the upper substrate of the TEC cooler. Although this solves the above problem, it introduces a new problem: the size of the TEC cooler increases, and the number of TEC chips increases accordingly, leading to an increase in the cost and power consumption of the TEC cooler. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a 400G DR4 optical engine to overcome the shortcomings of the prior art.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A 400G DR4 optical engine includes: a base and a TEC cooler. A through hole is vertically opened along the upper edge of the base. The upper substrate of the TEC cooler is located above the through hole and its edge rests on the upper surface of the base. The lower substrate of the TEC cooler and the TEC chip are located inside the through hole. A heat sink and a lens are bonded to the upper substrate. An EML chip coupled to the lens is provided on the heat sink. An optical fiber array is bonded to the light-emitting side of the lens on the upper surface of the base. An optical isolator is coupled between the lens and the optical fiber array. The optical isolator is fixed to the end face of the optical fiber array.

[0006] The beneficial effects of this utility model are: By placing the edge of the upper substrate of the TEC cooler on the upper surface of the base, and then suspending the lower substrate and TEC chip in the through hole, the heat sink and lens are bonded to the upper substrate, and the EML chip is placed on the heat sink. This eliminates the ±75μm thickness tolerance of the TEC cooler, leaving only the ±10μm thickness tolerance of the upper substrate. This thickness tolerance has no impact on the coupling efficiency. The fiber array is also located on the upper surface of the base, ensuring that the height error between the EML chip and the fiber core in the fiber array is small, thus solving the coupling efficiency problem and significantly improving the yield. The adhesive thickness tolerance under the lens is small, resulting in higher reliability. The asymmetric small-size TEC cooler is adopted, that is, the size of the upper substrate in the TEC cooler is larger than that of the lower substrate, and the number of TEC chips can be reduced. At the same time, the lower substrate and TEC chips are suspended and are not affected by high and low temperature thermal stress, thus improving reliability. The thickness of the TEC cooler is no longer limited to a thin size and can be made very thick. This allows the use of TEC chips of ordinary height, resulting in lower cost. The upper and lower substrates can also be thickened to increase the reliability of the TEC cooler. When operating at high temperatures, since the EML chip, lens, and fiber array are all located on the cold side of the TEC cooler, the temperature difference between the three is small, resulting in less temperature-induced deformation and a more stable optical path. Similarly, when operating at low temperatures, since the EML chip, lens, and fiber array are all located on the hot side of the TEC cooler, the temperature difference between the three is small, resulting in less temperature-induced deformation and a more stable optical path.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the upper substrate is made of aluminum nitride ceramic, and the lower substrate is made of aluminum nitride ceramic.

[0009] Furthermore, the upper substrate is bonded to the upper surface of the base.

[0010] Furthermore, the lens is bonded to the upper surface of the upper substrate using UV adhesive.

[0011] Furthermore, a thermally conductive grease is coated on the lower surface of the lower substrate, and the thermally conductive grease coated on the lower surface of the lower substrate is below the lower surface of the base.

[0012] The further beneficial effect of the above-mentioned method is that when dissipating heat from the outer casing, only a small amount of thermal grease needs to be applied to the lower surface of the lower substrate, so that the thermal grease on the lower surface of the lower substrate can contact the bottom shell in the outer casing. Compared with the prior art, which requires applying thermal grease to the lower surface of the base, the amount of thermal grease used can be reduced.

[0013] Furthermore, the base is made of tungsten copper.

[0014] Furthermore, there are four heat sinks arranged in a row; there are four EML chips, each fixed on one of the four heat sinks; there are four lenses, each coupled to one EML chip; the fiber array is a four-channel fiber array, and there are four optical isolators, with each lens coupled to one optical isolator between each channel of the four-channel fiber array.

[0015] Furthermore, it also includes: a PCB board with a vertical through-slot along its upper edge, a step on the edge of the base, the PCB board being fitted onto the base through the through-slot, the step on the base supporting the PCB board, and the heat sink being made of ceramic, which is bonded to the PCB board using high-frequency gold wire. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the first scheme of the 400G DR4 optical engine in the prior art; Figure 2 This is a top view of the first proposed solution for a 400G DR4 optical engine in the prior art; Figure 3 This is a structural diagram of the second scheme of the 400G DR4 optical engine in the prior art; Figure 4 This is a structural diagram of the 400G DR4 optical engine in this utility model; Figure 5 This is a top view of the 400G DR4 optical engine in this utility model.

[0017] The attached diagram lists the components represented by each number as follows: 1. Base, 110. Through hole, 120. Step, 2. TEC cooler, 210. Upper substrate, 220. Lower substrate, 230. TEC chip, 3. Heat sink, 4. Lens, 5. EML chip, 6. Fiber optic array, 7. Optical isolator, 8. UV adhesive, 9. PCB board, 910. Through slot, 10. Thermal grease, 11. High-frequency gold wire. Detailed Implementation

[0018] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0019] Example 1 like Figure 4 , Figure 5As shown, a 400G DR4 optical engine includes: a base 1 and a TEC cooler 2. A through-hole 110 is vertically formed along the upper edge of the base 1, meaning the through-hole 110 penetrates both the upper and lower surfaces of the base 1. The TEC cooler 2 includes: an upper substrate 210, a lower substrate 220, and a TEC chip 230 located between the upper substrate 210 and the lower substrate 220. The upper substrate 210 of the TEC cooler 2 is positioned above the through-hole 110, and its edge rests on the upper surface of the base 1. Specifically, the size of the upper substrate 210 is smaller than the size of the through-hole 110, while the lower substrate 230... The substrate 220 and the TEC chip 230 are located within the through hole 110. That is, the size of the upper substrate 210 is larger than that of the lower substrate 220. The heat sink 3 and the lens 4 are bonded to the upper substrate 210. The heat sink 3 is provided with an EML chip 5 coupled to the lens 4. The fiber array 6 is bonded to the light-emitting side of the lens 4 on the upper surface of the base 1. The lens 4 and the fiber array 6 are coupled with an optical isolator 7. The optical isolator 7 is fixed to the end face of the fiber array 6. The emitted light of the EML chip 5 can be coupled into the fiber array 6 after passing through the lens 4 and the optical isolator 7 in sequence. The upper substrate 210 of the TEC cooler 2 is placed on the upper surface of the base 1, and the lower substrate 220 and TEC chip 230 are suspended in the through hole 110. The heat sink 3 and lens 4 are bonded to the upper substrate 210, and the EML chip 5 is placed on the heat sink 3. This eliminates the ±75μm thickness tolerance of the TEC cooler 2, leaving only the ±10μm thickness tolerance of the upper substrate 210. This thickness tolerance has no effect on the coupling efficiency. The fiber array 6 is also located on the upper surface of the base 1, ensuring that the height error between the EML chip 5 and the fiber core in the fiber array 6 is small, thus solving the coupling efficiency problem and greatly improving the yield. The adhesive thickness tolerance under the lens 4 is small, resulting in higher reliability. An asymmetric small-size TEC cooler 2 is adopted, that is, the size of the upper substrate 210 in the TEC cooler 2 is larger than that of the lower substrate 220, and the number of TEC chips 230 can be reduced. At the same time, the lower substrate 220 and TEC chips 230 are suspended and are not affected by high and low temperature thermal stress, thus improving reliability. The thickness of the TEC cooler 2 is no longer limited to a thin size, and it can be made very thick. This allows the use of TEC chips 230 of ordinary height, resulting in lower cost. The upper substrate 210 and the lower substrate 220 can also be thickened, increasing the reliability of the TEC cooler 2. When operating at high temperatures, since the EML chip 5, lens 4, and fiber array 6 are all located on the cold side of the TEC cooler 2, the temperature difference between the three is small, resulting in less deformation caused by temperature and a more stable optical path. Similarly, when operating at low temperatures, since the EML chip 5, lens 4, and fiber array 6 are all located on the hot side of the TEC cooler 2, the temperature difference between the three is small, resulting in less deformation caused by temperature and a more stable optical path.

[0020] Example 2 like Figure 4 , Figure 5 As shown, this embodiment is a further improvement on embodiment 1, as detailed below: The upper substrate 210 is made of aluminum nitride ceramic, and the lower substrate 220 is also made of aluminum nitride ceramic, which is consistent with the existing technology.

[0021] Furthermore, the upper substrate 210 is bonded to the upper surface of the base 1.

[0022] Lens 4 is preferably bonded to the upper surface of the upper substrate 210 using UV adhesive 8, which is consistent with the existing technology.

[0023] Example 3 like Figure 4 , Figure 5 As shown, this embodiment is a further improvement on embodiment 1 or 2, as detailed below: The lower surface of the lower substrate 220 is coated with thermal grease 10. The thermal grease 10 coated on the lower surface of the lower substrate 220 is below the lower surface of the base 1. When dissipating heat with the outer casing, only a small amount of thermal grease 10 needs to be applied to the lower surface of the lower substrate 220 so that the thermal grease 10 on the lower surface of the lower substrate 220 contacts the bottom shell in the outer casing. Compared with the prior art, which requires applying thermal grease 10 to the lower surface of the base 1, the amount of thermal grease 10 used can be reduced.

[0024] Furthermore, the base 1 is preferably made of tungsten copper, which is consistent with existing technology.

[0025] Example 4 like Figure 4 , Figure 5 As shown, this embodiment is a further improvement on embodiment 1, 2, or 3, as detailed below: There are four heat sinks 3, arranged in a row; there are also four EML chips 5, which are fixed on the four heat sinks 3 respectively; there are also four lenses 4, each coupled to one EML chip 5; the fiber array 6 is a four-channel fiber array, and there are four optical isolators 7. Each lens 4 is coupled to one optical isolator 7 between each channel of the four-channel fiber array, so the whole scheme has four transmission beams.

[0026] Example 5 like Figure 4 , Figure 5 As shown, this embodiment is a further improvement on any one of embodiments 1 to 4, as detailed below: The 400G DR4 optical engine also includes: a PCB board 9, with a vertical through-slot 910 along the upper edge of the PCB board 9, and a step 120 on the edge of the base 1. The PCB board 9 is fitted onto the base 1 through the through-slot 910, and the step 120 of the base 1 supports the PCB board 9. The heat sink 3 is made of ceramic and is bonded to the PCB board 9 with high-frequency gold wire 11, which is consistent with the existing technology.

[0027] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A 400G DR4 optical engine, characterized in that, include: The base (1) and the TEC cooler (2) are provided. A through hole (110) is opened vertically through the base (1). The upper substrate (210) of the TEC cooler (2) is above the through hole (110) and its edge rests on the upper surface of the base (1). The lower substrate (220) of the TEC cooler (2) and the TEC chip (230) are located in the through hole (110). A heat sink (3) and a lens (4) are bonded to the upper substrate (210). An EML chip (5) coupled to the lens (4) is provided on the heat sink (3). An optical fiber array (6) is bonded to the light-emitting side of the lens (4) on the upper surface of the base (1). An optical isolator (7) is coupled between the lens (4) and the optical fiber array (6). The optical isolator (7) is fixed on the end face of the optical fiber array (6).

2. A 400G DR4 optical engine according to claim 1, characterized in that, The upper substrate (210) is made of aluminum nitride ceramic, and the lower substrate (220) is made of aluminum nitride ceramic.

3. A 400G DR4 optical engine according to claim 1 or 2, characterized in that, The upper substrate (210) is bonded to the upper surface of the base (1).

4. A 400G DR4 optical engine according to claim 1 or 2, characterized in that, The lens (4) is bonded to the upper surface of the upper substrate (210) using UV adhesive (8).

5. A 400G DR4 optical engine according to claim 1 or 2, characterized in that, The lower surface of the lower substrate (220) is coated with thermally conductive grease (10), and the thermally conductive grease (10) coated on the lower surface of the lower substrate (220) is below the lower surface of the base (1).

6. A 400G DR4 optical engine according to claim 1 or 2, characterized in that, The base (1) is made of tungsten copper.

7. A 400G DR4 optical engine according to claim 1, characterized in that, The number of heat sinks (3) is four, and the four heat sinks (3) are arranged in a row; the number of EML chips (5) is four, and the four EML chips (5) are fixed on the four heat sinks (3) respectively; the number of lenses (4) is four, and each lens (4) is coupled to one EML chip (5); the fiber array (6) is a four-channel fiber array, the number of optical isolators (7) is four, and each lens (4) is coupled to each channel of the four-channel fiber array with one optical isolator (7).

8. A 400G DR4 optical engine according to claim 1 or 7, characterized in that, Also includes: The PCB board (9) has a through slot (910) vertically through its upper edge. The base (1) has a step (120) on its edge. The PCB board (9) is fitted onto the base (1) through the through slot (910). The step (120) of the base (1) supports the PCB board (9). The heat sink (3) is made of ceramic and is bonded to the PCB board (9) with high-frequency gold wire (11).

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