Coupling method for improving high and low temperature heat effect and silicon optical module

Abstract

The invention provides a coupling method for improving high and low temperature thermal effects and a silicon optical module, the silicon optical module comprises a silicon lens and a silicon optical chip, and the coupling method for improving the high and low temperature thermal effects comprises the step of completing coupling of the silicon lens and the silicon optical chip in a high temperature environment of 70 DEG C + / -5 DEG C. The high and low temperature effect can be effectively reduced, the performance of the silicon optical module is improved, the TE problem of the silicon optical module at high temperature relative to normal temperature can be reduced only through the change of the coupling environment temperature, no additional coupling structure is added, the operation is convenient, and the cost is low.

Description

Technical Field

[0001] This invention relates to optical communication device manufacturing technology, and more particularly to a coupling method for improving high and low temperature thermal effects and a silicon photonics module. Background Technology

[0002] High and low temperature thermal effects are a common problem in optical systems used in optical communication. These effects refer to the phenomenon where optical systems experience performance degradation or failure due to changes in the physical properties of materials caused by temperature variations in high or low temperature environments.

[0003] The emitting section of a high-speed silicon photonics module has a highly consistent structure: after the laser source emits light, it passes through a lens and isolator into the silicon photonics chip, is modulated, and then transmitted via a fiber optic array. During high and low temperature testing, the optical power attenuation caused by lens displacement can reach 2.5 dB, severely impacting module performance. Existing solutions generally use TEC temperature control or mechanical fine-tuning mechanisms to mitigate the performance degradation caused by high and low temperature effects. However, these solutions require additional functional structures, resulting in large size, high power consumption, and high cost. Summary of the Invention

[0004] To address the problems in the prior art, the present invention provides a coupling method for improving high and low temperature thermal effects, and also provides a silicon photonic module coupled using the aforementioned coupling method for improving high and low temperature thermal effects.

[0005] This invention provides a silicon photonics module coupling method to improve high and low temperature thermal effects. The silicon photonics module includes a silicon lens and a silicon photonics chip, and the coupling between the silicon lens and the silicon photonics chip is completed in a high temperature environment of 70℃±5℃.

[0006] The present invention is further improved, and the coupling method includes the following steps:

[0007] Step 1: Fix the silicon photonics chip, laser, and isolator onto the substrate;

[0008] Step 2: The laser emits a light source, which passes through a silicon photonics lens and an isolator before entering the silicon photonics chip;

[0009] Step 3: Under constant temperature conditions of 70℃±5℃, adjust the position of the silicon lens to achieve peak coupling efficiency;

[0010] Step 4: UV-curable adhesive is used to fill the gap between the silicon lens and the substrate, and then cured to obtain the final silicon photonic module.

[0011] In a further improvement to this invention, in step three, coupling is performed in a constant temperature chamber at 70°C.

[0012] The present invention is further improved by adjusting the position of the silicon lens using a six-axis coupler, with a positional accuracy of ±0.1μm.

[0013] The present invention also provides a silicon photonics module, which is coupled using the coupling method described above to improve the thermal effect at high and low temperatures. When the silicon photonics module operates at 0-25℃, it performs corresponding current compensation, and the amount of current compensation is determined by the incident light power.

[0014] Compared with existing technologies, the advantages of this invention are: it can effectively reduce high and low temperature effects simply by changing the coupling environment temperature, improve the performance of silicon photonic modules, reduce the TE problem of silicon photonic modules at high temperatures compared to room temperature, without adding additional coupling structures, making it easy to operate and low in cost. Furthermore, high-temperature coupling requires a lower laser current to achieve the same incident light PD value at 25°C compared to room-temperature coupling, thereby further reducing power consumption. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the optical path of the silicon photonics module of the present invention;

[0016] Figure 2 This is a schematic diagram comparing the slant efficiency of a conventional room-temperature coupled laser and the high-temperature coupled laser of this invention. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0018] like Figure 1 As shown, during coupling, the light emitted by the laser passes through a silicon lens and isolator before reaching the silicon photonic chip. Typically, the position of the silicon photonic chip on the tungsten-copper substrate is fixed, and the position of the silicon lens usually needs to be moved to maximize coupling efficiency. To overcome the need for TEC temperature control or mechanical fine-tuning mechanisms in existing technologies to improve optical path performance degradation caused by high and low temperature effects, this invention achieves coupling between the lens and the silicon photonic chip at 70℃±5℃ during silicon photonic module coupling. This reduces the TE (transmission distance) problem of the module at high temperatures relative to room temperature. The TE value of an optical module typically refers to its transmission distance and operating temperature range.

[0019] Specifically, the coupling method of the present invention includes the following steps:

[0020] Step 1: Fix the silicon photonics chip, laser, and isolator onto the tungsten copper substrate;

[0021] Step 2: The laser emits a light source, which passes through a silicon photonics lens and an isolator before entering the silicon photonics chip;

[0022] Step 3: Under constant temperature conditions of 70℃±5℃, adjust the position of the silicon lens to achieve peak coupling efficiency;

[0023] Step 4: UV-curable adhesive is used to fill the gap between the silicon lens and the substrate, and then cured to obtain the final silicon photonic module.

[0024] Preferably, in step three of this example, coupling is performed in a 70°C constant temperature chamber, and then the position of the silicon lens is adjusted by a six-axis coupler, achieving a positional accuracy of ±0.1μm.

[0025] In step four, after filling the gap between the silicon lens and the substrate with UV-curable adhesive, the silicon lens is then thermally cured by UV irradiation to fix its final position.

[0026] This invention effectively reduces high and low temperature effects simply by changing the coupling environment temperature, mitigating the voltage transfer (TE) problem of silicon photonic modules at high temperatures compared to room temperature. It does not require additional coupling structures, is easy to operate, and is low-cost. Furthermore, high-temperature coupling requires less laser current to achieve the same incident light PD value at 25°C compared to room-temperature coupling, thus further reducing power consumption.

[0027] Experimental verification:

[0028] The effectiveness of this invention was verified by coupling 12 optical modules of the same model and parameters. The incident light PD and TE values ​​(temperature effect values) of the high-temperature coupling and the traditional room-temperature coupling are shown in Table 1.

[0029] Table 1 Comparison of incident light PD and TE values ​​between high-temperature coupling and traditional room-temperature coupling

[0030]

[0031]

[0032]

[0033] As shown in Table 1, after coupling at 70℃, the silicon lens flat area is placed at the high-temperature operating point through high-temperature coupling. That is, under the condition of 70℃, the laser current required for high-temperature coupling to achieve the same incident light PD value at 25℃ is lower than that required for room-temperature coupling. The average TE value of high-temperature coupling is slightly worse at 0℃ (-0.3875 vs -0.2433), which is due to the superposition of the material shrinkage direction and the offset direction of high-temperature coupling. However, under the critical operating condition of 70℃, the average TE value is optimized by more than 30% (e.g., 0.1633 vs -0.1117). After coupling at 70℃, the optical power fluctuation within the temperature range of 25~70℃ is <0.4dB. Compared with the optical power attenuation of 2.5dB in the prior art, the present invention can significantly improve this.

[0034] This invention also provides a silicon photonics module, coupled using the aforementioned coupling method to improve high and low temperature thermal effects. When the silicon photonics module operates at 0-25℃, it performs corresponding current compensation, the amount of which is determined by the incident light power.

[0035] The laser current of the silicon photonics module of the present invention when operating at 0℃, 25℃ and 70℃ is shown in Table 2.

[0036] Table 2 Laser current of silicon photonics module when operating at 0℃, 25℃ and 70℃

[0037]

[0038]

[0039] The increase in low-temperature bias current (e.g., from 97mA to 114mA) in this invention is due to the optical path of high-temperature coupling deviating from its optimal point at low temperatures. To achieve the same incident light, current compensation is required, thus increasing the current. The effect after compensation is an improvement in the laser's slope efficiency at 70℃, which is represented by a smaller curve slope in the graph. Figure 2 As shown in the figure, the horizontal axis represents pump power, and the vertical axis represents laser output power. The slope efficiency of a laser refers to the ratio of net laser gain per unit length to pump power. In optical modules, slope efficiency is an important performance indicator, as it relates to the dynamic response of the optical signal. The slope represents the rate of change of optical power with current, while the slope efficiency is the maximum change in optical power at a specific current. Therefore, the slope efficiency of a laser directly affects the optical signal transmission efficiency and stability of the optical module. Figure 2 It is understood that the silicon photonics module of the present invention can improve the efficiency and stability of optical signal transmission. The present invention is particularly suitable for 400G / 800G silicon photonics modules that operate in a wide temperature range of 0 to 75°C.

[0040] The specific embodiments described above are preferred embodiments of the present invention and are not intended to limit the specific scope of the present invention. The scope of the present invention includes, but is not limited to, these specific embodiments. All equivalent changes made in accordance with the present invention are within the protection scope of the present invention.

Claims

1. A coupling method for a silicon optical module to improve high and low temperature thermal effects, the silicon optical module comprising a silicon lens and a silicon optical chip, characterized in that: The coupling between the silicon lens and the silicon photonic chip was completed in a high-temperature environment of 70℃±5℃.

2. The coupling method for improving high and low temperature thermal effects according to claim 1, characterized in that, The coupling method includes the following steps: Step 1: Fix the silicon photonics chip, laser, and isolator onto the substrate; Step 2: The laser emits a light source, which passes through a silicon photonics lens and an isolator before entering the silicon photonics chip; Step 3: Under constant temperature conditions of 70℃±5℃, adjust the position of the silicon lens to achieve peak coupling efficiency; Step 4: UV-curable adhesive is used to fill the gap between the silicon lens and the substrate, and then cured to obtain the final silicon photonic module.

3. The coupling method for improving high and low temperature thermal effects according to claim 1, characterized in that: In step three, coupling is performed in a 70℃ constant temperature chamber.

4. The coupling method for improving high and low temperature thermal effects according to claim 3, characterized in that: The position of the silicon lens is adjusted using a six-axis coupler with a positioning accuracy of ±0.1μm.

5. A silicon photonics module, coupled using the coupling method for improving high and low temperature thermal effects as described in any one of claims 1-4, wherein the silicon photonics module performs corresponding current compensation when operating at 0-25℃, and the amount of current compensation is determined by the incident light power.

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