Optical Module Accelerate into the Era of Silicon Photonics

At present, the 400G optical module has entered the stage of commercial deployment in the world, and the prototype development and technical standards of the 800G optical module are in progress, and the 1.6Tb/s optical module may become the next hot spot in the global competition.

At present, there are mainly three types of optical modulation technologies in the industry, electro-optic modulators based on silicon photonics, indium phosphide, and lithium niobate material platforms. Silicon photonic modulators are mainly used in short-range data communication transceiver modules, and the market share of silicon photonic modules will begin to increase.

Optical chips are the key core devices in optical communication systems. As optical chips using silicon photonics technology, silicon photonic chips are new integrated circuits manufactured by using silicon photonic materials and devices through special processes. Compared with traditional III-V material optical chips, silicon optical chips have the characteristics of high integration, low cost, and good optical waveguide transmission performance due to the use of silicon as the integrated chip substrate.

In the joint development and functional verification of the 1.6Tb/s silicon-based optical transceiver chip, the researchers integrated 8-channel high-speed electro-optic modulators and high-speed optoelectronic The detector, each channel can realize the photoelectric and electro-optical conversion of 200Gb/s PAM4 high-speed signal, and finally passed the chip packaging and system transmission test, and completed the verification of optical interconnection technology with a single chip capacity up to 8×200Gb/s. The market will enter a new round of economic upward cycle in the next 3 to 5 years, and the turning point of the upstream optical moduleindustry is approaching. In terms of technology change, the scale of 400G has increased, and the industry has entered the initial stage of 800G iteration. Next year, the mass production of traditional discrete 800G is approaching, and it is necessary to focus on the progress of various manufacturers in the upcoming dividend period of technological change.

According to Lightcounting’s forecast, the global Top5 cloud computing companies (Alibaba, Amazon, Facebook, Google, Microsoft) will rapidly increase their demand for 800G optical modules from 2022, and it is expected to become the leading model in the datacom market in 2026. Top5 cloud computing companies will spend US$1.4 billion on Ethernet optical modules in 2020, and Lightcounting expects to exceed US$3 billion in 2026, of which 800G product demand will become the largest part.

On December 13, 2021, the MSA industry alliance for 1.6T optical interfaces was announced to be established, announcing that 1.6Tb/s optical modules will become the next hot spot in the global competition. According to Lightcounting statistics, the market share of SiP-based products has grown steadily since 2016, and the growth has accelerated after 2018. It predicts that the global silicon optical module market will be close to 8 billion US dollars in 2026, with a market share of over 50%. At the same time, the overall cumulative scale of silicon optical modules will be close to 30 billion US dollars from 2021 to 2026.

The advantages of silicon photonics integration include low power consumption, high integration, reduced volume, and faster connection speed through the transmission of information through photonic media. At the same time, silicon photonics technology can be used for batch testing through wafer testing and other methods, and the test efficiency is significantly improved. In addition, from the perspective of material cost, the traditional III-V material (GaAs/InP) substrate is limited by the growth of the wafer material, and the production cost is high. With the further increase of the transmission rate, a larger III-V substrate is required. Family wafers, the cost of chips will be further increased. Compared with III-V materials, silicon-based materials are lower in cost and can be manufactured in large sizes, so theoretically chip costs can be significantly reduced.

But at the same time, the current overall industrialization level of silicon photonics integration is not high, which also means that there is no mature industrial chain for wafer-level testing, and the chip yield rate is relatively low. The cost balance between silicon photonics technology and traditional discrete technology is at 400G. Compared with the traditional solution of 400G optical modules in data centers and the silicon photonics solution, silicon photonics has relatively little advantage. As the rate of optical modules evolves to a higher rate of 800G and above, subject to problems such as the price and supply capacity of traditional optical chips, the cost advantage of silicon photonics is expected to gradually become prominent. At the same time, with the development of the silicon optical module industry chain and technology mature, its penetration rate is expected to usher in an accelerated increase. Silicon photonics provides reliable optical chip solutions for broadband interconnection in next-generation data centers, and will provide strong support for the vigorous development of new technologies and new industries such as supercomputing and artificial intelligence.

In this case, the communication giants have already begun to quietly lay out. In recent years, including Cisco, Huawei, Ciena, Juniper, etc., have acquired silicon photonics technology through acquisitions. Taking Intel as an example, its previous vision of “integrated optical path” is determined to apply silicon photonics technology to the 100-billion-level IC market