Differences And Similarities between Silicon Optical Modules And Ordinary Optical Modules

Definition of Silicon Optical Module and General Optical Module

Ordinary optical modules are usually coupled with high-speed circuit silicon chips, III-V semiconductor chips, optical components, and other devices.

Its development path follows Moore's law, in essence, belongs to the "electrical interconnection", but with the transistor processing size gradually shrinking, the transmission bottleneck faced by the electrical interconnection tends to be urgent, the manufacturing of ordinary optical modules are also faced with Moore's law failure of the situation, the silicon optical module came into being.

An optical module that employs silicon photonics technology is called a silicon optical module.

"Light instead of electricity"—that is, transmitting data using laser beams rather than electrical signals—is the fundamental idea of silicon optical modules.

Silicon photonics technology aims to accomplish the full meaning of "optical interconnection" by combining optical and electrical signal processing onto a single microchip. This is achieved by combining silicon optical modules in optical devices with electronic components.

Silicon optical module and ordinary optical module technology characteristics

Ordinary optical module is to achieve photoelectricity conversion device, its function needs to modulate and receive optical signals. In order to obtain a high degree of integration between modulators, receivers, and passive optical devices, ordinary optical modules must be created by packaging electrical chips, optical chips, lenses, alignment components, optical fiber end face, and other devices. Each device is mainly integrated through packaging technology.

Silicon photonic technology used in silicon optical module is the use of CMOS process for the development and integration of optical devices, silicon optical module’s chip integration sets apart itself, and it is based on the CMOS manufacturing process, is the biggest difference between silicon optical module and ordinary optical module.

By using silicon wafer technology, etching on a silicon substrate, epitaxial growth, and other processing processes, a high degree of integration between modulators, receivers, and passive optical devices is accomplished.

What are the advantages of silicon optical module compared with ordinary optical module

Compared with ordinary optical modules, silicon optical modules have low power consumption, high integration and high speed and other advantages, for the need to use a large number of optical modules for the data centre, silicon optical module is still the most significant advantage of low cost.

Silicon optical modules make use of silicon photonic technology to achieve a high degree of integration of modulators and passive optical paths on the chip, and the cost of optical module chips has been significantly reduced. Ordinary optical module using discrete structure, optical device components, packaging process is more complex, and thus need to invest in more labour costs, while the silicon optical module due to a high degree of integration of the chip, components and labour costs are relatively reduced.

In the 100G short distance CWDM4 and 100G medium and long distance coherent optical modules, silicon optical module cost advantage is not obvious. In 400G and above high speed scenarios, where traditional DML and EML costs are higher, the cost advantage of silicon optical modules is more significant.

Market Outlook

The rapid development of 5G downstream applications such as Telematics, AR/VR, live broadcasting and the megatrend of enterprises going to the cloud has driven the demand for data centre networks to iterate from 100G to 400G. Although the overall advantage of the silicon optical module solution is not yet obvious in view of the yield and loss issues, the low cost advantage of silicon optical modules in the ultra-400G short-distance scenarios, and in coherent optical scenarios may make them become the mainstream products of the data centre networks to be upgraded to 400G. Upgrade to 400G mainstream products.

Due to the more mature technology of ordinary optical modules and lower requirements for the deployment environment, it is difficult for silicon optical modules to be rolled out on a large scale in the market in the short term. And optical modules in the production of silicon optical devices in the early stage of large investment, in the absence of a certain scale effect, the relevant manufacturers of silicon optical module investment is relatively cautious, its shipments are thus limited. Therefore, the ordinary optical module is still the mainstream choice of the current market, silicon optical module of large-scale volume and spread still need time.