Photonic integration technology is the mainstream direction of future optical device development

Photonic Integrated Circuit, referred to as PIC, is also called photonic integrated circuit. An optical waveguide type integrated circuit that integrates optical devices with a dielectric waveguide as the center, that is, an optical circuit that integrates several optical devices on a substrate to form a whole, and the devices are connected by semiconductor optical waveguides to make them have certain functions. Today, I will talk to you about photonic integration technology.

The concept of photonic integrated circuits is similar to that of electronic integrated circuits, and the difference between them lies in the different components. Electronic integrated circuits integrate electronic devices such as transistors, capacitors, and resistors, while photonic integrated circuits integrate various optical or optoelectronic devices, such as lasers, electro-optic modulators, photodetectors, optical attenuators, and optical multiplexing. / Demultiplexer and Optical Amplifier, etc.

In order to facilitate the understanding of photonic integration technology, functionally, it can be divided into passive PIC and active PIC. From the perspective of integration, it can be divided into three categories: small-scale PIC, medium-scale PIC and large-scale PIC. Among them, large-scale PIC can achieve photonic integration to the greatest extent. From the perspective of long-term development, large-scale PIC is the future photonic integration. Direction of development. Finally, as with the division of electronic integrated circuits, PICs can also be divided into monolithic integrated PICs and hybrid integrated PICs.

In the future high-speed, large-capacity information network system, photonic integration technology will become the main technology. Compared with the traditional discrete optical-electrical-optical (OEO) processing method, the cost and complexity are reduced, the reliability is improved, and a new network structure with more nodes is constructed. As early as 1969, Stewart E. Miller proposed photonic integrated circuits in his article. The development of electronic integrated current has always followed Moore's Law. After half a century of development, this law has gradually shown a trend of failure. According to Moore's Law, electronic integrated circuits have entered a bottleneck period, which requires new forces to drive industrial development.

Four major drivers for photonic integration applications: data center interconnection requirements, trunk ultra-large-capacity transmission requirements, operator display requirements in metro applications, and optical system development requirements. First, as the speed continues to increase, optical fibers will replace copper cables as the main transmission medium in cloud data centers. This demand manifests itself in the need for low cost and low power consumption for interconnected applications in the data center. Second, with the emergence of 400G and 1T requirements, there is also an urgent need for the small size and high density of the card board. Third, some operators lack maintenance capabilities due to backward historical development, and hope to integrate some optical layer functions of traditional wavelength division to reduce floor space and power consumption. Finally, the stacking method of discrete components that is widely used in the current wavelength division system not only has a large volume of boards, but also requires a large number of optical fiber connections between boards, resulting in low reliability. In general, photonic integration is driven by cost and emerged to meet market demands for lower power consumption, higher density and higher data transmission.