Optical Transceivers: Illuminating Data Pathways
The demand for high-speed data transmission is increasing day by day in today’s digital world. Optical transceivers play an essential role in modern optical communication systems. An optical communication system includes three main components- a transmitter, a receiver, and an optical fiber. The optical transceiver module consists of transmitter and receiver modules, capable of transmitting and receiving data in both directions individually.
The transmitter module generally includes a light source such as a semiconductor laser diode or LEDs that emit light of a specific wavelength, and electronic circuitry converts electrical signals into an optical signal for transmission over optical fiber. The receiver module consists of a photodetector (e.g., photodiode), which receives the optical signals and converts them into electrical signals, and an electronic circuitry that amplifies the electric signals and extracts the transmitted data. This enables efficient and reliable transmission over long distances with minimal loss via fiber-optic cables.
Primarily, Optical transceivers are categorized into two types: Single-mode and multimode. Single-mode transceivers offer high bandwidth and long-distance transmission over single-mode fibers. These fibers have narrow core diameters that allow only a single light mode to propagate, resulting in less signal dispersion. These transceivers are suitable for applications that require high-speed data transmission over huge networks.
Multimode transceivers, however, are designed for a shorter distance transmission and use multimode fibers with large core diameters. Multimode transceivers are cost-effective and commonly used in local area networks (LANs) and short-range applications. However, in contrast, both single-mode and multimode optical transceivers are used in high-speed data communication applications.
‘Form factor’ is a term used to define the size, shape, transmission distance, data rate, and interface of an optical transceiver module. Form factors in optical transceivers are standardized according to the Multi-source agreement (MSA) to ensure compatibility and interoperability across multiple networking products.
Optical transceivers are categorized into different types based on their form factors. One commonly used transceiver is the Small Form-Factor Pluggable (SFP) transceiver. These transceivers are compact and hot-swappable, suitable for high-density installations. SFP transceivers support various data rates and can operate over single-mode and multimode optical fibers. These transceivers also come in various improved versions such as SFP+, which supports higher data rates, and BiDi (Bidirectional) SFP which uses wavelength division multiplexing (WDM) technology for transmitting and receiving the data from network devices (e.g., network switches or routers) via single optical fiber.
Quad Small Form-Factor Pluggable (QSFP) transceivers provide a higher data rate than SFP transceivers. These transceivers are commonly used in data centers and high-computing networks with high-density connectivity. QSFP+, QSFP28, and QSFP-DD are some QSFP transceivers' variants.
C Form-factor Pluggable (CFP) transceivers support large data rates and are primarily used in wide area networks (WAN), wireless base stations, and other high-capacity networks. These transceivers are larger than SFP and QSFP transceiver modules due to complex circuitry and high-power requirements.
Read more in the blog and Teardown report to understand various components used in optical transceiver modules and the market players and IP activities related to the optical transceivers.
Mayank Gupta
Senior Associate at Lumenci
Mayank has 7+ years of experience in the semiconductor and display tech industry. Formerly a Research Associate, Mayank has hands-on experience maintaining and handling many semiconductor devices and fabrication instruments. He has co-authored several research papers in the semiconductor domain. Mayank is a Master of Technology (MTech.) Microelectronics and VLSI Design from Motilal Nehru National Institute of Technology, Allahabad, India.