How does light signal transmit information?

Optical networks typically refer to optical communication networks, and their transmission medium is optical fiber.

When you speak into your phone, take photos, or record videos, the sound, images, and videos are transformed by electronic signal transmission devices into electric currents, which become a series of digital signals composed of "0s" or "1s". These signals are then transmitted through optical fibers, sending solid or weak light from an optical transmitter to another optical receiver. The receiving end then converts the signals back into sound or image signals, allowing people far away to hear the sound and see the images. This is the working principle of optical fiber communication.

Optical fiber communication has accelerated the speed of information transmission, putting information on the highway. The capacity of optical fiber communication is astonishingly large; on a single optical fiber thinner than a hair strand, tens of thousands of telephone calls or thousands of TV programs can be transmitted simultaneously. Optical fiber communication also has the advantages of good security and strong anti-interference capabilities, making it widely used.

Optical network technology refers to the network structure technology that uses optical fiber for transmission. Optical network technology is not just a simple optical fiber transmission link, but a technology that utilizes the large capacity, long distance, and high reliability provided by optical fibers. It achieves multi-node network interconnection and flexible scheduling through optical and electronic control technologies.

Optical networks generally refer to wide area networks, metropolitan area networks, or newly built large local area networks that use optical fibers as the main transmission medium.

Core components of optical networks: Optical modules are optical devices used for photoelectric conversion and electro-optical conversion, consisting of optical devices, functional circuits, and optical interfaces. The optical devices include a transmission part and a reception part. The transmission end converts electrical signals into optical signals, which are then transmitted through optical fibers. The reception end converts the optical signals back into electrical signals, so optical modules are also known as optical transceivers. Although optical modules are small in size and relatively simple in structure, they have high technical requirements.

With the accelerated growth of internet traffic in recent years, optical modules have played an important role in long-distance communication, data centers, 5G applications, fiber to the home, and other scenarios. Common packages include SFP, SFP+, SFP28, QSFP+, QSFP28, QSFP56, QSFP-DD, with rates of 100M, 1.25G, 10G, 25G, 40G, 100G, 200G, 400G respectively.

They are mainly used in Ethernet, fiber channel, OTN, InfiniBand, SDH, SONET, and can also be used in fiber converters, switches, fiber routers, fiber network cards, communication base stations, and other devices. Different packages have different transmission rates, transmission distances, and application ranges.