Applications of Fiber Delay Lines

Introduction to Fiber Delay Line

It is a device that can realize the time delay of optical signals. By using delays, functions such as phase shifting and all-optical storage can be achieved. It has a wide range of applications in fields such as phased array radar, fiber optic communication systems, electronic countermeasures, and scientific research and testing. This article will start from the basic principles of fiber delay lines and expand around application scenarios.

Working Principle of Fiber Delay Line

The basic principle of the fiber delay line is that the optical signal to be delayed passes through a certain length of optical fiber. Since it takes a certain amount of time for the light to travel through the fiber, the time delay of the optical signal is realized.

Working principle: The RF signal to be transmitted and the optical signal emitted by the laser are input into various modulators. The modulators modulate the RF signal onto the light to form an optical signal carrying RF information. The optical signal carrying RF information is coupled into the optical fiber link for transmission. After a period of time delay, it reaches the photodetector, which converts the received optical signal carrying RF information back into an electrical signal for output.

Application Scenarios of Fiber Delay Line

Phased Array Radar

The core component of phased array radar is the phased array antenna. Traditional radar antennas far fall short of the requirements of radar systems. However, fiber delay lines have their unique performance advantages in the application of phased array antennas, thus having significant scientific meaning in phased array radar.

Fiber Optic Communication Systems

Fiber delay lines can be used to implement specific coding schemes. By introducing different delays at different time points, coded signals with specific patterns can be generated, facilitating improved resistance to interference in digital communication systems. In addition, they can be used as temporary storage (buffer), to temporarily store certain data, etc. 

In short, due to their high bandwidth, low loss, and immunity to electromagnetic interference, fiber delay lines have a wide range of applications in many fields. Whether in communication, radar, navigation, or medical imaging, they play an important role.