Photonic instantaneous frequency measurement using a dense wavelength-division multiplexer

Area of Science:

• Photonics
• Microwave Engineering
• Optical Signal Processing

Background:

• Accurate and wide-range instantaneous frequency measurement (IFM) is crucial for various applications, including electronic warfare and radar systems.
• Traditional IFM techniques often face limitations in terms of measurement range, accuracy, or complexity.
• Photonic approaches offer potential advantages for high-performance IFM due to the inherent high bandwidth of optical components.

Purpose of the Study:

• To propose and experimentally demonstrate a novel photonic instantaneous frequency measurement receiver.
• To leverage frequency-to-optical power mapping for accurate microwave signal analysis.
• To achieve a wide measurement range and high accuracy simultaneously without complex multi-step operations.

Main Methods:

• Utilizing a channel of a dense wavelength-division multiplexer (DWDM) as a quasi-linear optical filter for frequency-to-power conversion.
• Employing a stable laser source and a bias controller to ensure consistent performance.
• Establishing a power ratio function based on the microwave signal's frequency and the DWDM filter's characteristics.

Main Results:

• The proposed receiver demonstrated accurate instantaneous frequency measurements over a broad range (1-40 GHz).
• A high measurement accuracy of 0.2% of the signal frequency was achieved.
• Stable performance was maintained over an experimental duration of 1.5 hours.

Conclusions:

• The demonstrated photonic IFM receiver offers a promising solution for high-performance frequency measurement applications.
• The use of a DWDM filter provides a unique advantage with its smooth, quasilinear roll-off characteristics.
• Simultaneous achievement of wide measurement range and high accuracy without multi-step operations marks a significant advancement.