Bandpass filter and frequency-time mapping method for pulse measurement with optical delay.

Area of Science:

• Photonics
• Signal Processing
• Electrical Engineering

Background:

• Pulse signals with transients and low duty cycles present challenges in accurate signal capture and amplitude measurement.
• Existing methods struggle with excessive signal omission and erroneous readings due to these characteristics.

Purpose of the Study:

• To develop an improved system for capturing and measuring pulse signals with enhanced accuracy.
• To overcome limitations of transient and low duty cycle pulse signal characteristics.

Main Methods:

• A combined microwave photonics frequency-time mapping and optical delay electrical pulse measurement system was developed.
• A long optical fiber with multiple paths was used to extend the pulse duration, increasing the duty cycle.
• A bandpass filter was employed to exclude low-frequency ranges and mitigate phase noise effects.

Main Results:

• The system successfully stretched a 25 μs pulse with a 50 μs period to a continuous wave.
• Signal-to-noise ratio (SNR) was improved by 7 dB, demonstrating enhanced signal capture quality.
• Phase noise issues induced by multiple optical delay paths were effectively resolved.

Conclusions:

• The proposed system significantly enhances the possibility of capturing weak pulse signals.
• The combined approach effectively addresses challenges posed by transient and low duty cycle pulses.
• This method offers a viable solution for improving SNR and measurement accuracy in pulse signal analysis.