Ultrabroad Brillouin instantaneous frequency measurement with a designed linear system response

Area of Science:

• Photonics and optical engineering
• Signal processing and communications

Background:

• Instantaneous frequency measurement (IFM) is crucial for analyzing fast-varying signals.
• Stimulated Brillouin scattering (SBS) offers a potential platform for high-bandwidth IFM.
• Achieving linearity in SBS-based systems is challenging but essential for performance.

Purpose of the Study:

• To demonstrate an ultrabroadband IFM system based on SBS.
• To investigate the role of a designed linear system response in enhancing IFM performance.
• To minimize measurement errors and maximize the operational bandwidth of the IFM system.

Main Methods:

• Developed a novel linear system response for SBS-based IFM.
• Optimized the sweeping method for frequency and amplitude of the local pump signal.
• Employed Costas and linear frequency modulated (LFM) signals for system validation.

Main Results:

• Achieved an ultrabroad instantaneous bandwidth for IFM.
• Demonstrated successful measurement of a 10.5 GHz Costas signal.
• Extended the system bandwidth to 14.5 GHz through pump signal optimization.
• Maintained a measurement error of less than 1% for LFM signals up to 20.5 GHz.

Conclusions:

• A designed linear system response is key to broadening SBS-based IFM bandwidth.
• The developed system offers high accuracy and ultrabroadband capabilities for frequency measurement.
• This advancement has significant implications for high-speed optical signal analysis and communications.