Frequency-selectable microwave generation based on on-chip switchable spectral shaping and wavelength-to-time mapping

Area of Science:

• Photonics
• Microwave Engineering
• Integrated Optics

Background:

• Pulsed microwave signal generation is crucial for various applications.
• Existing methods often lack frequency tunability or require complex setups.

Purpose of the Study:

• To propose and demonstrate a novel scheme for photonic generation of pulsed microwave signals with selectable frequencies.
• To leverage spectral shaping and wavelength-to-time mapping for frequency control.

Main Methods:

• Utilized an integrated silicon-on-insulator (SOI) spectral shaping chip with an asymmetric Mach-Zehnder interferometer (MZI).
• Employed channel switching on the SOI chip for frequency selection.
• Applied wavelength-to-time mapping (WTTM) to convert shaped optical spectra into microwave pulses.

Main Results:

• Successfully generated microwave pulses with frequencies ranging from 3.6 GHz to 28.4 GHz.
• Achieved selectable frequencies using a single dispersive element (DE).
• Demonstrated the generation of optical spectra with uniform free spectral range (FSR) over broad bandwidths.

Conclusions:

• The proposed scheme offers a flexible and expandable method for photonic generation of selectable-frequency pulsed microwave signals.
• The use of integrated SOI technology and WTTM provides a compact and efficient solution.
• The technique shows high potential for future advancements in microwave signal generation.