A continuously tunable and filterless optical millimeter-wave generation via frequency octupling

Area of Science:

• Photonics and Optical Communications
• Millimeter-Wave (MMW) Technology
• Signal Generation

Background:

• Optical millimeter-wave (MMW) signal generation is crucial for high-speed wireless communication systems.
• Existing methods often require complex optical filtering, limiting their integration into wavelength-division-multiplexing (WDM) systems.
• Achieving high sideband suppression and tunability remains a challenge for cost-effective MMW signal generation.

Purpose of the Study:

• To propose a novel, cost-effective, and continuously tunable optical millimeter-wave (MMW) signal generation technique.
• To demonstrate a filterless approach for generating MMW signals suitable for WDM systems.
• To achieve high undesired sideband suppression ratios for improved signal quality.

Main Methods:

• Employing frequency octupling for optical MMW signal generation.
• Utilizing an external modulator with a limited bandwidth.
• Experimental demonstration of V-band (60 GHz) and W-band (80 GHz) signal generation.

Main Results:

• Achieved optical MMW signals with 30-dB undesired sideband suppression ratios.
• Demonstrated filterless generation, enabling seamless integration into WDM systems.
• Experimentally verified 60-GHz and 80-GHz optical MMW signals, with a 60-GHz signal exhibiting a 50% duty cycle due to high sideband suppression.
• Measured single-sideband (SSB) phase noise of -73 dBc/Hz at 10 kHz for the 60-GHz signal.

Conclusions:

• The proposed filterless frequency octupling method is a viable solution for cost-effective optical MMW signal generation.
• The system's high sideband suppression and tunability make it suitable for V-band and W-band applications.
• The technique supports future ultra-high frequency MMW applications up to 320 GHz with existing modulator technology.