NLFM waveform generation using tunable integrated optical ring resonators: simulation and proof of concept...

Area of Science:

• Photonics and Optical Engineering
• Signal Processing
• LIDAR Technology

Background:

• Nonlinear frequency modulation (NLFM) waveforms are crucial for advanced LADAR systems.
• Optimizing NLFM waveforms requires minimizing sidelobe levels and Full Width at Half Maximum (FWHM) times for better range resolution and performance.
• Integrated optical ring resonators offer a potential platform for generating tunable NLFM waveforms.

Purpose of the Study:

• To simulate and experimentally validate the generation of NLFM waveforms using tunable integrated optical ring resonators.
• To evaluate the autocorrelation properties, specifically first sidelobe levels and FWHM times, of the generated NLFM waveforms.
• To assess the suitability of these waveforms for LADAR applications.

Main Methods:

• Simulation of NLFM waveform generation using a series of tunable integrated optical ring resonators.
• Analysis of autocorrelation functions to determine first sidelobe levels and FWHM times.
• Experimental proof-of-concept using a thermally tunable silicon-nitride optical ring resonator.

Main Results:

• Simulations demonstrated that the maximum sidelobe level of the autocorrelation for NLFM waveforms is -20 to -30 dB or lower.
• The generated NLFM chirped waveforms exhibited a bandwidth of 28 kHz in the proof-of-concept experiment.
• These results indicate a significant reduction in sidelobe levels, beneficial for LADAR.

Conclusions:

• Tunable integrated optical ring resonators can effectively generate NLFM waveforms with low sidelobe levels.
• The experimental results validate the simulation findings, confirming the potential of this technology for LADAR.
• This approach offers a promising pathway for developing high-performance LADAR systems with improved range resolution.