Perturbing period-one laser dynamics for frequency-modulated microwave generation with external locking

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Dynamics

Background:

• Frequency-modulated continuous-wave (FMCW) generation is crucial for applications like optical ranging and spectroscopy.
• External locking techniques are employed to stabilize and control laser frequency combs.
• Period-one (P1) laser dynamics offer a platform for complex optical signal generation.

Purpose of the Study:

• To develop a novel method for FMCW generation utilizing externally locked laser dynamics.
• To enhance the performance of FMCW generation through coherent combining of two lasers.
• To investigate the interplay between external locking and frequency modulation in laser systems.

Main Methods:

• Perturbing the period-one (P1) dynamics of two lasers under common injection.
• Employing slow modulation for adiabatic sweeping and fast modulation for external locking.
• Coherently combining laser outputs to boost central frequency.
• Analyzing the competition between external locking and frequency modulation.

Main Results:

• Demonstrated FMCW generation with a 6 GHz sweep range and 42 dB comb contrast.
• Achieved a central frequency of 4f0, reaching 80 GHz.
• Identified an optimal strength for locking the entire comb despite inherent competition.
• Showcased wide tuning capabilities of the central frequency.

Conclusions:

• The proposed method successfully generates externally locked FMCW signals with enhanced performance.
• The study reveals critical insights into the dynamics of externally locked laser systems.
• This technique offers a promising avenue for advanced optical sensing and communication systems.