Lasers for coherent optical satellite links with large dynamics

Area of Science:

• Optical physics
• Satellite geodesy
• Atmospheric optics

Background:

• Accurate ground-to-satellite ranging is crucial for satellite tracking and geodesy.
• Atmospheric turbulence poses a significant challenge to the stability and accuracy of optical links.
• Existing systems often lack the required frequency stability or sweep capabilities for advanced applications.

Purpose of the Study:

• To experimentally realize a laser system for ground-to-satellite optical Doppler ranging.
• To meet the stringent requirements of high frequency stability and large, controlled frequency sweeps.
• To develop a compact and robust system suitable for deployment at astronomical observation sites.

Main Methods:

• Development of a novel laser system with precise frequency control.
• Characterization of frequency stability at the 10^-14 level.
• Demonstration of large (±12 GHz) and rapid (>100 MHz/s) frequency sweeps.
• Integration with satellite ranging telescopes.

Main Results:

• Experimental realization of the laser system meeting all specified requirements.
• Achieved frequency stability of a few parts in 10^-14.
• Demonstrated frequency sweeps of ±12 GHz at rates exceeding 100 MHz/s.
• System confirmed to be compact and robust for field deployment.

Conclusions:

• The developed laser system successfully meets the demanding requirements for ground-to-satellite optical Doppler ranging.
• The system's performance is limited only by atmospheric turbulence, paving the way for high-precision measurements.
• This technology enables the operation of coherent optical links to low Earth orbit satellites.