Low-noise high-power dual-frequency MOPA laser with an NPRO seed

Area of Science:

• Photonics
• Laser Physics
• Optical Engineering

Background:

• Dual-frequency lasers are vital for applications like photonic microwave generation, lidar, and interferometry.
• Increasing the output power of dual-frequency lasers is essential for broader technological adoption.
• Achieving high power and low noise simultaneously in dual-frequency lasers presents a significant engineering challenge.

Purpose of the Study:

• To demonstrate a low-noise, high-power dual-frequency laser system.
• To investigate the feasibility of a master-oscillator-power-amplifier (MOPA) configuration for high-power dual-frequency lasers.
• To analyze and quantify phase noise contributions in the MOPA system.

Main Methods:

• Employed a master-oscillator-power-amplifier (MOPA) architecture.
• Utilized a dual-frequency monolithic nonplanar-ring-oscillator (NPRO) as the seed laser.
• Incorporated an ytterbium-doped fiber amplifier (YDFA) for power amplification.
• Developed a theoretical model to assess phase noise from the fiber amplifier.

Main Results:

• Achieved a dual-frequency laser output power of 5 W at 1064 nm.
• Maintained low phase noise for the 5.78 GHz beat signal: -116.6 dBc/Hz at 10 kHz and -152.3 dBc/Hz at 10 MHz.
• Demonstrated that phase noise introduced by the fiber amplifier is negligible in this configuration.

Conclusions:

• The MOPA configuration effectively generates low-noise, high-power dual-frequency lasers.
• The developed theoretical model provides a method for analyzing phase noise in similar systems.
• This high-power dual-frequency laser technology can significantly advance industrial, airborne, and spaceborne applications.