Photorefractive power transfer from parallel laser diode amplifiers into a single output beam

Area of Science:

• Materials Science
• Optics and Photonics
• Solid-State Physics

Background:

• Coherent beam combination is crucial for high-power laser systems.
• Photorefractive materials offer unique properties for optical wavefront control.
• Semiconductor laser amplifiers provide high gain for laser beam amplification.

Purpose of the Study:

• To investigate the coherent combination of a signal beam with amplified pump beams using photorefractive BaTiO3:Ce.
• To achieve efficient power transfer to the signal beam.
• To mitigate phase distortion transfer from pump beams to the signal beam.

Main Methods:

• Utilized cerium-doped barium titanate (BaTiO3:Ce) as the photorefractive medium.
• Employed semiconductor laser amplifiers with quantum-well laser chips and antireflection coating for beam amplification.
• Coherently combined a signal beam with two amplified pump beams at a wavelength of 678 nm.

Main Results:

• Achieved a power transfer efficiency of 40% to the signal beam.
• Demonstrated effective suppression of phase distortions from the pump beams.
• Obtained a gain of up to 6 in the semiconductor laser amplifiers.

Conclusions:

• Photorefractive BaTiO3:Ce is effective for coherent beam combination with high power transfer.
• The method successfully transfers power without inheriting phase distortions from pump beams.
• This technique holds promise for applications requiring high-intensity, phase-controlled laser beams.