Pulsed-pump phosphorus-doped fiber Raman amplifier around 1260 nm for applications in quantum non-linear optics

Area of Science:

• Fiber optics
• Quantum optics
• Non-linear optics

Background:

• Fiber Raman amplifiers are crucial for generating specific light wavelengths.
• Previous amplifiers had limitations in pulse duration and power efficiency.

Purpose of the Study:

• To develop a fiber Raman amplifier for nanosecond and sub-nanosecond pulses at 1260 nm.
• To achieve high peak power, gain, and precise pulse control.

Main Methods:

• Utilized a 4.5-m polarization-maintaining phosphorus-doped fiber.
• Pumped with 1080 nm, 3-ns pulses at 200 kHz repetition rate and 1.75 kW peak power.
• Employed sub-mW peak-power, 0.25 ns seed pulses from a narrow-linewidth CW laser.

Main Results:

• Achieved up to 1.4 kW peak power output with over 80% peak-power conversion efficiency.
• Obtained ultrahigh small signal gain of 90 dB and signal-to-noise ratio above 20 dB.
• Demonstrated generation of nearly transform-limited pulses up to 1 kW, with controllable chirp, width, and double pulses.

Conclusions:

• The developed fiber Raman amplifier offers high performance for 1260 nm pulses.
• Enables precise coherent control of atomic resonances, particularly for rubidium Rydberg state excitation.
• Opens avenues for advanced quantum non-linear optics applications.