High power microsecond fiber laser at 1.5 μm

Area of Science:

• Laser Physics and Photonics
• Optical Engineering

Background:

• High-power fiber lasers are crucial for various scientific and industrial applications.
• Controlling pulse shape and minimizing amplified spontaneous emission (ASE) are key challenges in laser system design.

Purpose of the Study:

• To demonstrate a single-frequency, high-power fiber laser system capable of generating controllable rectangular-shaped microsecond (μs) pulses.
• To introduce a novel method for controlling ASE and mitigating pulse steepening during amplification.

Main Methods:

• Utilized a fiber laser system operating at 1550 nm.
• Employed a new method incorporating two seed sources at 1550 nm and 1560 nm to manage ASE and pulse shape.
• Implemented an electronically configurable design for on-the-fly adjustments of repetition rate and pulse duration.

Main Results:

• Achieved an output power of approximately 35 W in continuous wave (CW) mode and a peak power of around 32 W in pulsed mode.
• Demonstrated tunable repetition rates from 50 Hz to 10 kHz and adjustable pulse durations from 10 μs to 100 μs.
• Confirmed excellent long and short-term stability, along with superior spectral and spatial beam quality.

Conclusions:

• The developed fiber laser system successfully generates high-power, controllable rectangular μs pulses.
• The dual-seed source method effectively addresses ASE and pulse steepening issues.
• The system's tunable parameters and stability make it a promising tool for diverse applications requiring precise optical pulse generation.