Reference Number: ARL-SRP-00080
Project Description
Development of a Monolithic 1060 nm Figure-9 Ultrafast Fiber Laser
The Challenge & Objective
Ultrafast lasers operating in the 1-micron wavelength regime are essential tools for precision materials processing, biomedical imaging, and fundamental optical research. However, traditional mode-locked lasers often rely on delicate free-space alignments or fragile physical saturable absorbers that degrade over time and fail under high-power conditions. This project addresses the critical need for an environmentally stable, reliable, and high-power laser seed source. The primary objective is to design, construct, and characterize a monolithic, self-starting 1060 nm Figure-9 Polarization-Maintaining (PM) fiber laser operating at a 30 MHz repetition rate.
Technical Execution & Methodology
To achieve this, the researcher will implement an all-fiber, closed-loop cavity using a Nonlinear Amplifying Loop Mirror (NALM) as an artificial saturable absorber. Because NALM-based designs can struggle to initiate pulsing spontaneously, a passive $\pi/2$ non-reciprocal phase shifter will be integrated into the loop to bias the cavity for guaranteed self-starting operation.
The work will involve:
Developing custom fusion-splicing recipes to couple active ytterbium-doped PM fiber to passive PM fiber with low insertion loss and high polarization purity.
Assembling a monolithic fiber cavity to completely eliminate free-space drift.
Establishing a stable, all-normal dispersion regime to generate high-energy dissipative solitons.
Tools & Expected Outcomes
The researcher will utilize specialized optoelectronic diagnostics, including:
A high-resolution PM fusion splicer for precise physical alignment.
An optical spectrum analyzer (OSA) to verify the characteristic steep-edged spectral profile.
A high-speed photodiode paired with an oscilloscope and RF spectrum analyzer to validate a clean 30 MHz pulse train with high signal-to-noise ratio.
The final deliverable will be a fully functional, self-starting ultrafast laser prototype and a comprehensive performance mapping report, demonstrating a ruggedized seed source ready for integration into larger laser systems.
Technical Skills
- Artificial Intelligence/Machine Learning
- Electrical Engineering
- Mathematics
- Physics
- Electronics
