Mode-locked fiber laser with a fiber phase modulator

Area of Science:

• Optics and Photonics
• Laser Physics
• Fiber Optics

Background:

• Mode-locked fiber lasers are crucial for generating ultrashort optical pulses.
• Traditional mode-locking techniques can involve complex setups or high losses.
• Developing efficient and stable mode-locking methods for fiber lasers remains an active research area.

Purpose of the Study:

• To demonstrate frequency modulation (FM) mode-locked operation in a single-mode neodymium-doped (Nd3+) fiber laser.
• To utilize an integrated fiber phase modulator for achieving mode-locking.
• To evaluate the performance characteristics, including threshold, efficiency, pulse duration, repetition rate, and output power.

Main Methods:

• Implementation of an FM mode-locking scheme using an integrated fiber phase modulator within the laser cavity.
• Configuration of a low-loss cavity design for the Nd3+-doped fiber laser.
• Characterization of the laser output, including pulse duration, repetition rate, and average power.

Main Results:

• Successful achievement of stable FM mode-locked operation.
• Observation of ~200-picosecond (psec) pulse durations.
• Generation of pulses at a repetition rate of 417 megahertz (MHz).
• Attainment of an average output power of 15 milliwatts (mW).
• Demonstration of low threshold and high slope efficiency due to the low-loss cavity.

Conclusions:

• FM mode-locking with an integrated fiber phase modulator is an effective technique for single-mode Nd3+ fiber lasers.
• The low-loss cavity configuration enables efficient laser operation with a low threshold and high slope efficiency.
• The demonstrated laser system provides a stable source of picosecond pulses at a high repetition rate, suitable for various applications.