Tunable noise-like pulse and Q-switched erbium-doped fiber laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Fiber Lasers

Background:

• Mode-locked lasers are crucial for generating ultrashort pulses.
• Er-doped fiber (EDF) lasers offer advantages in the 1550 nm spectral region.
• Achieving switchable operation between different pulse formats (e.g., NLPs and Q-switched) in a single laser cavity is challenging.

Purpose of the Study:

• To propose and experimentally demonstrate a novel switchable, widely wavelength-tunable laser.
• To achieve both noise-like pulse (NLP) and Q-switched pulse generation within a single linear cavity EDF laser.
• To investigate the performance characteristics and tuning ranges of both operating modes.

Main Methods:

• Utilized a linear cavity Er-doped fiber laser design.
• Employed a semiconductor saturable mirror (SESAM) for mode-locking.
• Incorporated a tunable filter (TF) to achieve wavelength tunability and switch between NLP and Q-switched modes.
• Experimentally characterized output power, spectral bandwidth, pulse energy, and peak power.

Main Results:

• Achieved net-normal-dispersion mode-locked NLP operation with a 57 nm tuning range (1528-1585 nm).
• NLPs produced a maximum average output power of 16 mW and peak power of 58.8 W at 1555 nm.
• Obtained stable Q-switched pulses with a 67 nm tuning range (1518-1585 nm).
• Maximum Q-switched pulse energy reached 231.4 nJ with a peak power of 278.8 mW at 1555 nm.

Conclusions:

• The proposed laser design successfully enables switchable operation between NLPs and Q-switched pulses.
• The laser exhibits wide wavelength tunability in both operating modes.
• The simple and versatile nature of this fiber laser makes it suitable for diverse practical applications.