Dual-wavelength rectangular pulse Yb-doped fiber laser using a microfiber-based graphene saturable absorber

Area of Science:

• Photonics and Laser Technology
• Materials Science

Background:

• Fiber lasers are crucial for various scientific and industrial applications.
• Graphene saturable absorbers offer unique nonlinear optical properties for laser pulse generation.
• Controlling laser pulse characteristics, like wavelength and duration, is essential for advanced applications.

Purpose of the Study:

• To demonstrate the generation of dual-wavelength rectangular pulses from a Ytterbium-doped fiber laser (YDFL).
• To investigate the tunability of pulse duration and the characteristics of the generated pulses.
• To explore switchable dual-wavelength operation using polarization control.

Main Methods:

• Utilized a microfiber-based graphene saturable absorber (GSA) within a Ytterbium-doped fiber laser cavity.
• Employed a tunable bandpass filter to analyze pulse characteristics at specific wavelengths.
• Adjusted pump power to control pulse duration and rotated polarization controllers (PCs) for wavelength switching.

Main Results:

• Successfully generated dual-wavelength rectangular pulses centered at 1061.8 nm and 1068.8 nm.
• Pulse duration was tunable from 1.41 ns to 4.23 ns by varying pump power.
• Demonstrated switchable dual-wavelength operation by manipulating polarization controllers.

Conclusions:

• The Ytterbium-doped fiber laser with a GSA can effectively generate tunable dual-wavelength rectangular pulses.
• The characteristics of the dual-wavelength pulses are similar, offering flexibility in applications.
• This work paves the way for novel applications in spectroscopy, biomedicine, and sensing research.