Sub-picosecond pulse generation employing an SOA-based nonlinear polarization switch in a ring cavity

Area of Science:

• Optics and Photonics
• Semiconductor Lasers
• Ultrafast Optics

Background:

• Semiconductor optical amplifiers (SOAs) are crucial components in optical communication and signal processing.
• Passive mode-locking is a key technique for generating ultrashort optical pulses, essential for high-speed applications.
• Ring laser configurations offer stable platforms for pulse generation and manipulation.

Purpose of the Study:

• To demonstrate the generation of sub-picosecond optical pulses using a novel configuration.
• To investigate the potential of nonlinear polarization rotation in SOAs for passive mode-locking.
• To achieve high repetition rates for practical applications.

Main Methods:

• Utilizing a semiconductor optical amplifier (SOA) within a ring-laser cavity.
• Employing a linear polarizer to induce nonlinear polarization rotation for passive mode-locking.
• Characterizing the generated optical pulses, including duration and repetition rate.

Main Results:

• Generation of optical pulses with a full width at half maximum (FWHM) duration below 800 femtoseconds (fs).
• Achieved a pulse repetition rate of 14 MHz.
• Measured a time-bandwidth product of 0.48, indicating near-transform-limited pulses.
• Experimental results showed good agreement with theoretical simulations.

Conclusions:

• The SOA-based ring laser with nonlinear polarization rotation is an effective method for generating sub-picosecond optical pulses.
• This technique provides a compact and potentially cost-effective solution for ultrafast pulse generation.
• The achieved pulse characteristics are promising for various applications in nonlinear optics and high-speed optical systems.