Tunable single-frequency fiber laser based on the spectral narrowing effect in a nonlinear semiconductor optical...

Area of Science:

• Photonics and Laser Technology
• Nonlinear Optics
• Semiconductor Devices

Background:

• Single-frequency fiber lasers are crucial for applications requiring precise wavelength control.
• Achieving stable, tunable single-frequency operation often involves complex cavity designs or active stabilization.
• Nonlinear optical effects in semiconductor devices offer potential for novel laser functionalities.

Purpose of the Study:

• To propose and demonstrate a wavelength-tunable single-frequency fiber laser.
• To leverage the spectral narrowing effect in a nonlinear semiconductor optical amplifier (NL-SOA) for single-frequency operation.
• To achieve wide wavelength tunability and high side-mode suppression ratio (SMSR).

Main Methods:

• Incorporating a NL-SOA into a fiber laser cavity to induce spectral narrowing via inverse four-wave mixing.
• Utilizing a tunable filter (TF) within the cavity to control the lasing wavelength.
• Experimental evaluation of the laser's performance, including SMSR, spectral linewidth, and tuning range.

Main Results:

• Stable single-frequency lasing was achieved due to the spectral narrowing effect in the NL-SOA.
• The laser demonstrated a wide wavelength tuning range of 48 nm.
• A high side-mode suppression ratio (SMSR) of 55 dB and a spectral linewidth below 10.1 kHz were recorded.

Conclusions:

• The proposed fiber laser design effectively utilizes NL-SOA spectral narrowing for stable, tunable single-frequency operation.
• The demonstrated performance metrics (SMSR, linewidth, tuning range) are competitive for advanced photonic applications.
• This approach offers a promising method for developing compact and efficient tunable single-frequency fiber lasers.