Narrow-linewidth single-polarization fiber laser using non-polarization optics

Area of Science:

• Photonics and Laser Technology
• Optical Engineering

Background:

• High-performance fiber lasers require single longitudinal mode and single polarization operation.
• Achieving these properties is challenging due to long cavities and standard optical fibers' lack of polarization selection.

Purpose of the Study:

• To demonstrate a simple and cost-effective all-fiber laser with narrow linewidth and single polarization.
• To achieve single longitudinal mode selection and linewidth reduction using an external high-Q fiber ring.

Main Methods:

• Implementation of an all-fiber laser system utilizing an external high-Q fiber ring.
• Employment of non-polarization fiber components and standard gain fiber.

Main Results:

• A single longitudinal mode fiber laser was successfully realized.
• A high polarization extinction ratio of approximately 40 dB was achieved.
• Low white frequency noise of 0.3 Hz²/Hz was recorded, corresponding to a fundamental linewidth of approximately 0.92 Hz.

Conclusions:

• The developed scheme offers a straightforward and economical method for creating narrow-linewidth, single-polarization fiber lasers.
• The laser design is suitable for broadband applications.
• The use of standard fiber components ensures cost-effectiveness.