Hybrid laser-to-fiber coupler with a cylindrical lens

Area of Science:

• Optics and Photonics
• Optical Engineering

Background:

• Efficient laser-to-fiber coupling is crucial for optical communication and sensing systems.
• Existing coupling schemes often require complex alignment procedures and achieve suboptimal efficiency.

Purpose of the Study:

• To evaluate and compare different laser-to-fiber coupling schemes.
• To develop a simple, effective, and robust mounting structure for enhanced coupling efficiency.
• To assess the practical feasibility of the proposed coupling method in hermetically sealed laser packages.

Main Methods:

• Investigated various laser-to-fiber coupling techniques.
• Designed and fabricated a hybrid mounting structure featuring a copper mount with two vee grooves for precise alignment of optical elements.
• Utilized a cylindrical lens to optimize the laser beam for fiber coupling.
• Coupled lasers to multimode optical fibers with a half acceptance angle of 3-4 degrees.
• Mounted the developed couplers in hermetically sealed laser packages.

Main Results:

• A coupling scheme employing a cylindrical lens demonstrated significant effectiveness in enhancing coupling efficiency.
• The proposed hybrid mounting structure enabled alignment of optical elements without manual adjustment.
• An average coupling efficiency of approximately 50% was achieved using multimode optical fibers.
• The developed couplers were successfully integrated into hermetically sealed laser packages, confirming their practical utility.

Conclusions:

• The cylindrical lens coupling scheme, combined with the novel hybrid mounting structure, offers a simple yet effective solution for improving laser-to-fiber coupling efficiency.
• The achieved 50% average coupling efficiency is suitable for practical applications.
• The successful integration into sealed laser packages highlights the robustness and feasibility of this approach for real-world deployment.