Free-space to single-mode collection efficiency enhancement using photonic lanterns

Area of Science:

• Optics and Photonics
• Optical Engineering

Background:

• Free-space optical systems often face challenges with efficient light collection, especially from diffuse or scattered sources.
• Standard single-mode fibers have limitations in collecting light over varying distances and from non-ideal targets.

Purpose of the Study:

• To demonstrate enhanced single-mode collection efficiency for free-space optical systems.
• To evaluate the performance of a photonic lantern in collecting scattered infrared light.
• To assess the suitability of photonic lanterns for coherent detection systems.

Main Methods:

• Utilizing a photonic lantern to collect scattered infrared light from diffuse objects at near- and far-field distances.
• Comparing the collection efficiency of the photonic lantern with standard single-mode fiber.
• Analyzing the insertion loss properties of the photonic lantern under different conditions.

Main Results:

• Achieved a single-mode collection efficiency improvement of approximately 8 dB in the near-field region compared to standard single-mode fiber.
• Observed an additional insertion loss penalty for near-field distances when the transmitted beam was collimated.
• Demonstrated nearly perfect mode matching for collected light.

Conclusions:

• Photonic lanterns offer significant improvements in single-mode collection efficiency for free-space optical systems.
• The technology is well-suited for coherent detection applications, including light detection and ranging (LiDAR) and free-space optical communication.
• Further analysis of insertion loss is needed for specific near-field collimated beam scenarios.