3D Printed Lenses for Vertical Beam Collimation of Optical Phased Arrays

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Nanophotonics

Background:

• Optical phased arrays (OPAs) are crucial for beam steering applications.
• Efficient beam collimation is essential for outcoupled light from edge-coupled OPAs.
• Previous OPA designs faced limitations in beam quality and collimation.

Purpose of the Study:

• To design, fabricate, and characterize edge-coupled 1D OPAs integrated with collimating lenses.
• To compare the performance of commercially available lenses with custom 3D printed lenses for beam collimation.
• To demonstrate and analyze 1D beam steering capabilities with improved collimation.

Main Methods:

• Fabrication of two generations of 1D OPAs (37 and 512 channels) with 3-μm waveguide spacing.
• Integration of edge-coupled waveguide outputs with collimating lenses (commercial straight cylindrical and custom 3D printed curved cylindrical).
• Experimental demonstration of 1D beam steering via wavelength tuning around 1550 nm and analysis of beam parameters.

Main Results:

• Demonstrated maximum beam steering range of approximately 30°.
• Characterized collimation performance, yielding a Rayleigh range of 9.9 mm and divergence of 7.0 mrad (0.4°) with the commercial lens.
• Achieved significantly improved collimation with the 3D printed lens: 40.1 mm Rayleigh range and 3.5 mrad (0.2°) divergence.

Conclusions:

• Edge-coupled 1D OPAs combined with collimating lenses enable effective 1D beam steering.
• Custom 3D printed curved cylindrical lenses offer superior beam collimation compared to commercial straight lenses.
• The developed OPA system with enhanced collimation shows promise for advanced optical applications.