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Characterization of SiN Integrated Optical Phased Arrays on a Wafer-Scale Test Station
Published on: April 1, 2020
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Highly efficient optical antenna with small beam divergence in silicon waveguides.
Optics Letters
|October 15, 2020
Summary
Researchers developed a novel silicon waveguide for optical phased arrays, achieving a record-long antenna length and ultra-narrow beam width for enhanced light detection and ranging. This breakthrough enables higher resolution and longer sensing ranges in photonic devices.
Area of Science:
- Photonics
- Metamaterials
- Optical Engineering
Background:
- Optical antennas are crucial for optical phased arrays in light detection and ranging (LiDAR).
- Achieving narrow beam widths requires long antenna lengths (millimeters), which are difficult with current silicon waveguide technology due to grating strength control limitations.
Purpose of the Study:
- To develop a surface-emitting silicon waveguide with significantly increased antenna length.
- To demonstrate a record-small beam divergence and high radiation efficiency for improved LiDAR performance.
Main Methods:
- Utilized a subwavelength metamaterial waveguide core.
- Implemented evanescent coupling with laterally separated radiative segments.
- Designed L-shaped surface-emitting segments to enhance radiation efficiency.
Main Results:
- Achieved a record antenna length of 3.65 mm in a silicon waveguide.
- Demonstrated a record-small far-field diffracted beam width of 0.025°.
- Obtained a high radiation efficiency of 72% at 1550 nm using L-shaped segments.
Conclusions:
- The new metamaterial-based silicon waveguide design overcomes previous limitations in antenna length.
- This technology offers a significant advancement for high-resolution, long-range LiDAR and other photonic applications.
