Integrated optical phased arrays for quasi-Bessel-beam generation

Area of Science:

• Photonics
• Optical Engineering
• Integrated Optics

Background:

• Bessel beams feature elongated central beams, making them valuable for applications such as multiparticle trapping and laser lithography.
• Generating Bessel beams typically requires complex optical setups, limiting their widespread adoption.

Purpose of the Study:

• To propose and experimentally demonstrate integrated optical phased arrays for generating quasi-Bessel beams.
• To adapt continuous Bessel theory for on-chip generation of Bessel-Gauss beams using optical phased arrays.
• To investigate the impact of phased array parameters on beam quality.

Main Methods:

• Utilized continuous Bessel theory to derive phase and amplitude conditions for on-chip Bessel-Gauss beam generation.
• Modified a 1D splitter-tree-based phased array architecture for arbitrary passive control of element phase and amplitude.
• Experimentally validated the proposed method using the modified phased array architecture.

Main Results:

• Successfully demonstrated on-chip generation of quasi-Bessel beams.
• Achieved a Bessel length of approximately 14 mm.
• Obtained a power full width at half maximum of approximately 30 μm.

Conclusions:

• Integrated optical phased arrays offer a viable platform for generating quasi-Bessel beams in a CMOS-compatible manner.
• The developed architecture provides precise control over beam characteristics, paving the way for advanced optical applications.
• This work advances on-chip beam shaping capabilities for micro- and nano-scale manipulation.