Near-Field-Focusing Integrated Optical Phased Arrays

Integrated optical phased arrays that focus radiated light to a tightly-confined spot in the near field are demonstrated for the first time. The element phase distributions necessary for generating and steering focused beams using phased arrays are developed. Discussion and simulations detailing the effects of the array aperture and focal length on the focal spot are included. Two focusing phased array architectures are presented: (1) a one-dimensional splitter-tree-based architecture with novel focusing antennas and inline phase bumps and (2) a two-dimensional large-scale pixel-based architecture. Both architectures are used to experimentally demonstrate a variety of aperture size and focal length passive focusing arrays in a CMOS-compatible platform, including (i) a 512-antenna splitter-tree-based array with a wavelength-steerable 7 µm spot at a 5 mm focal length, (ii) a 1024-antenna pixel-based array with a 21 µm spot at a 5 mm focal length, and (iii) a 10,000-antenna pixel-based array with a 21 µm spot at a 10 mm focal length. The demonstrated focusing phased arrays present a new functional modality compared to standard optical phased arrays that generate diffracting beams in the far field of the array. This new focusing modality has the potential to advance a number of important application areas at the cutting edge of lightwave technology, as it will enable future integrated optical phased array implementations for a wide range of applications that require focusing operation. Such areas include optical trapping for biological characterization, laser-based three-dimensional printing, short-range light detection and ranging, and short-range optical data communications.

[1]  Michael R. Watts,et al.  Large-scale nanophotonic phased array , 2013, Nature.

[2]  C. Bustamante,et al.  Ten years of tension: single-molecule DNA mechanics , 2003, Nature.

[3]  Ali Hajimiri,et al.  Nanophotonic projection system. , 2015, Optics express.

[4]  Miloš A Popović,et al.  Finite-difference complex-wavevector band structure solver for analysis and design of periodic radiative microphotonic structures. , 2015, Optics letters.

[5]  Ranjeet Kumar,et al.  High-resolution aliasing-free optical beam steering , 2016 .

[6]  Michael R. Watts,et al.  Lens-Free Chip-to-Chip Free-Space Laser Communication Link with a Silicon Photonics Optical Phased Array , 2017 .

[7]  Matthew J. Byrd,et al.  Large-scale silicon nitride nanophotonic phased arrays at infrared and visible wavelengths. , 2017, Optics letters.

[8]  Eric R. Anschuetz,et al.  Atom-by-atom assembly of defect-free one-dimensional cold atom arrays , 2016, Science.

[9]  Federico Capasso,et al.  Metalenses: Versatile multifunctional photonic components , 2017, Science.

[10]  Jie Sun,et al.  Large-Scale Silicon Photonic Circuits for Optical Phased Arrays , 2014, IEEE Journal of Selected Topics in Quantum Electronics.

[11]  Tin Komljenovic,et al.  Sparse aperiodic arrays for optical beam forming and LIDAR. , 2017, Optics express.

[12]  G. Lo,et al.  A compact and low loss Y-junction for submicron silicon waveguide. , 2013, Optics express.

[13]  Michael R. Watts,et al.  Design of 3D Hologram Emitting Optical Phased Arrays , 2015 .

[14]  Matthew J. Byrd,et al.  CMOS-Compatible Optical Phased Arrays with Monolithically-Integrated Erbium Lasers , 2018, 2018 Conference on Lasers and Electro-Optics (CLEO).

[15]  David B. Cole,et al.  Coherent solid-state LIDAR with silicon photonic optical phased arrays. , 2017, Optics letters.

[16]  R. Poprawe,et al.  Laser additive manufacturing of metallic components: materials, processes and mechanisms , 2012 .

[17]  Peter J. Pauzauskie,et al.  Optical trapping and integration of semiconductor nanowire assemblies in water , 2006, Nature materials.

[18]  D. Grier.  A revolution in optical manipulation , 2003, Nature.

[19]  Jie Sun,et al.  Two-dimensional apodized silicon photonic phased arrays. , 2014, Optics letters.

[20]  Michael R. Watts,et al.  An ultra low power 3D integrated intra-chip silicon electronic-photonic link , 2015, 2015 Optical Fiber Communications Conference and Exhibition (OFC).

[21]  S. H. Lee,et al.  Two-dimensional spatial light modulators: a tutorial , 1990, Proc. IEEE.

[22]  Simon Hanna,et al.  Holographic optical trapping of microrods and nanowires. , 2010, Journal of the Optical Society of America. A, Optics, image science, and vision.

[23]  L. Coldren,et al.  Fully integrated hybrid silicon two dimensional beam scanner. , 2015, Optics express.

[24]  Rajeev J. Ram,et al.  Ultra-efficient CMOS fiber-to-chip grating couplers , 2016, 2016 Optical Fiber Communications Conference and Exhibition (OFC).

[25]  Hossein Hashemi,et al.  15.4 A 1024-element scalable optical phased array in 0.18µm SOI CMOS , 2017, 2017 IEEE International Solid-State Circuits Conference (ISSCC).

[26]  Michael R Watts,et al.  Integrated optical phased arrays for quasi-Bessel-beam generation. , 2017, Optics letters.

[27]  Mincheng Zhong,et al.  Trapping red blood cells in living animals using optical tweezers , 2013, Nature Communications.

[28]  Rajeev J. Ram,et al.  Precise and diffraction-limited waveguide-to-free-space focusing gratings , 2016, Scientific Reports.