Haijie Zuo - Academia.edu (original) (raw)

Papers by Haijie Zuo

Research paper thumbnail of Integrated freeform optical couplers

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Jul 5, 2022

Research paper thumbnail of Integrated Quadratic Reflectors for High-Performance Optical Interconnects

2020 IEEE Photonics Conference (IPC)

We propose and experimentally demonstrate a new photonics interconnect approach based on on-chip ... more We propose and experimentally demonstrate a new photonics interconnect approach based on on-chip quadratic optical reflectors for interfacing a wide range of photonic devices. Here, we present its embodiments on compact waveguide bends and high performance fiber-to-chip optical couplers.

Research paper thumbnail of Focal shift of silicon microlens in mid-infrared regime

In this study, rigorous numerical calculation was utilized to characterize the focal properties o... more In this study, rigorous numerical calculation was utilized to characterize the focal properties of mid-infrared silicon microlens with the size about tens of micrometers. It is found that the focal shift phenomenon also exists in mid-infrared regime, which behaves differently from that of visual and near-infrared wavelength. Focal properties of silicon microlens were also measured experimentally, showing well coherence with simulation results. Our results provide systemic understanding of focal shift in mid-infrared regime, at that wavelength special consideration should be paid in micro-nano optics, especially with the integration between infrared optical system and other devices.

Research paper thumbnail of Compact and Fabrication-Tolerant Single-Mode Polymer Waveguide Bends

Frontiers in Optics / Laser Science, 2020

We propose and experimentally demonstrate a broadband, polarization-diverse compact bending desig... more We propose and experimentally demonstrate a broadband, polarization-diverse compact bending design for low-index-contrast waveguides, where light is re-directed via total internal reflection on an air-trench quadratic reflector surface with insertion loss of 0.3 dB.

Research paper thumbnail of High-Performance Single-Mode Polymer Waveguide Devices for Chip-Scale Optical Interconnects

2019 IEEE Optical Interconnects Conference (OI), 2019

Here we present next generation polymer-based singlemode waveguide devices and architectures for ... more Here we present next generation polymer-based singlemode waveguide devices and architectures for chip-scale photonic interconnections. A suite of optical devices are developed showing record low propagation loss, high-performance signal/power routing, and high-density inter-layer coupling. Flexible waveguide ribbons are further demonstrated that are widely applicable across chip- and board-domains.

Research paper thumbnail of Real-time, in-situ monitoring of Gamma radiation effects in packaged silicon photonic chips

Conference on Lasers and Electro-Optics, 2020

We measured in-situ gamma radiation effect and post-radiation relaxation behavior on packaged SiC... more We measured in-situ gamma radiation effect and post-radiation relaxation behavior on packaged SiC integrated photonic devices. A method to deconvolve the radiation responses from constituent materials was also proposed and validated.

Research paper thumbnail of Optical polarimetric elastography for biomechanical analysis

To make transformative leaps in human health and wellness, our approach to healthcare must be rei... more To make transformative leaps in human health and wellness, our approach to healthcare must be reimagined. Researchers are pursuing multiple avenues, such as integrating health monitoring systems into wearable devices and leveraging machine learning methods to analyze health data. However, many of these approaches are pursued in isolation, and the resulting data is not cross correlated. By working directly with clinicians and clinician-researchers as well as bioinformaticians, we are identifying and addressing their critical needs. This presentation will discuss a recently developed instrument for measuring the elasticity of living tissue. Inspired by conventional mechanical compression testing, the portable instrument replaces the conventional pressure sensor with an array of optical fiber polarimetric sensors to improve both the resolution and sensitivity. These improvements allow the mechanical properties of unprocessed, living, resected tissue to be analyzed. To date, animal tiss...

Research paper thumbnail of Compact and Fabrication-Tolerant Waveguide Bends Based on Quadratic Reflectors

Journal of Lightwave Technology, 2020

Research paper thumbnail of Seamless Hybrid-integrated Interconnect NEtwork (SHINE)

Optical Fiber Communication Conference (OFC) 2019, 2019

We describe an optical communication technology scalable across chip-, board-, and rack-interconn... more We describe an optical communication technology scalable across chip-, board-, and rack-interconnect levels for data centers. The approach claims high energy efficiency, large bandwidth density, and is compatible with standard area-bonding and pick-and-place chip assembly.

Research paper thumbnail of Low-Voltage, Coupled Multiple Quantum Well Electroreflective Modulators Towards Ultralow Power Inter-Chip Optical Interconnects

Journal of Lightwave Technology, 2020

An electroreflective modulator based on multiple-pass electroabsorption (EA) of coupled multiple ... more An electroreflective modulator based on multiple-pass electroabsorption (EA) of coupled multiple quantum wells (CMQWs) is demonstrated for integration with low-loss polymer optical waveguides towards inter-chip and on-board optical interconnects at 850 nm. Taking advantage of coupling between quantum states in MQWs, the top polymer cladding and the bottom Au mirror form a Fabry–Pérot cavity to further enhance the EA of CMQWs, thereby greatly improving the extinction ratio (ER) at a low voltage. The device achieves an ER of ∼6 dB and an insertion loss (IL) <3 dB at 2 V, notably outperforming conventional surface-incident EA modulators at the same driving voltage. A further optimized modulator design can achieve a peak ER of 9–12 dB at 2 V with a low IL of 2–3 dB and a relatively broad spectral bandwidth of ∼10 nm. The low capacitance and reverse bias operation at a low voltage potentially offer ∼10× lower power consumption compared to direct modulation of 850 nm lasers. This simple surface-incident CMQW modulator is a promising candidate for integration with ultralow power inter-chip and on-board interconnect architectures.

Research paper thumbnail of Design of Hybrid Plasmonic Multi-Quantum-Well Electro-Reflective Modulators Towards <100 fJ/bit Photonic Links

IEEE Journal of Selected Topics in Quantum Electronics, 2020

Realization of on-board and inter-chip optical interconnects requires a photonic data link with p... more Realization of on-board and inter-chip optical interconnects requires a photonic data link with power consumption well below their electrical counterparts (i.e., <<1 pJ/bit). Currently, directly modulating 850 nm vertical cavity surface emitting lasers at >50 Gb/s requires 2–4 pJ/bit/channel. External reverse-biased modulators could drastically reduce this power consumption. Here we design ultralow power GaAs/AlGaAs multi quantum well electro-reflective modulators operating at 1 V for facile integration with polymer “optical bridges”, utilizing coupled quantum confined Stark effect between adjacent quantum wells and optical coupling to hybrid surface plasmon-slab modes for significantly enhanced extinction ratio and spectral bandwidth. Distinctive from conventional electro-optical or electro-absorption modulators, this new design synergistically leverages ultra-large changes in both refractive index (|Δn|∼0.05) and absorption coefficient (Δα∼104 cm−1), achieving 35-50 dB extinction ratio at 1 V reverse bias with a low insertion loss of 1–3 dB, an incident angle tolerance of ∼5°, and a spectral bandwidth of 7–10 nm. The modulator power consumption is ∼1.9 fJ/bit without the need of thermal tuning, and the RC-limited bandwidth well exceeds 100 GHz. This new modulator enables high bandwidth and ultralow power optical interconnect networks at >100 Gb/s/channel and <100 fJ/bit/channel compatible with ever-scaling CMOS technologies.

Research paper thumbnail of Optical Free-Form Couplers for High-density Integrated Photonics (OFFCHIP): A Universal Optical Interface

Journal of Lightwave Technology, 2020

Research paper thumbnail of Real-time, in situ probing of gamma radiation damage with packaged integrated photonic chips

Photonics Research, 2019

Integrated photonics is poised to become a mainstream solution for high-speed data communications... more Integrated photonics is poised to become a mainstream solution for high-speed data communications and sensing in harsh radiation environments, such as outer space, high-energy physics facilities, nuclear power plants, and test fusion reactors. Understanding the impact of radiation damage in optical materials and devices is thus a prerequisite to building radiation-hard photonic systems for these applications. In this paper, we report real-time, in situ analysis of radiation damage in integrated photonic devices. The devices, integrated with an optical fiber array package and a baseline-correction temperature sensor, can be remotely interrogated while exposed to ionizing radiation over a long period without compromising their structural and optical integrity. We also introduce a method to deconvolve the radiation damage responses from different constituent materials in a device. The approach was implemented to quantify gamma radiation damage and post-radiation relaxation behavior of ...

Research paper thumbnail of Low loss, flexible single-mode polymer photonics

Research paper thumbnail of High‐Efficiency All‐Dielectric Metalenses for Mid‐Infrared Imaging

Advanced Optical Materials, 2017

Research paper thumbnail of CMOS compatible fabrication of micro, nano convex silicon lens arrays by conformal chemical vapor deposition

Research paper thumbnail of Topologically patterning of polyvinyl alcohol microstructures for vertical-/hybrid-aligned nematic liquid-crystal gratings doped with polyhedral oligomeric silsesquioxane nanoparticles

Chinese Optics Letters, 2015

We demonstrate a soft lithography approach for fabrication of a topographically patterned polyvin... more We demonstrate a soft lithography approach for fabrication of a topographically patterned polyvinyl alcohol (PVA) liquid-crystal (LC) alignment layer. This specific approach employs modified micromolding in capillaries for negative replication of the PVA microstructures on indium tin oxide (ITO) substrates from patterned poly(dimethylsiloxane) molds in a single step, leading to planar alignment on the desired regions. By doping with polyhedral oligomeric silsesquioxane nanoparticles, which can induce vertical alignment on bare ITO surfaces, periodic LC phase gratings based on an alternating vertical-aligned/hybrid-aligned nematic geometry are presented as an application, and a theoretical model was used to simulate and examine the experimental results.

Research paper thumbnail of Effect of In Diffusion on the Property of Blue Light-Emitting Diodes

Chinese Physics Letters, 2015

In diffusion to blue light-emitting diode (LED) wafers is performed by the inductive coupled plas... more In diffusion to blue light-emitting diode (LED) wafers is performed by the inductive coupled plasma (ICP) treatment of a covering layer of indium tin oxide (ITO) on the wafer surface. The electrical property of the p-type contact is improved and the redshift of photoluminescence (PL) from the InGaN quantum well of the wafer is found. Measurements by x-ray photoelectron spectroscopy (XPS) demonstrate that In atoms have diffused into p-GaN. Reflectance spectra of the sample surface reveal the variation caused by the ICP treatment. A model of compensation of the in-plane strain of the InGaN layer is used to explain the redshift of the PL data. Finally, LEDs are fabricated by using as-grown and ICP-treated wafers and their properties are compared. Under an injection current of 20 mA, LEDs with ICP-induced In doping show a decrease of 0.3V in the forward voltage and an increase of 23% in the light output, respectively.

Research paper thumbnail of Rigorous microlens design using vector electromagnetic method combined with simulated annealing optimization

Optics express, Jan 19, 2014

In this paper, finite-aperture diffractive optical element with its critical dimension smaller th... more In this paper, finite-aperture diffractive optical element with its critical dimension smaller than illumination wavelength is modeled and optimized using an integrated method. This method employs rigorous analysis model based on Finite Difference Time Domain (FDTD), and simulated annealing (SA) global search algorithm. Numerical results reveal that the diffraction efficiency of the 8-step microlens quickly climbs to its global optimum along with the optimization process, which manifests its global search ability. The design algorithm and implementation are discussed in details. Considering its time consuming efficiency and global search ability, our method provides valuable reference value in practical multistep microlens design.

Research paper thumbnail of A flexible polymer waveguide platform with low-loss optical interfaces

2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), 2021

Single-mode polymer photonics is important to short-reach data communications, photonic packaging... more Single-mode polymer photonics is important to short-reach data communications, photonic packaging, sensing, and biophotonic light delivery. Mechanical flexibility and manufacturing scalability (e.g., roll-to-roll fabrication compatibility) are among other advantages often cited for these polymer materials. Here we report here experimental demonstration of mechanically flexible waveguides fabricated by using commercial off-the-shelf biocompatible polymers that claim a record low propagation loss of 0.11 dB/cm near 850 nm wavelength ( Fig. 1a ). In addition to their low optical loss, the waveguides also exhibit excellent mechanical flexibility and ruggedness, capable of withstanding over 1,000 bending cycles at 2 mm bending radius [1] .

Research paper thumbnail of Integrated freeform optical couplers

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Jul 5, 2022

Research paper thumbnail of Integrated Quadratic Reflectors for High-Performance Optical Interconnects

2020 IEEE Photonics Conference (IPC)

We propose and experimentally demonstrate a new photonics interconnect approach based on on-chip ... more We propose and experimentally demonstrate a new photonics interconnect approach based on on-chip quadratic optical reflectors for interfacing a wide range of photonic devices. Here, we present its embodiments on compact waveguide bends and high performance fiber-to-chip optical couplers.

Research paper thumbnail of Focal shift of silicon microlens in mid-infrared regime

In this study, rigorous numerical calculation was utilized to characterize the focal properties o... more In this study, rigorous numerical calculation was utilized to characterize the focal properties of mid-infrared silicon microlens with the size about tens of micrometers. It is found that the focal shift phenomenon also exists in mid-infrared regime, which behaves differently from that of visual and near-infrared wavelength. Focal properties of silicon microlens were also measured experimentally, showing well coherence with simulation results. Our results provide systemic understanding of focal shift in mid-infrared regime, at that wavelength special consideration should be paid in micro-nano optics, especially with the integration between infrared optical system and other devices.

Research paper thumbnail of Compact and Fabrication-Tolerant Single-Mode Polymer Waveguide Bends

Frontiers in Optics / Laser Science, 2020

We propose and experimentally demonstrate a broadband, polarization-diverse compact bending desig... more We propose and experimentally demonstrate a broadband, polarization-diverse compact bending design for low-index-contrast waveguides, where light is re-directed via total internal reflection on an air-trench quadratic reflector surface with insertion loss of 0.3 dB.

Research paper thumbnail of High-Performance Single-Mode Polymer Waveguide Devices for Chip-Scale Optical Interconnects

2019 IEEE Optical Interconnects Conference (OI), 2019

Here we present next generation polymer-based singlemode waveguide devices and architectures for ... more Here we present next generation polymer-based singlemode waveguide devices and architectures for chip-scale photonic interconnections. A suite of optical devices are developed showing record low propagation loss, high-performance signal/power routing, and high-density inter-layer coupling. Flexible waveguide ribbons are further demonstrated that are widely applicable across chip- and board-domains.

Research paper thumbnail of Real-time, in-situ monitoring of Gamma radiation effects in packaged silicon photonic chips

Conference on Lasers and Electro-Optics, 2020

We measured in-situ gamma radiation effect and post-radiation relaxation behavior on packaged SiC... more We measured in-situ gamma radiation effect and post-radiation relaxation behavior on packaged SiC integrated photonic devices. A method to deconvolve the radiation responses from constituent materials was also proposed and validated.

Research paper thumbnail of Optical polarimetric elastography for biomechanical analysis

To make transformative leaps in human health and wellness, our approach to healthcare must be rei... more To make transformative leaps in human health and wellness, our approach to healthcare must be reimagined. Researchers are pursuing multiple avenues, such as integrating health monitoring systems into wearable devices and leveraging machine learning methods to analyze health data. However, many of these approaches are pursued in isolation, and the resulting data is not cross correlated. By working directly with clinicians and clinician-researchers as well as bioinformaticians, we are identifying and addressing their critical needs. This presentation will discuss a recently developed instrument for measuring the elasticity of living tissue. Inspired by conventional mechanical compression testing, the portable instrument replaces the conventional pressure sensor with an array of optical fiber polarimetric sensors to improve both the resolution and sensitivity. These improvements allow the mechanical properties of unprocessed, living, resected tissue to be analyzed. To date, animal tiss...

Research paper thumbnail of Compact and Fabrication-Tolerant Waveguide Bends Based on Quadratic Reflectors

Journal of Lightwave Technology, 2020

Research paper thumbnail of Seamless Hybrid-integrated Interconnect NEtwork (SHINE)

Optical Fiber Communication Conference (OFC) 2019, 2019

We describe an optical communication technology scalable across chip-, board-, and rack-interconn... more We describe an optical communication technology scalable across chip-, board-, and rack-interconnect levels for data centers. The approach claims high energy efficiency, large bandwidth density, and is compatible with standard area-bonding and pick-and-place chip assembly.

Research paper thumbnail of Low-Voltage, Coupled Multiple Quantum Well Electroreflective Modulators Towards Ultralow Power Inter-Chip Optical Interconnects

Journal of Lightwave Technology, 2020

An electroreflective modulator based on multiple-pass electroabsorption (EA) of coupled multiple ... more An electroreflective modulator based on multiple-pass electroabsorption (EA) of coupled multiple quantum wells (CMQWs) is demonstrated for integration with low-loss polymer optical waveguides towards inter-chip and on-board optical interconnects at 850 nm. Taking advantage of coupling between quantum states in MQWs, the top polymer cladding and the bottom Au mirror form a Fabry–Pérot cavity to further enhance the EA of CMQWs, thereby greatly improving the extinction ratio (ER) at a low voltage. The device achieves an ER of ∼6 dB and an insertion loss (IL) <3 dB at 2 V, notably outperforming conventional surface-incident EA modulators at the same driving voltage. A further optimized modulator design can achieve a peak ER of 9–12 dB at 2 V with a low IL of 2–3 dB and a relatively broad spectral bandwidth of ∼10 nm. The low capacitance and reverse bias operation at a low voltage potentially offer ∼10× lower power consumption compared to direct modulation of 850 nm lasers. This simple surface-incident CMQW modulator is a promising candidate for integration with ultralow power inter-chip and on-board interconnect architectures.

Research paper thumbnail of Design of Hybrid Plasmonic Multi-Quantum-Well Electro-Reflective Modulators Towards <100 fJ/bit Photonic Links

IEEE Journal of Selected Topics in Quantum Electronics, 2020

Realization of on-board and inter-chip optical interconnects requires a photonic data link with p... more Realization of on-board and inter-chip optical interconnects requires a photonic data link with power consumption well below their electrical counterparts (i.e., <<1 pJ/bit). Currently, directly modulating 850 nm vertical cavity surface emitting lasers at >50 Gb/s requires 2–4 pJ/bit/channel. External reverse-biased modulators could drastically reduce this power consumption. Here we design ultralow power GaAs/AlGaAs multi quantum well electro-reflective modulators operating at 1 V for facile integration with polymer “optical bridges”, utilizing coupled quantum confined Stark effect between adjacent quantum wells and optical coupling to hybrid surface plasmon-slab modes for significantly enhanced extinction ratio and spectral bandwidth. Distinctive from conventional electro-optical or electro-absorption modulators, this new design synergistically leverages ultra-large changes in both refractive index (|Δn|∼0.05) and absorption coefficient (Δα∼104 cm−1), achieving 35-50 dB extinction ratio at 1 V reverse bias with a low insertion loss of 1–3 dB, an incident angle tolerance of ∼5°, and a spectral bandwidth of 7–10 nm. The modulator power consumption is ∼1.9 fJ/bit without the need of thermal tuning, and the RC-limited bandwidth well exceeds 100 GHz. This new modulator enables high bandwidth and ultralow power optical interconnect networks at >100 Gb/s/channel and <100 fJ/bit/channel compatible with ever-scaling CMOS technologies.

Research paper thumbnail of Optical Free-Form Couplers for High-density Integrated Photonics (OFFCHIP): A Universal Optical Interface

Journal of Lightwave Technology, 2020

Research paper thumbnail of Real-time, in situ probing of gamma radiation damage with packaged integrated photonic chips

Photonics Research, 2019

Integrated photonics is poised to become a mainstream solution for high-speed data communications... more Integrated photonics is poised to become a mainstream solution for high-speed data communications and sensing in harsh radiation environments, such as outer space, high-energy physics facilities, nuclear power plants, and test fusion reactors. Understanding the impact of radiation damage in optical materials and devices is thus a prerequisite to building radiation-hard photonic systems for these applications. In this paper, we report real-time, in situ analysis of radiation damage in integrated photonic devices. The devices, integrated with an optical fiber array package and a baseline-correction temperature sensor, can be remotely interrogated while exposed to ionizing radiation over a long period without compromising their structural and optical integrity. We also introduce a method to deconvolve the radiation damage responses from different constituent materials in a device. The approach was implemented to quantify gamma radiation damage and post-radiation relaxation behavior of ...

Research paper thumbnail of Low loss, flexible single-mode polymer photonics

Research paper thumbnail of High‐Efficiency All‐Dielectric Metalenses for Mid‐Infrared Imaging

Advanced Optical Materials, 2017

Research paper thumbnail of CMOS compatible fabrication of micro, nano convex silicon lens arrays by conformal chemical vapor deposition

Research paper thumbnail of Topologically patterning of polyvinyl alcohol microstructures for vertical-/hybrid-aligned nematic liquid-crystal gratings doped with polyhedral oligomeric silsesquioxane nanoparticles

Chinese Optics Letters, 2015

We demonstrate a soft lithography approach for fabrication of a topographically patterned polyvin... more We demonstrate a soft lithography approach for fabrication of a topographically patterned polyvinyl alcohol (PVA) liquid-crystal (LC) alignment layer. This specific approach employs modified micromolding in capillaries for negative replication of the PVA microstructures on indium tin oxide (ITO) substrates from patterned poly(dimethylsiloxane) molds in a single step, leading to planar alignment on the desired regions. By doping with polyhedral oligomeric silsesquioxane nanoparticles, which can induce vertical alignment on bare ITO surfaces, periodic LC phase gratings based on an alternating vertical-aligned/hybrid-aligned nematic geometry are presented as an application, and a theoretical model was used to simulate and examine the experimental results.

Research paper thumbnail of Effect of In Diffusion on the Property of Blue Light-Emitting Diodes

Chinese Physics Letters, 2015

In diffusion to blue light-emitting diode (LED) wafers is performed by the inductive coupled plas... more In diffusion to blue light-emitting diode (LED) wafers is performed by the inductive coupled plasma (ICP) treatment of a covering layer of indium tin oxide (ITO) on the wafer surface. The electrical property of the p-type contact is improved and the redshift of photoluminescence (PL) from the InGaN quantum well of the wafer is found. Measurements by x-ray photoelectron spectroscopy (XPS) demonstrate that In atoms have diffused into p-GaN. Reflectance spectra of the sample surface reveal the variation caused by the ICP treatment. A model of compensation of the in-plane strain of the InGaN layer is used to explain the redshift of the PL data. Finally, LEDs are fabricated by using as-grown and ICP-treated wafers and their properties are compared. Under an injection current of 20 mA, LEDs with ICP-induced In doping show a decrease of 0.3V in the forward voltage and an increase of 23% in the light output, respectively.

Research paper thumbnail of Rigorous microlens design using vector electromagnetic method combined with simulated annealing optimization

Optics express, Jan 19, 2014

In this paper, finite-aperture diffractive optical element with its critical dimension smaller th... more In this paper, finite-aperture diffractive optical element with its critical dimension smaller than illumination wavelength is modeled and optimized using an integrated method. This method employs rigorous analysis model based on Finite Difference Time Domain (FDTD), and simulated annealing (SA) global search algorithm. Numerical results reveal that the diffraction efficiency of the 8-step microlens quickly climbs to its global optimum along with the optimization process, which manifests its global search ability. The design algorithm and implementation are discussed in details. Considering its time consuming efficiency and global search ability, our method provides valuable reference value in practical multistep microlens design.

Research paper thumbnail of A flexible polymer waveguide platform with low-loss optical interfaces

2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), 2021

Single-mode polymer photonics is important to short-reach data communications, photonic packaging... more Single-mode polymer photonics is important to short-reach data communications, photonic packaging, sensing, and biophotonic light delivery. Mechanical flexibility and manufacturing scalability (e.g., roll-to-roll fabrication compatibility) are among other advantages often cited for these polymer materials. Here we report here experimental demonstration of mechanically flexible waveguides fabricated by using commercial off-the-shelf biocompatible polymers that claim a record low propagation loss of 0.11 dB/cm near 850 nm wavelength ( Fig. 1a ). In addition to their low optical loss, the waveguides also exhibit excellent mechanical flexibility and ruggedness, capable of withstanding over 1,000 bending cycles at 2 mm bending radius [1] .