The Experts below are selected from a list of 25395 Experts worldwide ranked by ideXlab platform

Kristinn B Gylfason - One of the best experts on this subject based on the ideXlab platform.

  • low power optical Beam Steering by microelectromechanical waveguide gratings
    Optics Letters, 2019
    Co-Authors: Carlos Errandoherranz, Nicolas Le Thomas, Kristinn B Gylfason
    Abstract:

    Optical Beam Steering is key for optical communications, laser mapping (lidar), and medical imaging. For these applications, integrated photonics is an enabling technology that can provide miniaturized, lighter, lower-cost, and more power-efficient systems. However, common integrated photonic devices are too power demanding. Here, we experimentally demonstrate, for the first time, to the best of our knowledge, Beam Steering by microelectromechanical (MEMS) actuation of a suspended silicon photonic waveguide grating. Our device shows up to 5.6° Beam Steering with 20 V actuation and power consumption below the μW level, i.e., more than five orders of magnitude lower power consumption than previous thermo-optic tuning methods. The novel combination of MEMS with integrated photonics presented in this work lays ground for the next generation of power-efficient optical Beam Steering systems.

  • low power optical Beam Steering by microelectromechanical waveguide gratings
    arXiv: Applied Physics, 2018
    Co-Authors: Carlos Errandoherranz, Nicolas Le Thomas, Kristinn B Gylfason
    Abstract:

    Optical Beam Steering is key for optical communications, laser mapping (LIDAR), and medical imaging. For these applications, integrated photonics is an enabling technology that can provide miniaturized, lighter, lower cost, and more power efficient systems. However, common integrated photonic devices are too power demanding. Here, we experimentally demonstrate, for the first time, Beam Steering by microelectromechanical (MEMS) actuation of a suspended silicon photonic waveguide grating. Our device shows up to 5.6° Beam Steering with 20 V actuation and a power consumption below the $\mu$W level, i.e. more than 5 orders of magnitude lower power consumption than previous thermo-optic tuning methods. The novel combination of MEMS with integrated photonics presented in this work lays ground for the next generation of power-efficient optical Beam Steering systems.

Chenwei Wei - One of the best experts on this subject based on the ideXlab platform.

  • Ultrafast Beam Steering using gradient Au- Ge_2Sb_2Te_5 -Au plasmonic resonators
    Optics express, 2015
    Co-Authors: Tun Cao, Guangzhao Zheng, Shuai Wang, Chenwei Wei
    Abstract:

    Beam Steering devices have gained extensive interests in the fields of optical interconnects, communications, displays and data storages. However, the challenge lies in obtaining an ultrafast Beam Steering structure in the optical regime. Here, we propose phase-array-like plasmonic resonators based on metal/phase-change materials (PCMs)/metal trilayers for all-optical ultrafast Beam Steering in the mid-infrared (MIR) region. We numerically demonstrate an angle Beam Steering of 11° for transmitted wave (front lobe) and 22° for reflected wave (back lobe) by switching between the amorphous and crystalline states of the PCM (Ge2Sb2Te5). A photothermal model is used to study the temporal variation of the temperature of the Ge2Sb2Te5 film to show potential for switching the phase of Ge2Sb2Te5 by optical heating. Generation of the Beam Steering in this structure exhibits a fast Beam Steering time of 3.6 ns under a low pump light intensity of 2.6 μW/μm2. Our design possesses a simple geometry which can be fabricated using standard photolithography patterning and is essential for exploiting the ultrafast Beam Steering in various applications in the MIR regime.

Juliet T. Gopinath - One of the best experts on this subject based on the ideXlab platform.

  • Nonmechanical Beam Steering using tunable lenses
    Conference on Lasers and Electro-Optics, 2017
    Co-Authors: Mo Zohrabi, Robert H. Cormack, Juliet T. Gopinath
    Abstract:

    We have used three tunable liquid lenses to demonstrate nonmechanical Beam Steering of ±75° using a fisheye lens, in two dimensions. The system can control the Beam divergence and provide two-dimensional Beam Steering.

  • Wide-angle nonmechanical Beam Steering using liquid lenses.
    Optics express, 2016
    Co-Authors: Mo Zohrabi, Robert H. Cormack, Juliet T. Gopinath
    Abstract:

    Nonmechanical Beam Steering is a rapidly growing branch of adaptive optics with applications such as light detection and ranging, imaging, optical communications, and atomic physics. Here, we present an innovative technique for one- and two-dimensional Beam Steering using multiple tunable liquid lenses. We use an approach in which one lens controls the spot divergence, and one to two decentered lenses act as prisms and steer the Beam. Continuous 1D Beam Steering was demonstrated, achieving Steering angles of ±39° using two tunable liquid lenses. The Beam scanning angle was further enhanced to ±75° using a fisheye lens. By adding a third tunable liquid lens, we achieved 2D Beam Steering of ±75°. In this approach, the divergence of the scanning Beam is controlled at all Steering angles.

Fumio Koyama - One of the best experts on this subject based on the ideXlab platform.

  • slow light vcsel amplifier for high resolution Beam Steering and high power operations
    Conference on Lasers and Electro-Optics, 2016
    Co-Authors: Masanori Nakahama, Akihiro Matsutani, Takahiro Sakaguchi, Fumio Koyama
    Abstract:

    We demonstrate the high-resolution Beam-Steering and amplification of novel VCSEL amplifiers, exhibiting Beam Steering of over 25° and sharp Beam divergence of 0.1°. The output power reaches at 29mW with a chip gain of 18dB.

  • Slow-light Bragg reflector waveguide array for two-dimensional Beam Steering
    Japanese Journal of Applied Physics, 2014
    Co-Authors: Kensuke Nakamura, Akihiro Matsutani, Moustafa Ahmed, Ahmed Bakry, Fumio Koyama
    Abstract:

    We propose and demonstrate a slow-light Bragg reflector waveguide array for two-dimensional (2D) Beam Steering. The device consists of a highly dispersive Bragg reflector waveguide array with a quarter-wavelength stack semiconductor mirrors and a Y-branch 1 × 4 splitter with a branching angle of 30°. The Beam Steering characteristics in the two orthogonal directions are clarified by tuning the input wavelength. Beam Steering was demonstrated using wavelength tuning with the assistance of delay sections. The results show the possibility of 2D Beam Steering using the Bragg reflector waveguide array by combining wavelength tuning and thermo-optic phase tuning.

  • Beam Steering, Beam Shaping, and Intensity Modulation Based on VCSEL Photonics
    IEEE Journal of Selected Topics in Quantum Electronics, 2013
    Co-Authors: Fumio Koyama
    Abstract:

    A Beam-Steering device has been a key element for various sensing and imaging applications. We proposed a Beam-Steering device based on a vertical-cavity surface-emitting laser (VCSEL)-based waveguide structure. We show a giant Steering angle and ultrahigh Steering resolution at the same time by increasing the length of a device. In this paper, we present our high-resolution Beam-Steering concept based on VCSEL photonics. A Steering angle of over 60° and a number of resolution points over 1000 are demonstrated for millimeter-scale devices, which is the highest in nonmechanical Beam-Steering devices. We also demonstrate the on-chip integration of a Beam-Steering function with a VCSEL. In addition, we demonstrate additional functionalities including the creation of vortex Beams and low-voltage amplitude modulation with Beam Steering.

  • Proposal of Beam Steering on slow-light waveguide amplifier
    2011
    Co-Authors: Toshikazu Shimada, Fumio Koyama
    Abstract:

    We propose a novel Beam Steering technique on slow-light waveguide amplifier. Giant Beam Steering is obtained with tuning operation wavelength. A possibility of high-resolution Beam Steering is suggested with increasing the amplifier length.

Irina Khromova - One of the best experts on this subject based on the ideXlab platform.

  • Ultrafast Beam Steering based on graphene metamaterial
    2017 11th European Conference on Antennas and Propagation (EUCAP), 2017
    Co-Authors: Bakhtiyar Orazbayev, Miguel Beruete, Irina Khromova
    Abstract:

    In this work we demonstrate three different designs of tunable mid-infrared (MIR) Beam Steering devices based on multilayer graphene-dielectric metamaterials. In all designs the tunable Beam Steering is achieved by controlling the effective refractive index of the graphene metamaterial, which is done by changing the chemical potential of each graphene layer. The proposed Beam steerer concepts allow a wide range of output angles (up to approximately 70 deg) and low reflection losses. The graphene-based tunable Beam Steering can be used in tunable transmitter/receiver modules for infrared imaging and sensing.

  • Tunable Beam Steering enabled by graphene metamaterials.
    Optics express, 2016
    Co-Authors: Bakhtiyar Orazbayev, Miguel Beruete, Irina Khromova
    Abstract:

    We demonstrate tunable mid-infrared (MIR) Beam Steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential of each graphene layer. This can arbitrarily tailor the spatial distribution of the phase of the transmitted Beam, providing mechanisms for active Beam Steering. Three different Beam steerer (BS) designs are discussed: a graded-index (GRIN) graphene-based metamaterial block, an array of metallic waveguides filled with graphene-dielectric metamaterial and an array of planar waveguides created in a graphene-dielectric metamaterial block with a specific spatial profile of graphene sheets doping. The performances of the BSs are numerically analyzed, showing the tunability of the proposed designs for a wide range of output angles (up to approximately 70°). The proposed graphene-based tunable Beam Steering can be used in tunable transmitter/receiver modules for infrared imaging and sensing.

  • Graphene-dielectric metamaterial for Beam Steering
    2016 10th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics (METAMATERIALS), 2016
    Co-Authors: Bakhtiyar Orazbayev, Miguel Beruete, Irina Khromova
    Abstract:

    This work presents the designs of tunable mid-infrared (MIR) Beam Steering devices based on multilayer graphene-dielectric metamaterials. A tunable Beam Steering is achieved by changing the chemical potential of each graphene layer and, therefore, the effective refractive index of the metamaterial. Three different Beam steerer concepts with a wide range of output angles (up to approximately 70°) are discussed. The proposed graphene-based tunable Beam Steering can be used in tunable transmitter/receiver modules for infrared imaging and sensing.