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Optics Express

Yusuke Kohno, Kento Komatsu, Rui Tang, Yasuyuki Ozeki, Yoshiaki Nakano, Takuo Tanemura
We experimentally demonstrate the use of a large-scale silicon-photonic optical phased array (OPA) chip as a compact, low-cost, and potentially high-speed light illuminating device for ghost imaging (GI) applications. By driving 128 phase shifters of a newly developed silicon OPA chip using rapidly changing random electrical signals, we successfully retrieve a slit pattern with over 90 resolvable points in one dimension. We then demonstrate 2D imaging capability by sweeping the wavelength. With the potential of integrating high-speed phase modulators, tunable lasers, grating couplers, and CMOS driver circuit on the same silicon platform, this work paves the way towards realizing ultrahigh-speed and low-cost single-chip GI devices...
February 4, 2019: Optics Express
Wenxiao Wang, Fan Ye, Hao Shen, Nicholas A Moringo, Chayan Dutta, Jacob T Robinson, Christy F Landes
Point spread function (PSF) engineering by phase modulation is a novel approach to three-dimensional (3D) super-resolution microscopy, with different point spread functions being proposed for specific applications. It is often not easy to achieve the desired shape of engineered point spread functions because it is challenging to determine the correct phase mask. Additionally, a phase mask can either encode 3D space information or additional time information, but not both simultaneously. A robust algorithm for recovering a phase mask to generate arbitrary point spread functions is needed...
February 4, 2019: Optics Express
Yongyao Xie, Zhaojun Liu, Zhenhua Cong, Zengguang Qin, Shang Wang, Zhixu Jia, Chengzhi Li, Guanshi Qin, Xibao Gao, Xingyu Zhang
A Yb:YAG-derived silica fiber was fabricated by a molten-core fabrication method, in which a Yb:YAG crystal was used as the core material and a silica tube was used as the cladding material. The fiber's transmission loss was measured to be 0.49 dB/m at 1.55 µm, using a cut-back method. The fiber microstructure image showed that the cladding region was a uniform glass structure, while the core structure was amorphous. An all-fiber-integrated cladding-pumped laser based on Yb:YAG-derived silica fiber was demonstrated...
February 4, 2019: Optics Express
Moritz Matthiae, Anders Kristensen
Spatially offset Raman spectroscopy (SORS) enables one to distinguish chemical fingerprints of top and subsurface layers. In this paper, we apply SORS to a microfluidic two-layer system consisting of transparent liquid in a microchannel as the surface layer and microfluidic PDMS chip material as the sublayer. By using an imaging spectrograph connected to a microscope, we perform hyperspectral SORS acquisitions. Furthermore, the focus position z is translated. Thus, we combine the two methods of hyperspectral SORS and defocusing micro-SORS, which leads to an integral characterization of the layered system...
February 4, 2019: Optics Express
Chadwick L Canedy, William W Bewley, Charles D Merritt, Chul Soo Kim, Mijin Kim, Michael V Warren, Eric M Jackson, Jill A Nolde, C A Affouda, Edward H Aifer, Igor Vurgaftman, Jerry R Meyer
We report resonant-cavity infrared detectors with 34% external quantum efficiency at room temperature at the resonant wavelength of 4.0 μm, even though the absorber consists of only five quantum wells with a total thickness of 50 nm. The full width at half maximum (FWHM) linewidth is 46 nm, and the peak absorption is enhanced by nearly a factor of 30 over that for a single pass through the absorber. In spite of an unfavorable Shockley-Read lifetime in the current material, the dark current density is at the level of state-of-the-art HgCdTe detectors as quantified by "Rule 07...
February 4, 2019: Optics Express
Zi-Yu Chen, Rui Qin
Circularly polarized extreme ultraviolet (XUV) radiation is highly interesting for investigation of chirality-sensitive light-matter interactions. Recent breakthroughs have enabled the generation of such light sources via high harmonic generation (HHG) from rare gases. There is a growing interest in extending HHG medium from gases to solids, especially to 2D materials, as they hold great promise to develop ultra-compact solid-state photonic devices and provide insights into electronic properties of the materials themselves...
February 4, 2019: Optics Express
Haifei Hu, Xiao Luo, Zhenyu Liu, Xuejun Zhang, Donglin Xue, Hongwei Zhao
In order to improve the fabrication efficiency and testing accuracy of meter-scale, large monolithic mirrors, hydraulic support units (HSUs) are commonly used. However, the challenges to reduce the disparity of the HSUs' stiffness and keep the stability of the mirrors' altitude are hard to resolve, especially for large-scale mirrors. In this paper, we found the air ratio of the working fluid for HSUs is a key factor for designing the HSUs to resolve the challenges from the analytical solution that we derived for supporting large mirrors...
February 4, 2019: Optics Express
Zibang Zhang, Zijian Su, Qiwen Deng, Jiaquan Ye, Junzheng Peng, Jingang Zhong
Single-pixel imaging commonly uses a spatial light modulator (SLM) to encode a scene's spatial information into a one-dimensional light signal sequence so that a single-pixel detector can be used to capture a scene. Digital micromirror device, liquid crystal on silicon, or light emitted diode matrix is a common choice of SLM, but it requires a certain lens system in order to project the structured light pattern that is generated by the SLM onto the scene. Using a lens would not only lead to aberration but also result in difficulty for establishing a compact imaging system...
February 4, 2019: Optics Express
Seyed Ehsan Jamali Mahabadi, Shaokang Wang, Thomas F Carruthers, Curtis R Menyuk, Franklyn J Quinlan, Meredith N Hutchinson, Jason D McKinney, Keith J Williams
We describe a procedure to calculate the impulse response and phase noise of high-current photodetectors using the drift-diffusion equations while avoiding computationally expensive Monte Carlo simulations. We apply this procedure to a modified uni-traveling-carrier (MUTC) photodetector. In our approach, we first use the full drift-diffusion equations to calculate the steady-state photodetector parameters. We then perturb the generation rate as a function of time to calculate the impulse response. We next calculate the fundamental shot noise limit and cut-off frequency of the device...
February 4, 2019: Optics Express
Ronan Gourgues, Iman Esmaeil Zadeh, Ali W Elshaari, Gabriele Bulgarini, Johannes W N Los, Julien Zichi, Dan Dalacu, Philip J Poole, Sander N Dorenbos, Val Zwiller
Integration of superconducting nanowire single-photon detectors and quantum sources with photonic waveguides is crucial for realizing advanced quantum integrated circuits. However, scalability is hindered by stringent requirements on high-performance detectors. Here we overcome the yield limitation by controlled coupling of photonic channels to pre-selected detectors based on measuring critical current, timing resolution, and detection efficiency. As a proof of concept of our approach, we demonstrate a hybrid on-chip full-transceiver consisting of a deterministically integrated detector coupled to a selected nanowire quantum dot through a filtering circuit made of a silicon nitride waveguide and a ring resonator filter, delivering 100 dB suppression of the excitation laser...
February 4, 2019: Optics Express
Fang Hou, Muyang Zhang, Yinbo Zheng, Lei Ding, Xiaodong Tang, Yanmei Liang
An approach to characterize laser-induced bulk damage in optical crystal materials was demonstrated. With a homemade swept-source optical coherence tomography (SS-OCT) system, we obtained three-dimensional images of the bulk damage produced by laser pulses with wavelength of 351 nm, pulse width of 5 ns, beam diameter of 5.5 mm and fluences from 4.56 J/cm2 to 9.95 J/cm2 in Potassium Dihydrogen Phosphate (KDP) crystal. Algorithms based on three-dimensional OCT images were specially designed to count and locate bulk damage pinpoints in KDP crystal, obtaining their equivalent diameter distribution and pinpoint density caused by different fluences...
February 4, 2019: Optics Express
Cheng Chen, Jian Wang, Richard Leach, Wenlong Lu, Xiaojun Liu, Xiangqian Jane Jiang
Accurate and reliable peak extraction of axial response signals plays a critical role in confocal microscopy. For axial response signal processing, nonlinear fitting algorithms, such as parabolic, Gaussian or sinc2 fitting may cause significant systematic peak extraction errors. Also, existing error compensation methods require a priori knowledge of the full-width-at-half-maximum of the axial response signal, which can be difficult to obtain in practice. In this paper, we propose a generalised error compensation method for peak extraction from axial response signals...
February 4, 2019: Optics Express
G V Odintsova, E A Vlasova, Y M Andreeva, M K Moskvin, A S Krivonosov, E V Gorbunova, D V Pankin, O S Medvedev, M M Sergeev, N N Shchedrina, D S Lutoshina, V P Veiko
We offer to use optical features of surface plasmon resonance in Ag nanoparticles for jewelry application as a method for the well-controlled decoration of silver items. The novel approach of silver nanoparticles formation with sizes from 5 to 50 nm via nanosecond direct laser writing allows for controlling the reflectance spectra, thus creating a color image on precious metals with a high resolution of about 450 dpi without dyes or hazardous chemicals. Moreover, the large-scale color image can be applied in single-step processing with significant productivity of 2 cm2 per minute...
February 4, 2019: Optics Express
Quan Yuan, Feng Wang, Tao Liu, Yu Liu, Yixin Zhang, Zhen Zhong, Xuping Zhang
The frequency-drift of laser source is a crucial factor for influencing the performance of the phase-sensitive optical time domain reflectometer (Φ-OTDR). It induces signal fluctuation and severely limits the measurement capacity for low frequency. In this paper, a twice differential method is proposed to compensate for the influence of the laser-frequency-drift in Φ-OTDR. It uses the differential signal between two points on the sensing fiber as a reference signal and then subtracts the reference signal from the main signal to obtain the final result...
February 4, 2019: Optics Express
Weiqiang Xie, Tin Komljenovic, Jinxi Huang, Minh Tran, Michael Davenport, Alfredo Torres, Paolo Pintus, John Bowers
Heterogeneous silicon photonics is uniquely positioned to address the photonic sensing needs of upcoming autonomous cars and provide the necessary cost reduction for widespread deployment. This is because it allows for wafer-scale active/passive integration, including optical sources. We present our recent research and the development of interferometric optical gyroscopes and LiDAR sensors. More specifically, we show a fully integrated gyroscope front-end occupying an area of only 4.5 mm2 . We also show the first dense pitch optical phased array using heterogeneous phase shifters...
February 4, 2019: Optics Express
Fei Liu, Yi Wei, Pingli Han, Kui Yang, Lu Bai, Xiaoepeng Shao
Underwater imaging provides human vision system friendly images; however, it often suffers from severe image degradation. This research developed an underwater polarization imaging model, which considers the water scattering effect, as well as absorption effect. It fully explored the polarization information of the target scene that backscattered light is partially polarized and target light is unpolarized. Then backscattered light is first estimated and removed. The target scene's distance information is derived based upon the polarization information, and then applied to develop a distance-based Lambertian model...
February 4, 2019: Optics Express
Abebe T Tarekegne, Binbin Zhou, Korbinian Kaltenecker, Krzysztof Iwaszczuk, Stewart Clark, Peter Uhd Jepsen
We investigate the dielectric properties of the 4H and 6H polytypes of silicon carbide in the 0.1-19 THz range, below the fundamental transverse-optical phonons. Folding of the Brillouin zone due to the specific superlattice structure of the two polytypes leads to activation of acoustic phonon modes. We use a combination of ultrabroadband terahertz time-domain spectroscopy and simulations based on density-functional perturbation theory to observe and characterize these modes, including band splitting due to the dissimilar carbon and silicon sublattices of the structures, and an indirect measurement of the anisotropic sound velocities in the two polytypes...
February 4, 2019: Optics Express
Stella Civelli, Sergei K Turitsyn, Marco Secondini, Jaroslaw E Prilepsky
We correct a formula for the numerical nonlinear Fourier transform in [1]. The conclusions of our work are unchanged.
February 4, 2019: Optics Express
Peipeng Xu, Jiajiu Zheng, Jun Zhou, Yueyang Chen, Chen Zou, Arka Majumdar
We present the design, fabrication, and characterization of a multi-slot photonic crystal (PhC) cavity sensor on the silicon-on-insulator platform. By optimizing the structure of the PhC cavity, most of the light can be distributed in the lower index region; thus, the sensitivity can be dramatically improved. By exposing the cavities to different mass concentrations of NaCl solutions, we obtained that the wavelength shift per refractive index unit (RIU) for the sensor is 586 nm/RIU, which is one of the highest sensitivities achieved in a non-suspended cavity...
February 4, 2019: Optics Express
Baihui Zhang, Hongjian Li, Hui Xu, Mingzhuo Zhao, Cuixiu Xiong, Chao Liu, Kuan Wu
We propose a novel simple patterned monolayer graphene metamaterial structure based on tunable terahertz plasmon-induced transparency (PIT). Destructive interference in this structure causes pronounced PIT phenomenon, and the PIT response can be dynamically controlled by voltage since the existence of continuous graphene bands in the structural design. The theoretical transmission of this structure is calculated by coupled mode theory (CMT), and the results are highly consistent with the simulation curve. After that, the influence of the graphene mobility on the PIT response and absorption characteristics is researched...
February 4, 2019: Optics Express
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