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1550 nm

Animesh Bala, Kanan Roy Chowdhury, Md Borhan Mia, Mohammad Faisal
A triangular lattice dispersion compensating photonic crystal fiber is presented in this paper. The fiber produces high birefringence and operates at fundamental mode only. The full vector finite element method with a perfectly matched absorbing layer boundary condition is applied to investigate the guiding properties of the proposed fiber. The designed fiber demonstrates that it is possible to obtain a very large negative dispersion of -9486.1  ps/(nm·km) at 1550 nm wavelength with a negative dispersion more than -7000  ps/(nm·km) over the entire C-band (1530-1565 nm), which is suitable for broadband dispersion compensation...
September 1, 2017: Applied Optics
Donghai Niu, Shiqi Sun, Qiang Xu, Minghui Jiang, Xibin Wang, Zhiyong Li, Changming Chen, Yuanda Wu, Daming Zhang
In this paper, the power-consumption characteristics of a polymeric thermo-optic (TO) switch consisting of a silica under-cladding on silicon substrate, a polymer core surrounded with polymer upper-cladding, and aluminum heating electrodes with different widths were investigated. Norland optical adhesive 73 with a larger TO coefficient was selected as the core layer, which could reduce the power consumption effectively. The silica under-cladding, with large thermal conductivity, could shorten the response time...
July 20, 2017: Applied Optics
Mehdi Hassani Keleshtery, Hassan Kaatuzian, Ali Mir, Ashkan Zandi
We demonstrate the analogue of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) plasmonic waveguide. Plasmonic induced transparency is a method similar to EIT. In this paper, a plasmonic MDM waveguide is proposed by using an ellipse shaped side-coupled ring resonator and simulated by finite difference time domain. Plasmonics as a new field of chip-scale technology is an interesting substrate, which is used to propose and numerically investigate a novel MDM structure. The aforementioned framework is a 2×2 plasmonic ring resonator, employing gold as a metal and polymethyl methacrylate as a dielectric...
May 20, 2017: Applied Optics
Michael C Brupbacher, Dajie Zhang, William M Buchta, Marc B Airola, David M Brown, Michael E Thomas, James B Spicer
This study presents results for the high-temperature (up to 1550 K) optical properties of polycrystalline Cr-doped α-alumina materials. Diffuse reflectance spectra in the wavelength range of 510-840 nm are presented as a function of temperature to illustrate changes to the optical behavior of these materials including a previously unreported thermally activated splitting of the U-band absorption (A24→T24) in octahedrally coordinated Cr(3+). Measurements were made using a unique laser-based approach for high-temperature solid-state spectroscopy, involving front-side supercontinuum laser illumination and back-side CO2 laser heating...
September 20, 2017: Applied Optics
S Bhardwaj, K Mittholiya, A Bhatnagar, R Bernard, J A Dharmadhikari, D Mathur, A K Dharmadhikari
We describe two types of waveguides (type I and depressed cladding) inscribed in lithium niobate using a variable repetition rate (200 kHz-25 MHz), 270 fs duration fiber laser. The type I modification-based waveguides have propagation losses in the range from 1.2 to 10 dB/cm at 1550 nm, depending on experimental parameters. These waveguides are not permanent; they deteriorate over time. Such deterioration of waveguides can be slowed down from 30 days to 100 days by pre-annealing the samples and by writing at a 720 kHz laser repetition rate...
July 10, 2017: Applied Optics
Wanwan Liu, Yifu Chen, Xin Hu, Long Wen, Lin Jin, Qiang Su, Qin Chen
Non-metallic plasmonic materials have recently attracted research interest due to their adjustable plasmonic material properties and the potential low loss, which is important to plasmonic waveguides with ultrahigh mode confinement. In this paper, we analyzed the mode properties of four types of plasmonic waveguides based on noble metals, aluminum-zinc-oxide (AZO), and TiN, where the propagation length and mode size are chosen to compare the figures of merit. It is found that AZO has the smallest imaginary part of permittivity in the near-infrared region, while AZO waveguides have propagation lengths comparable to those of Cu waveguides but shorter than those of Au and Ag waveguides...
June 1, 2017: Applied Optics
Konstantin Gorbachenya, Viktor Kisel, Anatoly Yasukevich, Pavel Loiko, Xavier Mateos, Viktor Maltsev, Nikolai Leonyuk, Magdalena Aguiló, Francesc Díaz, Uwe Griebner, Valentin Petrov, Nikolai Kuleshov
A single-layer graphene saturable absorber is employed for passive Q-switching of an Er, Yb:GdAl3(BO3)4 (Er,Yb:GdAB) compact laser, representing the first Er-doped oxoborate laser Q-switched by graphene. This laser is based on a c-cut 1.8 at. % Er(3+), 15 at. % Yb(3+):GdAB crystal diode-pumped at 0.976 μm. It generates a maximum average output power of 360 mW at 1.55 μm with a slope efficiency of 23% (with respect to the incident power). Stable ∼1  μJ/130  ns pulses are achieved at a repetition rate of 400 kHz...
June 1, 2017: Applied Optics
Xiaobo Hu, Juanjuan Xue, Jiao Tian, Guoen Weng, Shaoqiang Chen
The effect of the Cu/Ga ratio on properties of deep-level defects in CuGaSe2 thin films were studied, using photocapacitance methods with two-wavelength excitation. The transient photocapacitance method, using a monochromatic probe light, determined two kinds of defects located at 0.8 eV and 1.5 eV above the valence band, respectively, the positions of which kept almost constant regardless of Cu/Ga ratio. In addition to the probe light, laser light with a wavelength of 1550 nm corresponding to 0.8 eV was then used to study the saturation effect of the deep-level defect at 0...
May 10, 2017: Applied Optics
Chia-Ti Wu, Chia-Chih Huang, Yeun-Chung Lee
In this paper, we propose a novel wavelength demultiplexer based on metal-insulator-metal plasmonic waveguides with a nanoscale ring resonator. Its transmission characteristics are numerically studied using finite element method (FEM) simulations, and the eigenwavelengths of the ring resonator are theoretically calculated. For the proposed structure, we found that the ratio of the orders of resonant transmittance peaks for two different high-order modes of the ring resonator is close to the ratio of the two communication wavelengths 1310 and 1550 nm...
May 10, 2017: Applied Optics
Yin-Jung Chang, Ren-Wei Feng
The theoretical formulation based on rigorous transmission-line networks is developed for a general mode conversion problem and lays the groundwork for a simpler yet more efficient graphical design approach for hybrid plasmonic mode converters (HPMCs). The concurrence of co- and cross-polarization conversion to and among higher-order photonic and HP modes followed by subsequent power redistributions and losses over the course of the HPMC can lead to performance degradation and largely determines the silicon core thickness...
July 1, 2017: Applied Optics
Zhengrui Tu, Dingshan Gao, Meiling Zhang, Daming Zhang
High-sensitivity complex refractive index sensing is proposed and experimentally demonstrated, favoring with sharp Fano resonance at 1550 nm wavelength based on subwavelength grating waveguide (SWG) micro-ring resonator. The micro-ring is composed by trapezoidal silicon pillars with subwavelength period to enhance the light-analyte overlap and get high quality factor as well. One straight SWG waveguide is side coupled with the micro-ring, which is specially designed to produce partial Fabry-Perot (FP) effect...
August 21, 2017: Optics Express
Hao Jia, Ting Zhou, Lei Zhang, Jianfeng Ding, Xin Fu, Lin Yang
We propose a 2 × 2 multimode optical switch, which is composed of two mode de-multiplexers, n 2 × 2 single-mode optical switches where n is the number of the supported spatial modes, and two mode multiplexers. As a proof of concept, asymmetric directional couplers are employed to construct the mode multiplexers and de-multiplexers, balanced Mach-Zehnder interferometer is utilized to construct the 2 × 2 single-mode optical switches. The fabricated silicon 2 × 2 multimode optical switch has a broad optical bandwidth and can support four spatial modes...
August 21, 2017: Optics Express
Kaijun Zhou, Qilai Zhao, Xiang Huang, Changsheng Yang, Can Li, Enbo Zhou, Xiaogeng Xu, Kenneth K Y Wong, Huihui Cheng, Jiulin Gan, Zhouming Feng, Mingying Peng, Zhongmin Yang, Shanhui Xu
A kHz-order linewidth controllable 1550 nm single-frequency fiber laser (SFFL) is demonstrated for the first time to our best knowledge. The control of the linewidth is realized by using a low-pass filtered white Gaussian noise (WGN) signal applied on a fiber stretcher in an optical feedback loop. Utilizing WGN signals with different signal amplitudes An and different cutoff frequencies fc, the linewidths are availably controlled in a wide range from 0.8 to 353 kHz. The obtained optical signal-to-noise ratio (OSNR) is more than 72...
August 21, 2017: Optics Express
Francesca Gallazzi, Giuseppe Rizzelli, Md Asif Iqbal, Mingming Tan, Paul Harper, Juan Diego Ania-Castañón
We experimentally evaluate the influence of RIN transfer from pump to signal on the transmission performance of a 10 × 30 Gbaud DP-QPSK transmission system using a 2nd-order ultra-long Raman fiber laser amplifier, considering the effect of cavity front-end reflectivity and forward pump power ratio. The evolution of the Q-factors with distance up to maximum reach is monitored for a 10 × 30 Gbaud DP-QPSK transmission system with WDM channels between 1542.94 nm to 1550.12 nm. A maximum transmission distance of 6479 km is found for configurations with low forward pump powers corresponding to the optimal balance between RIN and ASE impairments...
September 4, 2017: Optics Express
Fuchuan Lei, Yong Yang, Jonathan M Ward, Síle Nic Chormaic
A pump source is one of the essential prerequisites in order to achieve lasing in a system, and, in most cases, a stronger pump leads to higher laser power at the output. However, this behavior may be suppressed if two pump beams are used. In this work, we show that lasing around the 1600 nm band can be suppressed completely if two pumps, at wavelengths of 980 nm and 1550 nm, are applied simultaneously to an Yb:Er-doped microlaser, whereas it can be revived by switching one of them off. This phenomenon can be explained by assuming that the presence of one pump (980 nm) changes the role of the other pump (1550 nm); more specifically, the 1550 nm pump starts to consume the population inversion instead of increasing it when the 980 nm pump power exceeds a certain value...
October 2, 2017: Optics Express
Chenhao Wan, David Lombardo, Andrew Sarangan, Qiwen Zhan
We report the design, fabrication and characterization of a 1-by-5 geometric-phase polarization fan-out grating for coherent beam combining at 1550 nm. The phase profile of the grating is accurately controlled by the local orientation of the binary subwavelength structure instead of the etching depth and profile empowering the grating to be more tolerant to fabrication errors. Deep-UV interference lithography on silicon offers an inexpensive, highly efficient and high damage threshold solution to fabricating large-area fan-out gratings than electron beam lithography (EBL) and photoalignment liquid crystals...
October 2, 2017: Optics Express
Xiao Xu, Lin Ma, Shoulin Jiang, Zuyuan He
We demonstrate circular-core 1550 nm single-mode polymer waveguides with a graded-index profile fabricated by commercially available UV-curable epoxies using so-called mosquito method. The relative index difference ∆n of the waveguides was designed to be 0.46% in order to guarantee both single-mode operation and good compatibility with standard single-mode fiber. Accurate refractive index tuning of monomer for core construction was realized by mixing the core and cladding epoxies properly. The core pitch of the waveguides was chosen to be 50 μm to satisfy the requirements for high-density on-board optical interconnects...
October 16, 2017: Optics Express
A W Al-Alimi, N A Cholan, M H Yaacob, A F Abas, M T Alresheedi, M A Mahdi
A wide bandwidth and flat multiwavelength Brillouin-erbium fiber laser is demonstrated experimentally. In the proposed laser setup, the combination of a Brillouin mirror with feedback and a ring cavity with four-wave mixing assistance is realized. The efficiency of Brillouin Stokes lines generation is enhanced by the feedback-based Brillouin mirror structure. The effect of four-wave mixing in highly nonlinear fiber increases the generation of Brillouin Stokes lines in a wider bandwidth. The laser lines over 16 nm bandwidth (i...
August 7, 2017: Optics Express
Skyler Wheaton, Alireza Bonakdar, Iman Hassani Nia, Chee Leong Tan, Vala Fathipour, Hooman Mohseni
In the past two decades 3-D cameras have proven to be one of the next revolutions in machine vision. However, these devices are still an emerging technology with a particularly narrow set of commercially available devices. In this paper, the concept and execution of the first short wavelength infrared (SWIR) time-of-flight (ToF) 3-D camera system operating at a wavelength of 1550 nm is presented. By decoupling the optical and electrical components of the system in an open architecture we not only surpass many of the limitations of an on-chip integrated solution, but also can easily change the imaging device based on the requirements of the application...
August 7, 2017: Optics Express
Wei Wang, Yuan Dong, Shuh-Ying Lee, Wan-Khai Loke, Dian Lei, Soon-Fatt Yoon, Gengchiau Liang, Xiao Gong, Yee-Chia Yeo
The floating-base germanium-tin (Ge1-xSnx) heterojunction phototransistor (HPT) is designed and investigated as an efficient optical receiver in the short-wave infrared range. Simulations indicate that as the Sn content increases, the responsivity significantly increases due to a higher absorption coefficient and a larger valence band offset between Ge and Ge1-xSnx. Ge0.935Sn0.065 HPTs that incorporated high-quality Ge0.935Sn0.065 film grown by molecular beam epitaxy were fabricated, demonstrating optical response beyond wavelength of 2003 nm...
August 7, 2017: Optics Express
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