Read by QxMD icon Read

Optics Letters

Yueqing Du, Mengmeng Han, Peiyun Cheng, Xuewen Shu
We experimentally observed a novel pulsating soliton state with broadened Kelly sidebands in an ultrafast laser. Through simulations, we found that the synchronized and unsynchronized resonant dispersive waves coexisted in the laser. The incoherent interaction between the unsynchronized dispersive waves and soliton resulted in oscillation of the intensity and central wavelength of the soliton. The frequencies of the Kelly sidebands oscillated with the soliton, resulting in their spectral broadening when measured by an optical spectrum analyzer...
August 15, 2019: Optics Letters
Chenyang Wen, Fu Feng, Mindan Ren, Michael G Somekh, Ni Zhao, Shih-Chi Chen
In this Letter, we present a spatially resolved pump-probe microscope based on a digital micromirror device (DMD). The microscope system enables the measurements of ultrafast transient processes at arbitrarily selected regions in a 3-D specimen. To achieve random-access scanning, the wavefront of the probe beam is modulated by the DMD via binary holography. By switching the holograms stored in the DMD memory, the laser focus can be rapidly moved in space in a discrete fashion. The microscope system has a field of view of 65×130×155  μm3 in the x, y, and z axes, respectively; and a scanning speed of 8 kHz which is limited by the response time of the lock-in amplifier...
August 15, 2019: Optics Letters
Bo-Han Chen, Christina Hofer, Ioachim Pupeza, Peter Baum
Near-single-cycle mid-infrared pulses with a spectrum covering 5.4-11 μm are efficiently frequency-doubled in different GaSe crystals. The second-harmonic spectrum spans 3-4.3 μm at a power conversion efficiency of >20%. We measure an effective nonlinear coefficient of deff ≈35  pm/V. We also report on self-phase modulation and spectral broadening of the mid-infrared pulses in various bulk materials and find an increase of 45% of spectral width for 5 mm of Ge. These results demonstrate that nonlinear optical conversions can efficiently be driven by few-cycle mid-infrared radiation...
August 15, 2019: Optics Letters
Lin Chang, Andreas Boes, Paolo Pintus, Weiqiang Xie, Jon D Peters, M J Kennedy, Warren Jin, Xiao-Wen Guo, Su-Peng Yu, Scott B Papp, John E Bowers
In this Letter, we demonstrate a low loss gallium arsenide and aluminum gallium arsenide on an insulator platform by heterogenous integration. The resonators on this platform exhibit record high quality factors up to 1.5×106 , corresponding to a propagation loss ∼0.4  dB/cm. For the first time, to the best of our knowledge, the loss of integrated III-V semiconductor on insulator waveguides becomes comparable with that of the silicon-on-insulator waveguides. This Letter should have a significant impact on photonic integrated circuits (PICs) and become an essential building block for the evolving nonlinear PICs and integrated quantum photonic systems in the future...
August 15, 2019: Optics Letters
Lauren Guillemot, Pavel Loiko, Rémi Soulard, Alain Braud, Jean-Louis Doualan, Ammar Hideur, Richard Moncorgé, Patrice Camy
We report on novel upconversion (UC) pumping schemes for 2.3 μm thulium (Tm) lasers (the H4 3→H5 3 transition) based on a photon avalanche mechanism populating the intermediate metastable level (F4 3) acting as an effective ground state. The proposed pump wavelengths are ∼1 and ∼1.5  μm, each one corresponding to a resonant excited-state absorption transition F4 3→F2,3 3 and F4 3→H4 3, respectively. UC pumping at 1040, 1055, and 1451 nm of 2.3 μm Tm:LiYF4 lasers is demonstrated. In the former case, the laser generates 102 mW at 2302 nm with a slope efficiency of 14...
August 15, 2019: Optics Letters
Jiawei Luo, Zhenhua Wu, Daixuan Wu, Zhibing Liu, Xiaoming Wei, Yuecheng Shen, Zhaohui Li
In this Letter, we explore the effectiveness of a Hadamard encoding algorithm (HEA) for efficiently suppressing glare. Both numerical simulations and experimental data show that light intensity decays exponentially with respect to the number of HEA measurements. Specifically, we applied the HEA to reduce the intensity of a single speckle to 4.1% of its original value within only 16 measurements. In contrast, the commonly used genetic algorithm (GA) can reduce the speckle intensity only to 0.2 of its original value even after 1200 measurements...
August 15, 2019: Optics Letters
Wei Zhang, Yu Qin, Xinyi Xie, Zizhong Hu, Yannis M Paulus, Xinmai Yang, Xueding Wang
Photo-mediated ultrasound therapy (PUT) is a novel, noninvasive antimicrovascular approach that can treat neovascularization with high precision. We developed a photoacoustic (PA) sensing (PAS) system for PUT and achieved real-time PAS-guided PUT. Experiments performed on a chicken yolk sac membrane model demonstrated that PAS could monitor the treatment effect in a microvessel during PUT. Vessel shrinkage induced a decrease in the PA signal amplitude, while vessel rupture induced an abrupt increase in the PA signal amplitude...
August 15, 2019: Optics Letters
Amirhassan Shams-Ansari, Pawel Latawiec, Yoshitomo Okawachi, Vivek Venkataraman, Mengjie Yu, Boris Desiatov, Haig Atikian, Gary L Harris, Nathalie Picqué, Alexander L Gaeta, Marko Lončar
We experimentally demonstrate on-chip supercontinuum generation in the visible region in angle-etched diamond waveguides. We measure an output spectrum spanning 670-920 nm in a 5-mm-long waveguide using 100-fs pulses with 187 pJ of incident pulse energy. Our fabrication technique, combined with diamond's broad transparency window, offers a potential route toward broadband supercontinuum generation in the UV domain.
August 15, 2019: Optics Letters
Wenjuan Chen, Dan Zhu, Chenxu Xie, Jiang Liu, Shilong Pan
A microwave channelizer based on a photonic dual-output image-reject mixer (IRM) is proposed and demonstrated. By introducing the dual-output IRM based on the balanced Hartley structure, 2N channels can be produced by using the optical frequency combs (OFCs) with N comb lines. The required electrical hybrids and the optical filters are also reduced by half. In addition, the channelization efficiency is doubled, and the in-band interferences, including the image and the nonlinear mixing spurs, are greatly suppressed...
August 15, 2019: Optics Letters
Chenyu Yao, Qiang Wang, Yuechuan Lin, Wei Jin, Limin Xiao, Shoufei Gao, Yingying Wang, Pu Wang, Wei Ren
We demonstrate the first, to the best of our knowledge, photothermal carbon monoxide (CO) sensor using a hollow-core negative curvature fiber. The hollow-core fiber features a typical structure of one ring cladding containing eight nontouching capillaries to form a negative curvature core-surround. The photothermal effect in a 40-μm hollow core is induced by CO absorption at 2327 nm and detected by a Mach-Zehnder interferometer operating at 1533 nm. By using wavelength modulation spectroscopy, we achieve a normalized noise equivalent absorption coefficient of 4...
August 15, 2019: Optics Letters
C N Alexeyev, E V Barshak, B P Lapin, M A Yavorsky
In this Letter, we study the propagation of optical vortices (OVs) through the loop resonator (LR) on a multimode fiber. We demonstrate the existence of a special resonance, which is in the inversion of the topological charge of the transmitted OV. Near the resonance, the output orbital angular momentum (OAM) is sensitive to wavelength-scale variations of the LR's optical path length, which can be used for super-efficient OAM control. We also show the feasibility of a combined wavelength and OAM division multiplexing in comb filters on such LRs...
August 15, 2019: Optics Letters
Pablo Eugui, Danielle J Harper, Antonia Lichtenegger, Marco Augustin, Conrad W Merkle, Adelheid Woehrer, Christoph K Hitzenberger, Bernhard Baumann
We present a polarization-sensitive (PS) extension for bright- and dark-field (BRAD) optical coherence tomography imaging. Using a few-mode fiber detection scheme, the light backscattered at different angles is separated, and the BRAD images of tissue scattering are generated. A calibration method to correct for the fiber birefringence is proposed. Since particle scattering profiles are polarization dependent, a PS detection extends the capabilities for investigating the scattering properties of biological tissues...
August 15, 2019: Optics Letters
Karima Chah, Kivilcim Yüksel, Damien Kinet, Nazila Safari Yazd, Patrice Mégret, Christophe Caucheteur
Type-I fiber Bragg gratings photo-inscribed in hydrogen-loaded B/Ge co-doped silica single-mode optical fibers have been regenerated efficiently at 450°C, which is the lowest temperature reported so far. The mechanical strength of the annealed fiber is preserved while ensuring temperature sensing of the regenerated gratings up to 900°C. Unlike low temperature cycles (≤600°C), an annealing process at higher temperatures revealed faster regeneration for strong gratings. Changes in grating strength were also measured before the regeneration cycle...
August 15, 2019: Optics Letters
Ryoichi Horisaki, Yuka Okamoto, Jun Tanida
We present a method for single-shot three-dimensional imaging through scattering media with a three-dimensional memory effect. In the proposed computational process, a captured speckle image is two-dimensionally correlated with different scales, and the object is three-dimensionally recovered with three-dimensional phase retrieval. Our method was experimentally demonstrated with a lensless setup and was compared with a multishot approach used in our previous work [Opt. Lett.44, 2526 (2019)OPLEDP0146-959210...
August 15, 2019: Optics Letters
N Smijesh, X Zhang, P Fischer, A A Muschet, R Salh, A Tajalli, U Morgner, L Veisz
Temporal-intensity contrast is crucial in intense laser-matter interaction to circumvent the undesirable expansion of steep high-density plasma prior to the interaction with the main pulse. Nonlinear elliptical polarization rotation in an argon filled hollow-core fiber is used here for cleaning pedestals/satellite pulses of a chirped-pulse-amplifier based Ti:Sapphire laser. This source provides ∼35   μJ energy and sub-4-fs duration, and the process has >50 % internal efficiency, more than the most commonly used pulse cleaning methods...
August 15, 2019: Optics Letters
Bumjoon Jang, Julian Gargiulo, Ron Fatobene Ando, Alberto Lauri, Stefan A Maier, Markus A Schmidt
Efficient waveguiding inside low refractive index media is of key importance for a great variety of applications that demand strong light-matter interaction on small geometric footprints. Here, we demonstrate efficient light guidance in single-defect dual-ring light cages over millimeter distances that are integrated on silicon chips via direct laser writing. The cages consist of two rings of high aspect-ratio polymer strands (length 5 mm, aspect ratio >1000) hexagonally arranged around a hollow core. Clear-core mode formation via the photonic band gap effect is observed, with the experiments showing pronounced transmission bands with fringe and polarization contrasts of >20  dB and >15  dB, respectively...
August 15, 2019: Optics Letters
L A Herrera-Piad, M Delgado-Pinar, J L Cruz, A Carrascosa, A Díez, R Rojas-Laguna, M V Andrés
We propose the implementation of fiber Bragg gratings in tapered few-mode and multimode fibers to accomplish single-mode operation by reducing the core diameter, while preserving the core-cladding structure. The gratings present a single reflection band, and the device shows low insertion losses after the taper fabrication and the fiber Bragg gratings inscription. The excitation of high-order odd modes in the core of the fiber has been identified as the main loss mechanism; it can be prevented by means of symmetric illumination of the fibers...
August 15, 2019: Optics Letters
Lalit Singh, Sourabh Jain, Mukesh Kumar
An electrically writable resistive memory with optical readout based on silicon nanophotonic structure is proposed. Hybridization of optical and surface plasmonic modes in the device enables nanoscale optical confinement to efficiently detect the resistive memory effect in a 13 nm thick SiO2 layer sandwiched between p-type silicon and gold. Electrical write and optical readout capabilities of the proposed device are experimentally demonstrated with well-defined optical and electrical hysteresis curves at a wavelength of 1550 nm...
August 15, 2019: Optics Letters
Franco Gori, Massimo Santarsiero
Sources that exhibit superbunching in the spatial domain are discussed. A few model sources are presented with the pertaining probabilistic treatment. Schemes for the experimental realization of similar sources are suggested, and the results of simulated tests are given.
August 15, 2019: Optics Letters
Wenyan Zhang, Li Zhan, Tianhao Xian, Lirun Gao
Bidirectional mode-locked lasers are very useful in laser sensing and optical communications. Here we report a bidirectional domain wall soliton (DWS) fiber laser with an anomalous dispersion cavity. Two mode-locked dark pulse trains propagating in the opposite directions have been generated. Moreover, the specific application as a gyroscopic effect has been demonstrated by mounting this DWS laser on a rotating platform. The beat frequency of the two dark pulse DWS beams is measured as a linear function of the rotation velocity...
August 15, 2019: Optics Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"