Read by QxMD icon Read

Optics Letters

Hong Zhao, Chunwei Zhang, Changquan Zhou, Kejian Jiang, Meiqi Fang
In this erratum, an error in Eq. (14) in our recently published Letter [Opt. Lett.41, 4951 (2016)10.1364/OL.41.004951OPLEDP0146-9592] is corrected.
January 15, 2017: Optics Letters
Jun Xin, Jian Qi, Jietai Jing
A maximal joint quadrature squeezing of -6.8±0.4  dB is experimentally obtained by a scheme of cascaded four-wave mixing (FWM) processes, which gives strong proof about the inseparability or entanglement between output of the twin beams from the system. Here joint quadrature is the difference between the two quadratures of the twin beam output from the cascaded FWM processes. This result is enhanced by about 3.1 dB, compared with the one of the single FWM process. We also study the gain dependence of the entanglement enhancement in this cascaded system...
January 15, 2017: Optics Letters
Ugo Tricoli, Callum M Macdonald, Anabela Da Silva, Vadim A Markel
We derive a reciprocity relation for the 3D vector radiative transport equation that describes propagation of polarized light in multiple-scattering media. We then show how this result, together with translational invariance of a plane-parallel sample, can be used to efficiently compute the sensitivity kernel of diffuse optical tomography by Monte Carlo simulations. Numerical examples of polarization-selective sensitivity kernels are given.
January 15, 2017: Optics Letters
Zhong-Mei Huang, Wei-Qi Huang, Zui-Min Jiang, Shi-Rong Liu, Xue-Ke Wu, Chao-Jian Qin
It is found that the optimum annealing temperature is about 1000°C for the infrared emission of defect states at room temperature on black silicon (BS) prepared by using a nanosecond-pulsed laser. In addition, it is observed that the suitable annealing time is 6∼8  min at 1000°C for the emission on the BS. The crystallizing proceeding in annealing on the BS can be used to explain the above annealing effect. It is interesting that the emission band becomes intensive and broader on the BS prepared in oxygen atmosphere than that prepared in vacuum in the analysis of photoluminescence spectra, where the electronic states localized at the defects from D1 to D4 doped with oxygen play an important role in the emission with the broader band which are obviously enhanced in the room temperature...
January 15, 2017: Optics Letters
Olivier Emile, Janine Emile
Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved...
January 15, 2017: Optics Letters
Tobias Meinert, Benjamin Alexander Gutwein, Alexander Rohrbach
Light-sheet microscopy enables fast 3D, high-contrast imaging in biology and colloidal sciences. Recently, the controlled transport of living embryos or small colloids through stable glass capillaries is manifold interesting. Although they hardly impair the sample, glass capillaries spoil the image by generating significant aberrations of the illumination and detection light. Here, we analyze the deflection of illuminating Bessel beams at the capillary by k-spectral shifting, and correct for it by a beam deflector...
January 15, 2017: Optics Letters
Po-Hao Wang, Vijay Raj Singh, Jau-Min Wong, Kung-Bin Sung, Yuan Luo
Confocal imaging techniques offer an optical sectioning capability to acquire three-dimensional information from various volumetric samples by discriminating the desired in-focus signals from the out-of-focus background. However, confocal, in general, requires a point-by-point scan in both the lateral and axial directions to reconstruct three-dimensional images. In addition, axial scanning in confocal is slower than scanning in lateral directions. In this Letter, a non-axial-scanning multifocal confocal microscope incorporating multiplexed holographic gratings in illumination and dual detection for depth discrimination is presented...
January 15, 2017: Optics Letters
Daniele Melati, Andrea Alippi, Andrea Annoni, Nicola Peserico, Andrea Melloni
A photonic integrated circuit performing simultaneous mode and wavelength demultiplexing for few-mode-fiber transmission is demonstrated for the first time. The circuit is realized on an InP-based technological platform; it can handle up to eight mode- and wavelength-division-multiplexed (MDM/WDM) channels and allows all-optical multiple-input-multiple-output processing to unscramble mode mixing generated by fiber propagation. A single arrayed waveguide grating is used to demultiplex the WDM channels carried by all the propagating modes, optimizing circuit complexity, chip area, and operational stability...
January 15, 2017: Optics Letters
Alan Y Liu, Jon Peters, Xue Huang, Daehwan Jung, Justin Norman, Minjoo L Lee, Arthur C Gossard, John E Bowers
We demonstrate the first electrically pumped continuous-wave (CW) III-V semiconductor lasers epitaxially grown on on-axis (001) silicon substrates without offcut or germanium layers, using InAs/GaAs quantum dots as the active region and an intermediate GaP buffer between the silicon and device layers. Broad-area lasers with uncoated facets achieve room-temperature lasing with threshold current densities around 860  A/cm<sup>2</sup> and 110 mW of single-facet output power for the same device...
January 15, 2017: Optics Letters
Chao Li, Min Wang, Jun-Fang Wu
Fano resonance is widely used to realize high-contrast nonreciprocal transmission. However, resonance-enhanced all-optical diodes (AOD) are bandwidth-limited, and their transmission rates are normally low, which restricts realistic application. In this Letter, we analytically and numerically demonstrate that this limitation can be overcome once multistability of cascaded nonlinear cavities is appropriately excited. By precisely molding the transiting of the signal light between multistable states, a high-contrast-ratio, high-unidirectional-transmission-rate, and reversal-controllable AOD is achieved with a bandwidth over 2...
January 15, 2017: Optics Letters
Meng Liu, Ai-Ping Luo, Zhi-Chao Luo, Wen-Cheng Xu
Ultrafast fiber laser, as a dissipative nonlinear optical system, plays an important role in investigating various nonlinear phenomena and soliton dynamics. Vector features of solitons, including polarization locked and polarization rotation vector solitons (PRVSs), are interesting nonlinear dynamics in ultrafast fiber lasers. Herein, we experimentally reveal the trapping characteristics of PRVSs for the first time, to the best of our best knowledge. We show that, for the conventional soliton trapping in the ultrafast fiber laser, the soliton central wavelengths of the two polarization components are constant at the laser output port...
January 15, 2017: Optics Letters
Hartmut Liebetrau, Marco Hornung, Sebastian Keppler, Marco Hellwing, Alexander Kessler, Frank Schorcht, Joachim Hein, Malte C Kaluza
We present pulse stretching with an intracavity Offner-type pulse stretcher applied to a high-energy, short-pulse laser system. The compact intracavity design, offering a tunable stretching factor, allows the pulses to be stretched to several nanoseconds and, at the same time, to be amplified to 100 μJ. The stretched pulses have been further amplified with the high-power laser system Polaris and have been recompressed to durations as short as 102 fs, reaching peak powers of 100 TW. Furthermore, the temporal intensity contrast is investigated and compared to the formerly used stretcher setup...
January 15, 2017: Optics Letters
Haiting Xia, Silvio Montresor, Rongxin Guo, Junchang Li, François Olchewsky, Jean-Michel Desse, Pascal Picart
This Letter proposes a robust processing of phase dislocations to recover continuous phase maps. The approach is based on combined unwrapping and inpainting methods. Phase dislocations are determined using an estimator based on the second order phase gradient. The algorithm is validated using a realistic simulation of phase dislocations, and the phase restoration exhibits only weak errors. A comparison with other inpainting algorithms is also provided, demonstrating the suitability of the approach. The approach is applied to experimental data from off-axis digital holographic interferometry...
January 15, 2017: Optics Letters
Kathrin J Mohler, Bernhard J Bohn, Ming Yan, Gwénaëlle Mélen, Theodor W Hänsch, Nathalie Picqué
We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstrate a spectra of liquids, which span 1100  cm<sup>-1</sup> of Raman shifts. At a resolution of 6  cm<sup>-1</sup>, their measurement time may be as short as 5 μs for a refresh rate of 2 kHz. The waiting period between acquisitions is improved 10-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies...
January 15, 2017: Optics Letters
Svetlana A Malinovskaya
Quantum control methodology is presented to design many-body spin states in a spin chain of Rydberg atoms using laser pulses and a magnetic field. A two-photon ladder-type configuration is implemented, which is advantageous due to the combined action of the one-photon and two-photon detunings as control parameters. Many-body spin states are designed consisting of an ensemble of spins encoded in sublevels of Rydberg states and coupled via the van der Waals interactions.
January 15, 2017: Optics Letters
Aniceto Belmonte
Field conjugation arrays use adaptive combining techniques on multi-aperture receivers to improve the performance of coherent laser communication links by mitigating the consequences of atmospheric turbulence on the down-converted coherent power. However, this motivates the use of complex receivers as optical signals collected by different apertures need to be adaptively processed, co-phased, and scaled before they are combined. Here, we show that multiple apertures, coupled with optical delay lines, combine retarded versions of a signal at a single coherent receiver, which uses digital equalization to obtain diversity gain against atmospheric fading...
January 15, 2017: Optics Letters
Émeric Mercier, Lionel Weicker, Delphine Wolfersberger, Deborah M Kane, Marc Sciamanna
We experimentally report the sequence of bifurcations destabilizing and restabilizing a laser diode with phase-conjugate feedback when the feedback rate is increased. Specifically, we successively observe the initial steady state, undamped relaxation oscillations, quasi-periodicity, chaos, and oscillating solutions at harmonics up to 13 times the external cavity frequency but also the restabilization to a steady state. The experimental results are qualitatively well reproduced by a model that accounts for the time the light takes to penetrate the phase-conjugate mirror...
January 15, 2017: Optics Letters
C L Sung, C Y Lee, C C Chang, H C Liang, Y F Chen
The reflectivity of the output coupler is designed to achieve the synchronously self-mode-locked operation at 1064 and 1123 nm in a diode-end-pumped Nd:YAG laser. Numerical analyses are performed to confirm that the designed output coupler can lead the emission lines to be predominant at 1064 and 1123 nm. Moreover, the crossover of the threshold pump powers for the 1064 and 1123 nm emission lines can be exploited to obtain the single central wavelength of 1064 nm or the single central wavelength of 1123 nm or, simultaneously, dual-central-wavelength self-mode-locked operation by finely adjusting the cavity alignment...
January 15, 2017: Optics Letters
B Hafizi, J R Peñano, J P Palastro, R P Fischer, G DiComo
A high-power laser beam propagating through a dielectric in the presence of fluctuations is subject to diffraction, dissipation, and optical Kerr nonlinearity. A method of moments was applied to a stochastic, nonlinear enveloped wave equation to analyze the evolution of the long-term spot radius. For propagation in atmospheric turbulence described by a Kolmogorov-von Kármán spectral density, the analysis was benchmarked against field experiments in the low-power limit and compared with simulation results in the high-power regime...
January 15, 2017: Optics Letters
Xavier Audier, Naveen Balla, Hervé Rigneault
We demonstrate femtosecond pump-probe transient absorption spectroscopy using a programmable dispersive filter as an ultra-fast delay line. Combined with fast synchronous detection, this delay line allows for recording of 6 ps decay traces at 34 kHz. With such acquisition speed, we perform single point pump-probe spectroscopy on bulk samples in 80 μs and hyperspectral pump-probe imaging over a field of view of 100 μm in less than a second. The usability of the method is illustrated in a showcase experiment to image and discriminate between two pigments in a mixture...
January 15, 2017: 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"