A problem often encountered in wave physics concerns the interaction of various types waves, and energy transfer from one to another. In particular case waves same nature, "modes" can be distinguished such a way that represented as sum these modes. Their essential character is associated with each does not vary time. It also said modes are "coupled." This, for instance, guided an electric waveguide, mechanical vibration bar, levels quantum physics.

The unique performances attached to the heterodyne (or coherent) optical detection process can be fully exploited with single-mode fiber transmission. Strong improvement over direct is expected in terms of bit error rate (BER) or repeater spacing, especially for 1.6 μm operation. requirements such a system are reviewed and interpreted individual components design. emission frequency stability laser diodes, ability cables maintain polarization, availability light amplifiers found most...

Gain, polarization sensitivity, saturation power, and noise characteristics of quaternary semiconductor laser amplifiers the Fabry-Perot (FP) traveling-wave (TW) types are reviewed. The status antireflection coatings for TW is presented. New results concerning sensitivity output power a 1.5-μm buried-heterostructure (BH) amplifier reported. A theoretical model presented influence waveguide structure on maximum internal gain CW-operating 1.5- μm BH amplifier, including thermal effects,...

A 1.26 μm optical amplifier with a facet modal reflectivity below 0.0001 has been used in 58 mm-long grating external cavity. The lasing wavelength continuously tuned without mode hopping over range of 15 nm by combined translation-rotation the diffraction grating. linewidth 20 kHz derived from heterodyne beat frequency measurements between two tunable external-cavity lasers.

Signal transmission experiments were performed at 170 Gbit/s in an integrated Al 2 O 3 :Er 3+ waveguide amplifier to investigate its potential application high-speed photonic circuits.Net internal gain of up 11 dB was measured for a continuous-wave 1532 nm signal under 1480 pumping, with threshold pump power 4 mW.A differential group delay ps between the TE and TM fundamental modes 5.7-cm-long measured.When selecting single polarization open eye diagrams bit error rates equal those system...

Spectral measurements are employed in many precision agriculture applications, due to their ability monitor the vegetation's health state. vegetation indices one of main techniques currently used remote sensing activities, since they related biophysical and biochemical crop variables. Moreover, have been evaluated some studies as potentially beneficial for detecting or differentiating diseases. Flavescence Dorée (FD) is an infectious, incurable disease grapevine that can produce severe yield...

This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed randomly distributed objects with spatial discontinuities. In agronomic sciences, scene is difficult due nature scenes. Our based on Shape from Focus technique initially used in microscopic domain. We propose adapt this macroscopic domain and we detail as well processing perform such technique. The monocular passive method that resolves occlusion problem affecting multi-cameras...

Disease detection and control is one of the main objectives vineyard research in France. Manual monitoring diseases a time consuming operation especially when fields are large. Current studies aim to develop automatic in-field systems detect diseases. This study investigated optimal spectral bands for design dedicated high-resolution multispectral camera embedded on an unmanned aerial vehicle identifying infected zones grapevine field. The target disease was Flavescence dorée, which...

We investigate transmitter IQ imbalance compensation based on the blind adaptive source separation (BASS) method in a dual-polarization M-QAM optical coherent system. The robustness of BASS against residual carrier frequency offset (CFO) is numerically investigated and compared to that Gram–Schmidt orthogonalization procedure (GSOP). further validate experimentally proposed with 10 Gbaud 4-QAM 16-QAM signals at 30° 10° phase imbalance, respectively, simulated impairments. More specifically,...

The paper presents new A2iA bank check recognition systems designed to process handwritten and/or printed checks issued in France, UK or USA. All the have identical architecture and design principles. However, each of them contains a country-specific part is trained with data. Each system performs location, extraction, segmentation courtesy legal amounts document image, as well deciding whether accept reject check. rate 80-90%. In production mode, acceptance 60-75%, misread corresponding...

The seasonal pattern of concentrations nitrogen, starch and vegetative storage protein (VSP) in stolons Trifolium repens L. grown the field were studied. Two different genotypes, cv. Aran Rivendel, differing their morphology (stolon thickness branching rate) but with similar growth rates, used. Maximum found summer whereas hydrolysis took place throughout winter, suggesting that C is more important for winter survival than promotion early spring growth. On other hand, VSP nitrogen...

The authors propose an all-optical linearisation scheme for suppression of nonlinear distortion in semiconductor optical amplifiers. First experimental results show better than 10 dB reduction second order harmonic amplified sinusoidally amplitude modulated signal.

We numerically investigate the 2R-regeneration technique utilizing self-phase modulation and off-center filtering. Our numerical simulations take into account incoherent nature of noise through its spectral representation. This approach allows to evaluate a Q-factor improvement 2 dB for this regenerator. Furthermore, our study points out role both input output filter show that must be suitably chosen in order obtain best improvement. The also preserve format.

We experimentally investigate the operation of a cost-effective wavelength-division-multiplexed passive optical network (WDM-PON) based on wavelength-locked Fabry-Pérot laser diodes (FP-LDs). A single quantum-dash passively mode-locked (QD-MLL) is combined with an arrayed waveguide grating in WDM-PON architecture to provide low-noise, coherent multiwavelength seeding source injection-lock FP-LDs for both downstream and upstream. The results show that QD-MLL-injected FP-LD has same...

Bit-error-rate assessment of a multi-rate all-optical clock recovery (OCR) based on narrow linewidth mode-locked quantum-dot (QD) Fabry-Perot laser is presented in this letter. OCR has been achieved without external feedback. We use QD semiconductor designed for 40-GHz extraction. then present performance with 40-, 80-, and 160-Gb/s input data signal demonstrate that obtained thanks to subharmonic locking process. Results are through penalty measurement using an original characterization...

We realize a fiber Bragg grating InGaN-based laser diode emitting at 400 nm and demonstrate its high coherency. Thanks to the fabrication of narrowband in near-UV, we can reach single-mode single-frequency regimes for self-injection locked diode. The device exhibits 44 dB side-mode suppression ratio mW output power. Detailed frequency noise analysis reveals sub-MHz integrated linewidth 16 kHz intrinsic linewidth. Such narrow near-UV domain with compact low-cost design could find applications...

Abstract Different diets have been shown to leave characteristic patterns of microwear on the teeth various mammalian species. The quantification features facilitates comparison taxa, and allows discrimination wear associated with specific diets. current study reports a semiautomated image analysis procedure designed expedite by engaging an IBM PS/2 running OS/2 Presentation Manager compute record density, dimensions, orientations defined user employing mouse‐driven cursor. This technique is...

We studied the effects of stubble carbon / nitrogen (C N) reserves or residual leaf area (RLA) on contribution taproot C N to shoot regrowth Medicago sativa L. after cutting. The study assessed two cutting heights (6 and 15 cm), RLAs (0 100%), initial reserve levels (high low forage production, (N) distribution, dynamics within taproot. Alfalfa production was mainly affected by levels. However, organic (and a lesser extent RLA) were also particular importance during early regrowth. increase...

We experimentally investigate a new generation of multiple-quantum-well semiconductor saturable absorber for all-optical phase-shift-keying signal regeneration. The device under study exhibits reflectivity which decreases when the input power increases. This characteristic can be seen as limiting function could used phase-preserving amplitude noise reduction, hence preventing from nonlinear phase accumulation along transmission link. efficiency is demonstrated at 42.7 Gb/s; fiber launched...

A 170-Gb/s all-optical 2R regenerator made up of a fast saturable absorber and highly nonlinear-fiber-based power limiter is reported for the first time. Bit-error-rate assessment one four 42.5-Gb/s optical time-division-multiplexed tributaries shows receiver sensitivity improvement.

We report on the 1.5 μm laser emission from InAs quantum dots (QDs) grown a InP(311)B substrate. The control of optical wavelength is obtained by two-step modified growth procedure, called 'double cap' procedure. This enables us to obtain 1.55 InAs/InP(311)B QDs, with narrow height dispersion. Laser six-stacked QD layer sample has been demonstrated excitation at room temperature. Lasing an excited state, for low density 10 kW cm−2. shows that could emit telecommunication wavelength.