Parabolic pulse generation with active or passive dispersion decreasing optical fibers

We experimentally demonstrate the possibility to generate parabolic pulses via a single dispersion decreasing optical fiber with normal dispersion. We numerically and experimentally investigate the influence of the dispersion profile, and we show that a hybrid configuration combining dispersion decrease and gain has several benefits on the parabolic generated pulses

Nonlinear femtosecond pulse propagation in an all-solid photonic bandgap fiber

Nonlinear femtosecond pulse propagation in an all-solid photonic bandgap fiber is experimentally and numerically investigated. Guiding light in such fiber occurs via two mechanisms: photonic bandgap in the central silica core or total internal reflection in the germanium doped inclusions. By properly combining spectral filtering, dispersion tailoring and pump coupling into the fiber modes, we experimentally demonstrate efficient supercontinuum generation with controllable spectral bandwidth

Wavelength conversion and temporal compression of a pulse train using a dispersion oscillating fibre

International audienceWe demonstrate the generation of a picosecond pulse train taking advantage of the cross gain occurring in a dispersion oscillating fibre. The resulting frequency-converted signal is detuned by more than 20 nm from the pump and can be temporally compressed by a factor 2 compared to the input sinusoidal pump wave

From nanotechnology to nanomedicine: applications to cancer research

Scientific advances have significantly improved the practice of medicine by providing objective and quantitative means for exploring the human body and disease states. These innovative technologies have already profoundly improved disease detection, imaging, treatment and patient follow-up. Today's analytical limits are at the nanoscale level (one-billionth of a meter) enabling a detailed exploration at the level of DNA, RNA, proteins and metabolites which are in fact nano-objects. This translational review aims at integrating some recent advances from micro- and nano-technologies with high potential for improving daily oncology practice

Experimental demonstration of spectral sideband splitting in strongly dispersion oscillating fibers

By using a highly nonlinear, dispersion oscillating optical fiber operating in the telecom C band, we experimentally demonstrate the splitting experienced by quasi-phase matched gain sidebands in the strongly dispersion managed regime of a dispersion oscillating fiber as the power of a continuous-wave pump laser is increased over a certain threshold value. Very good agreement is found between the theoretical predictions and our experimental measurements

Contact Force Dependence on Relative Humidity: Investigations Using Atomic Force Microscopy

This paper deals with the ability of scanning force microscopy to determine contact forces of various materials. Indeed, with high spring constants at low relative humidity, the nature of the material can be determined by measurement of the contact force as the tip approaches. Cantilevers with a high spring constant are used to achieve solid-solid contact for the tip-sample system. The capillary force estimation provides information on the development of the height of the water meniscus formed between the tip and different surfaces depending on the relative humidity. Finally, we focus our attention on measurements of moduli of elasticity which vary with the physicochemical processes (precipitation, dissolution, water intercalation, dehydration) instigated by the variation in humidity. All experiments were conducted on various surfaces: more extensively on gypsum, but also on calcite, mica, graphite, brucite, aluminum, silver and glass

Enhanced nonlinear spectral compression in fiber by external sinusoidal phase modulation

We propose a new, simple approach to enhance the spectral compression process arising from nonlinear pulse propagation in an optical fiber. We numerically show that an additional sinusoidal temporal phase modulation of the pulse enables efficient reduction of the intensity level of the side lobes in the spectrum that are produced by the mismatch between the initial linear negative chirp of the pulse and the self-phase modulation-induced nonlinear positive chirp. Remarkable increase of both the extent of spectrum narrowing and the quality of the compressed spectrum is afforded by the proposed approach across a wide range of experimentally accessible parameters

The Bolivian Decentralization Process and the Role of Municipal Associations

This discussion paper looks at the Bolivian decentralization model. The objective of Bolivian decentralization is to consolidate the process of popular participation, and to promote regional economic development by means of a more equitable distribution of national income and improved administration of public resources. The legal framework of Bolivian decentralization is established by two principled laws; firstly, the LPP, defines decentralization on the municipal level and represents a new dimension of governmental reform, creating an important link between the state and civil society. Second, the Law of Administrative decentralization (LAD-adm) organizes the structure of the executive power in each Department so as to underpin administrative decentralization. Overall the decentralization process in Bolivia can be seen as an important step towards restructuring the old centralized state into a more democratic one. However, as the social uprising and protests which took place in October 2003 show, the decentralization laws alone didn?t solve the economic and social problems in Bolivia

On-chip generation of high-dimensional entangled quantum states and their coherent control

Optical quantum states based on entangled photons are essential for solving questions in fundamental physics and are at the heart of quantum information science1. Specifically, the realization of high-dimensional states (D-level quantum systems, that is, qudits, with D > 2) and their control are necessary for fundamental investigations of quantum mechanics2, for increasing the sensitivity of quantum imaging schemes3, for improving the robustness and key rate of quantum communication protocols4, for enabling a richer variety of quantum simulations5, and for achieving more efficient and error-tolerant quantum computation6. Integrated photonics has recently become a leading platform for the compact, cost-efficient, and stable generation and processing of non-classical optical states7. However, so far, integrated entangled quantum sources have been limited to qubits (D = 2)8, 9, 10, 11. Here we demonstrate on-chip generation of entangled qudit states, where the photons are created in a coherent superposition of multiple high-purity frequency modes. In particular, we confirm the realization of a quantum system with at least one hundred dimensions, formed by two entangled qudits with D = 10. Furthermore, using state-of-the-art, yet off-the-shelf telecommunications components, we introduce a coherent manipulation platform with which to control frequency-entangled states, capable of performing deterministic high-dimensional gate operations. We validate this platform by measuring Bell inequality violations and performing quantum state tomography. Our work enables the generation and processing of high-dimensional quantum states in a single spatial mode