By means of the ultrafast optical Kerr effect method coupled to optical heterodyne detection (OHD-OKE), we characterize the third-order nonlinear response of graphene and compare it to experimental values obtained by the Z-scan method on the same samples. From these measurements, we estimate a negative nonlinear refractive index for monolayer graphene, n2=-1.1×10-13  m<sup...

A high-capacity ion trap coupled to a time-of-flight (TOF) mass spectrometer has been developed to carry out comprehensive linked scan analysis of all stored ions in the ion trap. The approach involves a novel tapered geometry high-capacity ion trap that can store more than 10(6) ions (range 800-4000 m/z) without degrading its performance. Ions are stored and scanned out from the high-capacity ...

We report on the investigation of the nonlinear optical properties of castor oil using the Z-scan technique. Nonlinear refraction and absorption measurements were performed for two different laser wavelengths, 514 and 810 nm, in the CW regime, and for 810 nm in femtosecond regime. The CW results showed that castor oil has a large negative nonlinear refractive index n2 = -3.2 x 10 cm/W for the l...

In the present work, The third order optical nonlinearity and optical limiting properties of Magnesium phthalocyanine (MgPc) thin film have been investigated. Third order optical nonlinearity of MgPc thin film has been studied by z–scan method using a cw He-Ne laser at ~633nm wavelength as an exciting source. The normalized transmission for both open and closed aperture z scan are measured and ...

The diffusion of fluorescently labeled lipids in supported bilayers is studied using two different methods: Z-scan fluorescence correlation spectroscopy (z-scan FCS) and two-focus fluorescence correlation spectroscopy (2f-FCS). It is found that the data can be fitted consistently only when taking into account partial sticking of the labeled lipids to the supporting glass surface. A kinetic reac...

Physical properties of oxidized phospholipid (OxPL) membranes consisting of binary mixtures of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 10 mol % of one of two OxPLs, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine (PGPC) or 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), were investigated experimentally and computationally. Fluorescence solvent relaxat...

There is a high demand for 3D multiphoton imaging in neuroscience and other fields but scanning in axial direction presents technical challenges. We developed a focusing technique based on a remote movable mirror that is conjugate to the specimen plane and translated by a voice coil motor. We constructed cost-effective z-scanning modules from off-the-shelf components that can be mounted onto st...

We have investigated the nonlinear optical properties, optical limiting thresholds, and figures of merits for five different phthalocyanine thin films, achieved through doping in PMMA polymer, using the Z-scan technique at 800 nm with 2 ps laser pulse excitation. From the open-aperture Z-scan data we derived that these molecules exhibit strong two photon absorption (2PA) with the nonlinear abso...

BACKGROUND Patients with spina bifida frequently sustain lower extremity fractures which may be difficult to diagnose because they feel little or no pain, although the relative contributions of low bone density to pain insensitivity are unclear. Routine dual-energy xray absorptiometry (DXA) scanning is unreliable because these patients lack bony elements in the spine, and many have joint contra...

Scan detection and suppression methods are an important means for preventing the disclosure of network information to attackers. However, despite the importance of limiting the information obtained by the attacker, and the wide availability of such scan detection methods, there has been very little research on evasive scan techniques, which can potentially be used by attackers to avoid detectio...