We have achieved rapid nonlinear vibrational imaging free of nonresonant background with heterodyne coherent anti-Stokes Raman scattering (CARS) interferometric microscopy. This technique completely separates the real and imaginary responses of nonlinear susceptibility chi(3) and yields a signal that is linear in the concentration of vibrational modes. We show that heterodyne CARS microscopy pe...

A novel method, which was called a slope method, has been proposed to measure fluid density by the micro-cantilever sensing chip. The theoretical formulas of the slope method were discussed and established when the micro-cantilever sensing chip was under flexural and torsional vibrations. The slope was calculated based on the fitted curve between the excitation and output voltages of sensing ch...

This work expands on previous studies to utilize hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) in high-temperature flames for background-free thermometry. The goal of the current work is to quantify the precision and accuracy of the temperature measurements over an expanded temperature range from 1250 – 2400 K, while also quantifying the influence of nonresona...

A strong super-Alfv\'{e}nic drift of energetic particles (or cosmic rays, CRs) in a magnetized plasma can amplify the magnetic field significantly through non-resonant streaming instability (NRSI). While traditional analysis is done for an ion current, here we use kinetic particle-in-cell simulations to study how NRSI behaves when it driven by electrons or mixture and positrons. In particular, ...

A central premise of nearly all theories of dissociative electron attachment is that this process is resonance driven. Neglect of nonresonant scattering, although appropriate for electron-molecule systems with narrow (long-lived) resonances, is problematic for the e-H2 system, which has one of the broadest known resonances. Using the nonadiabatic phase-matrix method we have found that at energi...

We demonstrate a scheme for efficient coherent anti-Stokes Raman scattering (CARS) microscopy free of nonresonant background. Our method is based on a compact Er:fiber laser source. Impulsive excitation of molecular resonances is achieved by an 11 fs pulse at 1210 nm. Broadband excitation gives access to molecular resonances from 0 cm(-1) up to 4000 cm(-1). Time-delayed narrowband probing at 77...

The plasma response to resonant magnetic perturbation RMP and nonresonant perturbation fields is computed within a linear, full toroidal, single-fluid resistive magnetohydrodynamic framework. The response of resonant harmonics depends sensitively on the plasma resistivity and on the toroidal rotation. The response of nonresonant harmonics is not sensitive to most of the plasma parameters, excep...