Potassium tetraborate tetrahydrate (KTBTH) single crystals were grown by slow evaporation solution growth method at room temperature. The grown crystal was characterized by single crystal X ray diffraction analysis. FT – IR and FT – Raman spectra were recorded to identify the functional groups. Optical transmission and absorption spectral studies were carried out to test the transmittance of th...

Fermi is a seeded FEL operating in high-gain harmonic generation mode. The FEL layout is constituted by a modulator and six radiators separated by a dispersive section. The modulator and the radiators can be tuned to the same resonant frequency to set up an asymmetric optical klystron configuration where self-amplified spontaneous emission can be generated and studied. This paper presents the e...

We observe optical third-harmonic generation in atomically thin films of MoS2 and deduce effective third-order nonlinear susceptibilities on the order of 10(-19) m(2)/V(2), which is comparable to that of commonly used semiconductors under resonant conditions. By measuring the susceptibility as a function of light wavelength, we find significant enhancements of the susceptibility by excitonic re...

Quasi-phase-matching is an important technique in nonlinear optics and is in widespread use. It not only makes efficient frequency conversion possible, but also enables diverse applications such as beam and pulse shaping, multi-harmonic generation, high harmonic generation, all-optical processing and the generation of entangled photons. However, since its introduction in the early 1960s at the ...

We present a study of the highly nonlinear optical excitation of noble gases in tapered hollow waveguides using few-femtosecond laser pulses. The local plasmonic field enhancement induces the generation of a nanometric plasma, resulting in incoherent extreme-ultraviolet fluorescence from optical transitions of neutral and ionized xenon, argon, and neon. Despite sufficient intensity in the waveg...

The nonlinear optical effect, such as two-photon (Denk et al., 1990) and three-photon (Maiti et al., 1997; Schrader et al., 1997; Wokosin et al., 1996) fluorescence significantly improved the depth resolution and reduced the background noise. The nonlinear optical techniques have been used to develop a new generation of optical microscopes with novel capabilities. These new capabilities include...

We report a theoretical study of third-harmonic generation (THG) microscopy by use of a Green’s function formulation. The third-harmonic signal under a tight-focusing condition is calculated for samples with various shapes and sizes. Our results show that THG signals can be efficiently generated at a sizable interface perpendicular or parallel to the optical axis or from a small object with a s...

High harmonic radiation, produced when intense laser pulses interact with matter, is composed of a train of attosecond pulses. Individual pulses in this train carry information on ultrafast dynamics that vary from one half-optical-cycle to the next. Here, we demonstrate an all-optical photonic streaking measurement that provides direct experimental access to each attosecond pulse by mapping emi...

We describe a new optical phase erasure characteristic of periodically poled lithium niobate (PPLN) by using cascaded second-harmonic generation and difference-frequency generation with the signal set at the quasi-phase-matching wavelength. A simple analytical expression is derived clearly explaining the operation principle. It is interesting that the optical phase erasure feature enables an al...