A high-power linearly polarized laser propagating through a plasma produces oscillatory electron velocity at the second harmonic due to the v x B force. This velocity couples a Langmuir wave (ui,k) and an electromagnetic wave (wi,fci), where w\ = LO 2u0 , fei = k — 2kQ and u>0, k0 are frequency and wavenumber of the laser pump, causing second harmonic Raman scattering. The growth rate is maximu...

Planar metasurface based quarter-wave plates offer various advantages over conventional waveplates in terms of compactness, flexibility and simple fabrication; however they offer very narrow bandwidth of operation. Here, we demonstrate a planar terahertz (THz) metasurface capable of linear to circular polarization conversion and vice versa in a wide frequency range. The proposed metasurface is ...

The effect of the different polishing conditions for niobium has been investigated as basic data superconducting quarter-wave resonators (QWRs) in booster linac Tokai-tandem accelerator. Surface roughness and desorbed hydrogen amount samples with such method (electropolishing: EP or chemical polishing: CP), thickness, electrode location, have measured. For measurement, thermal desorption spectr...

A theoretical analysis of a fiber optical photonic band gap based tunable wavelength filter is presented. The design presented here is based on the quarter wave reflector with a liquid crystal defect layer in the middle of the structure. The filter generated by the structure is shifted in wavelength as the voltage applied to the structure is modified. Some critical parameters are analyzed: the ...

Examining spectral regions outside of the band where an antireflection coating is specified can aid in finding optimal design solutions. The reflectance versus wavenumber plots at low frequencies indicate the overall thickness of the design. These plots also point to whether the design will provide the minimum possible average reflectance in the specified band. It has been discovered that these...