Measurement of pressure dependent nonlinear refractive index of inert gases

Abstract

The propagation of high intensity laser beams is excessively affected by optical nonlinear effects, thereby the knowledge of the nonlinear refractive indices of the beam guiding media is indispensable in the design of laser systems and experiments. Apart from undesired self-focusing, several areas of modern laser spectroscopy can utilize optical nonlinearity, from LiDAR measurements to filamentation. In this paper we report on a direct measurement of pressure dependent nonlinear refractive index of Ar, N2, Ne, Xe, and air between 0.05 mbar and 1 bar, based on the powerful technique called spectrally and spatially resolved interferometry. In this way the total value of nonlinear refractive index is measured, that is the sum of all elementary phenomena contributing to the intensity dependent refractivity of the gases.

Carrier-envelope phase-dependent high harmonic generation in the water window using few-cycle infrared pulses

“…This experiment was carried out in the same run with the equivalent parameters as those used in the previous measurement. The peak power of the infrared pulses was 38 GW, which is approximately two times more than the critical power of 21 GW for self-focusing when the pressure of neon is set at 1.0 atm (Börzsönyi et al 25). Figure 4a shows the CEP dependence of soft X-ray spectra measured at a backing pressure of 1.0 atm.…”

Ultraviolet Light Generation in Gas-Filled Kagome Photonic Crystal Fiber

“…This is illustrated in Figure 2, which presents the spatial distribution of the optical field for a kagome HC-PCF with core diameter d = 40.0 μm and thickness t = 0.1 μm. The core filling gas has a Kerr coefficient, n kerr , given by the expression [15] …”

Notched Long-Period Fiber Grating with an Amine-Modified Surface Nanostructure for Carbon Dioxide Gas Sensing

“…Various techniques for detecting gas have been developed for applications such as environment monitoring [9], medical diagnosis [10], chemical and mining safety [11], and modern gas laser designs [12]. Among these techniques are several effective optical methods for detecting the gas, including interferometry [13], absorption spectroscopy [14], surface plasmon resonance [15], fluorescence spectroscopy [16], and grating-based refractive index transmission [17].…”