Doppler broadening

About: Doppler broadening is a research topic. Over the lifetime, 5509 publications have been published within this topic receiving 92552 citations.

Five‐chord high‐resolution x‐ray spectrometer for Alcator C‐Mod

Abstract: A five‐spectrometer array has been designed to provide high‐wavelength resolution x‐ray spectra from the Alcator C‐Mod plasma Each independently scannable von Hamos type spectrometer consists of a variable entrance slit, quartz crystal, and position sensitive proportional counter, and has 3 cm spatial resolution with a resolving power of 4000 The wavelength range of each spectrometer is from 28 to 40 A, which covers the complete Rydberg series of helium‐ and hydrogen‐like argon Wavelengths are remotely selectable, with 120 mA covered at any one setting The array will provide single shot ion temperature profiles by measuring the Doppler broadening of the resonance lines of argon Five proportional counters have been fabricated and all five spectrometers have been constructed Calibration spectra using cadmium and scandium anode sources have been obtained, and measured performance characteristics are presented

Photoionization of silicate glasses exposed to IR femtosecond pulses

Abstract: Photoionization of alkali-silicate, boro-silicate, lead-silicate and photosensitive multi-component silicate glasses has been studied under exposure to infrared femtosecond laser pulses at irradiance below the thresholds of laser-induced damage and catastrophic self-focusing. It is proved that the supercontinuum that is generated in all glasses studied as a result of the femtosecond laser pulses spectral broadening extends up to the short-wavelength part of the ultraviolet region of spectrum even if the glass is opaque in this region. It is shown that photoionization results from absorption of the short-wavelength component of this supercontinuum generated by infrared radiation. This ionization leads to the color center formation and luminescence in the bulk of glasses studied. Photoionization of photosensitive multi-component glasses leads to the creation of latent image and to the refractive index changing in exposed area after thermodevelopment. Fused silica exhibits the same spectral broadening too but color center formation in the visible was not recorded at irradiance up to the laser damage threshold.

Soliton explosion driven multi-octave supercontinuum generation by geometry-enforced dispersion design in antiresonant hollow-core fibers

Abstract: Ultrafast supercontinuum generation in gas-filled waveguides is one enabling technology for many intriguing application ranging from attosecond metrology towards biophotonics, with the amount of spectral broadening crucially depending on the pulse dispersion of the propagating mode. Here we show that the structural resonances in gas-filled anti-resonant hollow core optical fiber provide an additional degree of freedom in dispersion engineering, allowing for the generation of more than three octaves of broadband light ranging deep UV wavelength towards the near infrared.Our observation relies on the introduction of a geometric-induced resonance in the spectral vicinity of the pump laser outperforming the gas dispersion, thus yielding a dispersion being independent of core size, which is highly relevant for scaling input powers.Using a Krypton filled fiber we observe spectral broadening from 200 nm towards 1.7 \mu m at an output energy of about 23 \mu J within a single mode across the entire spectral bandwidth. Simulations show that the efficient frequency generation results from a new physical effect the soliton explosion originating from the strongly non-adiabatic mode dispersion profile.This effect alongside with the dispersion tuning capability of the fiber will enable compact ultrabroadband high energy sources spanning from the UV to the mid-infrared spectral range.

Dynamic stark effect of an optical line observed by cross-saturated absorption

Abstract: Cross-saturated absorption at the neon line 2s 2–2p 4 caused by the saturating line 3s 2–2p 4 has been applied to the observation of the dynamic Stark effect by 1) power broadening, due to triple-quantum and higher multiple-quantum transitions, of the light shift contribution to the susceptibility, and 2) a direct splitting in the electronic Raman-Stokes contribution which occurs because of the partial compensation of the Doppler broadening.