Nonlinear absorption and optical damage threshold of carbon-based nanostructured material embedded in a protein

Physical processes in laser–matter interaction used to be determined by generation of fast electrons resulting from efficient conversion of the absorbed laser radiation. Composite materials offer the possibility to control the absorption by choice of the host material and dopants. Reported here strong absorption of ultrashort laser pulse in a composite carbon-based nanomaterial including single-walled carbon nanotubes (SWCNTs) or multilayer graphene was measured in the intensity range between 1012 and 1016 W cm-2. A protein (lysozyme) was used as the host. The maximum absorption of femtosecond laser pulse has reached 92–96 %. The optical damage thresholds of the coatings were registered at an intensity of (1.1 ± 0.5) 9 1013 W cm-2 for the embedded SWCNTs and at (3.4 ± 0.3) 9 1013 W cm-2 for the embedded graphene. Encapsulated variant of the dispersed nanomaterial was investigated as well. It was found that supernatant protein in the coating material tends to dominate the absorption process, independently of the embedded nanomaterial. The opposite was observed for the encapsulated material.1351sciescopu

Multilayer reflector for polarization analysis of XUV radiation

Schulze D, Sommerer G, Drescher M, et al. Multilayer reflector for polarization analysis of XUV radiation. In: X-RAY LASERS 1996. IOP PUBLISHING LTD; 1996: 353-357.A multilayer mirror arrangement is used to measure the polarisation characteristics of high harmonics (59 th and 61 st order, lambda approximate to 17 nm) with a high degree of accuracy. The reflectivity of the Mo/Si multilayer mirror is about 60 %, and its polarization analyzing power is close to unity at a wavelength of 17 nm. We observed for the harmonics in the cutoff region that there is no rotation with respect to the fundamental light. For linear and slightly elliptical laser polarization the harmonics still remain linear polarized

Polarization of the 61st harmonic from 1053-nm laser radiation in neon

Schulze D, Dorr M, Sommerer G, et al. Polarization of the 61st harmonic from 1053-nm laser radiation in neon. PHYSICAL REVIEW A. 1998;57(4):3003-3007.We report the polarization measurement of a very high order (59th and 61st order, similar to 17 nm) harmonic. A Mo-Si multilayer mirror is used as a polarizer with reflectivity of 60% and polarization analyzing power close 'to unity around a wavelength of 17 nm. We observe that for these high harmonics in Ne there is no rotation of the polarization ellipse with respect to the fundamental laser polarization, even though the harmonics are in the plateau. For linear and slightly elliptical laser polarization the harmonics still remain linearly polarized. These findings are supported by a full theoretical simulation, which includes spatiotemporal integration and phase matching of the emitted harmonic radiation

Transient electric fields in laser plasmas observed by proton streak deflectometry

A novel proton imaging technique was applied which allows a continuous temporal record of electric fields within a time window of several nanoseconds. This "proton streak deflectometry" was used to investigate transient electric fields of intense (~ 10^17 W/cm^2) laser irradiated foils. We found out that these fields with an absolute peak of up to 10^8 V/m extend over millimeter lateral extension and decay at nanosecond duration. Hence, they last much longer than the (~ ps) laser excitation, and extend much beyond the laser irradiation focus