Non-thermal response of YBCO thin films to picosecond THz pulses

The photoresponse of YBa2Cu3O7-d thin film microbridges with thicknesses between 15 and 50 nm was studied in the optical and terahertz frequency range. The voltage transients in response to short radiation pulses were recorded in real time with a resolution of a few tens of picoseconds. The bridges were excited by either femtosecond pulses at a wavelength of 0.8 \mu m or broadband (0.1 - 1.5 THz) picosecond pulses of coherent synchrotron radiation. The transients in response to optical radiation are qualitatively well explained in the framework of the two-temperature model with a fast component in the picosecond range and a bolometric nanosecond component whose decay time depends on the film thickness. The transients in the THz regime showed no bolometric component and had amplitudes up to three orders of magnitude larger than the two-temperature model predicts. Additionally THz-field dependent transients in the absence of DC bias were observed. We attribute the response in the THz regime to a rearrangement of vortices caused by high-frequency currents

Efficiency of initial presbyopia functional correction in visually intensive work persons

Aim: To study the efficacy of functional (physiotherapeutic) stimulation of an eye in visually intensive work patients with the initial symptoms of presbyopia.Methods: 104 visually intensive work patients before and after complex physiotherapy (low-energy laser radiation, magnitotherapy, stimulation of accommodation) were examined.Results: Physiotherapy improved near vision (by 0.16 RU on average) and subjective psychophysiological status (by 11.8 %) and reduced eye strain (by 2.1 times). Additionally, objective accommodography indices improved, brightness sensitivity thresholds decreased by 16.5 %, and psychological status improved by 18.2 %. These positive effects of physiotherapeutic stimulation enabled to delay eyeglasses prescription for 6 months in 76 % of patients and for 9 months in 42 % of patients.Conclusion: Functional (physiotherapeutic) stimulation provides effective correction of initial presbyopia in visually intensive work persons