Y. Ping

Transmission of laser radiation through microcapillary plasmas

Propagation of laser radiation through a plasma, created in microcapillaries, has been investigated under various experimental conditions, which are closely related to x-ray laser development. It has been shown that the absorption of laser radiation in a microcapillary plasma depends on the microcapillary diameter as well as on the laser parameters and provides a good lead for the process of optimization of the soft-x-ray gain generation. Real-time nonintrusive plasma probing with a low-intensity He–Ne laser beam has also been performed.

Interferometric measurements of plasma density in microcapillaries and laser sparks

The spatial and temporal evolution of electron density in laser- and discharge-created plasmas in microcapillaries and laser sparks in gases, has been measured by interferometry. The results are compared and the features of these three types of plasmas are summarized from the point of view of x-ray lasers and Raman amplification of ultrashort pulses.

Experimental and Theoretical Simulations for Conditions for Lasing at 13.5 nm in LiIII

We present results related to the search for optimum conditions for lasing to ground state of H‐like LiIII ions at 13.5 nm. These conditions are being considered from the point of view of the development of a prototype of a very compact 13.5 nm laser for metrology of soft x‐ray (EUV) lithography. Theoretical simulations are discussed in relation to experimental data. Experiments on channeling of ultrashort high intensity pumping laser beam in microcapillary plasma are presented for conditions appropriate for lasing at 13.5 nm. We are also discussing Raman amplification of ultrashort pulses in microcapillary plasma as a possibility for future use in X‐ray lasers.

Search For Optimum Conditions For Gain To Ground State In Liiii

The optimum conditions for gain generation for the transition to the ground state at 13.5 nm in Liiii ions were investigated in discharge created pre‐plasma. The spatial and temporal evolution of plasma density was measured and a hollow density profile was observed. Waveguiding of high power laser pulses has been demonstrated in discharge created plasma channels, which can be helpful in increasing the interaction length, thus improving the gain‐length product.

Raman Amplification of Laser Pulses in Microcapillary Plasmas

Raman amplification of ultrashort pulses is demonstrated in microcapillary plasmas. Experiments in very short microcapillaries (0.2 – 0.5 mm) with a broadband seed pulse show that the amplification factor is in agreement with the linear growth rate.