Femtosecond stimulated Raman scattering in pressurized gases in the ultraviolet and visible spectral ranges

High-efficiency bispectral laser for EUV

“…This effect causes the complicated behavior of the amplification increment for the short laser pulses in the non-stationary SRS mode. The expression for the Stokes signal gain of the non-stationary SRS (in the approximation) for a given pump can be written as follows [11]: So in the work [12] one observed the line particularities in the H2-Ar gas mixture and they were interpreted in terms of collision theory. The coefficient 4.6 • 10 -3 sm -1 /amagat of SpRS line broadening for the gas mixture with ratio hydrogen/argon of 1/50 at the temperature of 295K was obtained experimentally [12,13].…”

“…However it leads to a decrease of the non-stationary process influence. When the hydrogen density come up to 25 amagat (pressure about 25 atm) T2  200 ps and the SRS mode becomes essentially non-stationary already when the pump pulse duration is less than 2 ns [11]. Thus, the addition of buffer gas will partially reduce the effect of the non-stationary processes and this fact can be used to create the SRS radiation generator with a pulse duration ~ 100 ps or less.…”

Growth and spectral properties of pure and Nd3+-doped Ba3(VO4)2 crystals

“…In recent years, a great deal of attention has been focused on developing stimulated Raman scattering (SRS) crystals due to extending the spectral region of solid-state laser sources including yellow, orange, and eye-safe wavelengths [1][2][3]. In the research of highly efficient Raman crystals, such as Ba(NO 3 ) 2 and BaWO 4 crystals, it was discovered that Ba 2+ with large radius and heavy mass decreased the interaction between internal and external Raman modes of Raman crystal, which decreased the lattice vibration mode frequency of Raman crystal and simultaneously increased the peak SRS cross-section of Raman crystal [4,5].…”

Comparison of SRS thresholds under pumping by Gaussian and Bessel beams

“…The diffraction also plays an important part in the formation of a Stokes flux under SRS in strongly focused fields. Under such conditions the plane-wave approximation is inapplicable in the SRS theory and analysis of experimental data should be carried out on the basis of more general approaches, many of which were proposed in [11,12,[15][16][17][18][19][20]. However, the problem of describing the SRS with allowance for the transverse structure of the field and the action on it of the processes of SRS amplification and diffraction cannot thus far be considered to be solved.…”

“…In writing relations (15) and (16), it was assumed that exp (B BB (z)) >> 1 and the coefficient before the exponent weakly depends on γ and z compared to the exponent. If necessary, the expressions for the derivatives of M BB (z, q _ ) and, consequently, the values of B 1 (z) and B 2 (z) can easily be obtained from formula (14).…”