34
1 Resonance Methods for Increasing Sensitivity of Interferometry …
1.4.1 To the Question of Creation of Radiation Coherence
Source with the Wavelength L a (121.6 Nm)
for the Study of Hydrogen Atoms Concentration
in Plasma by the Method of Resonance Fluorescence
One of the possible methods of receiving coherence radiation in vacuum spectral
region is the generation of the third harmonic in the medium with high third-order
nonlinearity [81, 82]. High efficiency of transformation can be achieved under the
condition of phase matching.
Near resonance lines, it is possible due to anomalous dispersion. Similar experiments were carried out in xenon [83] and its mixture with argon [84]. In our experiments as nonlinear medium, krypton has been chosen. Its resonance line is λ =
123.6 nm, and it is at a distance of 2 nm from resonance line of hydrogen atom L a .
During the experiments, the optical scheme of the setup illustrated in Fig. 1.23a
was used. As an exciting source of the third harmonic generation in krypton optical
quantum generator, “Raduga-6” on organic dye solution was used (Fig. 1.22). It
enables to get high-power generation with gradually tuned spectrum in the range of
260–1200 nm [78]. OQG “Raduga-6” consists of the master laser on solutions (1), two
amplifiers (2, 3) and the output crystal KDR (4), which enables to broaden spectral
working range in ultraviolet region. Excitation of OQG and two dye amplifiers is
carried out using the monopulse ruby laser (5) with three amplifiers (6, 7, 8). With
the help of “Raduga-6”, it becomes possible to get radiation on the wavelength of
369.6 nm with energy of 0.1 J and with the duration of ≈10
−8 s. Radiation spectral
width was ≈10
−2 nm.
The cell (3) with the length of 11 cm was filled with spectroscopically pure
krypton where impurity content was no more than 0.1%. Laser radiation in the cell
was focused with the help of the lens (2) at a distance of 3 cm from the input window.
The third harmonic isolation from the exciting radiation (λ = 369.6 nm) was carried
Fig. 1.22 Scheme of optical quantum generator “Raduga 6” on organic dye solution. Reprinted
from [54] with permission
1 Resonance Methods for Increasing Sensitivity of Interferometry …
1.4.1 To the Question of Creation of Radiation Coherence
Source with the Wavelength L a (121.6 Nm)
for the Study of Hydrogen Atoms Concentration
in Plasma by the Method of Resonance Fluorescence
One of the possible methods of receiving coherence radiation in vacuum spectral
region is the generation of the third harmonic in the medium with high third-order
nonlinearity [81, 82]. High efficiency of transformation can be achieved under the
condition of phase matching.
Near resonance lines, it is possible due to anomalous dispersion. Similar experiments were carried out in xenon [83] and its mixture with argon [84]. In our experiments as nonlinear medium, krypton has been chosen. Its resonance line is λ =
123.6 nm, and it is at a distance of 2 nm from resonance line of hydrogen atom L a .
During the experiments, the optical scheme of the setup illustrated in Fig. 1.23a
was used. As an exciting source of the third harmonic generation in krypton optical
quantum generator, “Raduga-6” on organic dye solution was used (Fig. 1.22). It
enables to get high-power generation with gradually tuned spectrum in the range of
260–1200 nm [78]. OQG “Raduga-6” consists of the master laser on solutions (1), two
amplifiers (2, 3) and the output crystal KDR (4), which enables to broaden spectral
working range in ultraviolet region. Excitation of OQG and two dye amplifiers is
carried out using the monopulse ruby laser (5) with three amplifiers (6, 7, 8). With
the help of “Raduga-6”, it becomes possible to get radiation on the wavelength of
369.6 nm with energy of 0.1 J and with the duration of ≈10
−8 s. Radiation spectral
width was ≈10
−2 nm.
The cell (3) with the length of 11 cm was filled with spectroscopically pure
krypton where impurity content was no more than 0.1%. Laser radiation in the cell
was focused with the help of the lens (2) at a distance of 3 cm from the input window.
The third harmonic isolation from the exciting radiation (λ = 369.6 nm) was carried
Fig. 1.22 Scheme of optical quantum generator “Raduga 6” on organic dye solution. Reprinted
from [54] with permission