4. Conclusions

This type of Holography takes into consideration the coherent process at low frequency ω<sup>p</sup> � ω<sup>s</sup> (or ω<sup>a</sup> � ω<sup>p</sup> which may coincide with the vibration frequencies of biomolecules. The popularity of coherent Raman scattering techniques in optical microscopy increases and it may be developed using another type of coherence described in the section. The holography developed on the bases of coherence proprieties between the two- (or three) conjugate modes of the scattering field opens this possibility not only for the description of the spectral diapason and time dependence of scattered field intensity, but the topological aspects of the molecular structures manifested in holographic representations of the vibrational modes of molecules. The coherence proposed in the Section 2 B needs the low intensity of each mode component in comparison with traditional Raman diagnostic proposed in Refs. [14, 15]. Using the coherent proprieties, described at the point B of the last section, we can estimate a lot of peculiarities connected with geometrical structures of biomolecules for lower intensities of each mode component of Raman process described by Refs. [14, 15]. In this case the transmission can be detected by the scheme proposed in Figure 9 on the plan ð Þ x; y , where the interpretation of Holo-

gram imaging can be expressed in classical terms.

Gr2GO<sup>2</sup>

p cos arg Π<sup>þ</sup>

The entanglement between each mode of the field can be detected by twophoton detector schemes, placed in the plan of hologram represented in Figure 9. This procedure may be in tangency with proposed experimental detections of

In comparison with the spontaneous parametric down-conversion the superradiance [21] or cooperative scattering processes [12, 13] represented generators of non-classical light source—the two-photon quantum entangled state with the coherent aspects between the two conjugate modes. Two-modes from such processes may become incoherent, but the coherence can be revived in the two-photon excitations of the detector which represents the photon pairs from adjacent modes. The two-photon detection scheme an interference connected to it is shown in Figure 6. The similar effect appears between stokes, pump, and anti-Stokes photon

in induced scattering. In the pioneer theoretical work of two-photon optics, Belinskii and Klyshko [7] predicted three spooky schemes: two-photon diffraction, two-photon holography, and two-photon transformation of two-dimensional images. The first and last schemes have been demonstrated in the experiments,

Two-photon coherent light and principle of hologram registration taking into consideration the phase and

amplitude of the three modes of Raman scattered field Stokes, pump and anti-Stokes modes.

<sup>O</sup>ð Þ <sup>0</sup>; <sup>t</sup> � � � arg <sup>Π</sup><sup>þ</sup>

<sup>r</sup> ð Þ <sup>r</sup>; <sup>t</sup> <sup>þ</sup> <sup>τ</sup> � � � � (12)

Ts <sup>¼</sup> GO<sup>2</sup> <sup>þ</sup> Gr<sup>2</sup> <sup>þ</sup> <sup>2</sup> ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi

Quantum Cryptography in Advanced Networks

vibration modes of biomolecules [8, 9].

Figure 9.

56

The encrypted information, using the coherence of multi-mode bimodal field in quantum holography, opens the new perspective, in which the coherence proprieties between bi-photons are used together with non-local states of entangled photon pairs. The possibilities to use this coherence in the quantum communication and holographic registration of objects is described by the expressions (9) and (10) and is proposed for future developments. The main distinguish between the traditional holograms and such a hologram registration becomes attractive from physical points of view because it must take into consideration the common phase of two light modes described by the expressions (9)-(12). It also discusses the cooperative behavior of three cavity modes which corresponds to pump, Stokes and anti-Stokes photons stimulated by the atomic inversion. A new type of cooperative generation described by the correlations of the expressions (1) and (4) may be used in quantum nucleonics [36] as an ignition mechanism of coherence generation gamma photons by long-lived nuclear isomers in the single and two-quantum interaction with other species of excited radiators.

This method of recording of information affords the new perspectives in quantum cryptography and quantum information and has the tendency to improve the conception about quantum holograms observed in in literature [5, 7–9]. All these methods open new possibilities in the coding and decoding of data.
