## 3 Results and Discussion
### The Radiation Diffraction on the Structure
The qualitative proximity of the field distribution in Figure 3a,c is explained by the fact that a node of a standing wave is located in the center of the end face of the blade. Field distribution in Figure 3b differs significantly from the previous ones owing to the fact that the antinode of the standing wave is located approximately in the center of the end face of the blade. We emphasize that near the nanosized edge of the blade, there is a significant deformation of the field distribution. As a result of this, in particular, the period of following nodes and antinodes decreases. Formula (2) allows to quantify the specific power level of the absorbed photons and identify the patterns of their dependence on the absorption depth based on the analysis of results of spectral distribution estimation of the function presented in Figure 4. The calculation is carried out in the vicinity of point 2 (the designation is entered in Figure 3), which is located at the interface of the emitter tip rounding with its end surface. The curves in Figure 4 correspond to the specific absorption rate determined at different depths from the surface, starting from zero and ending at the depth of 20 nm. Additionally, we take into account that the data relating the specific absorbed power level are important in terms of estimating potential efficiency of the photosensor, as it is proportional to the concentration of hot electrons. Then, the top four curves in Figure 4 give a quantitative characteristic of the absorbed photon power, which is spent on excitation of the electrons, which can transport to the surface of the emitter (the depth is less than the free path of the hot electron in molybdenum \(L_{\tau}=10\) nm). An unexpected result referred not to the maxima or minima of the spectral absorption function, but to their significant difference in the magnitude (by 5-8 times depending on the wavelength of the radiation). The concentration of the hot electrons changes accordingly. It is also seen that the attenuation degree of the optical signal as the function of depth has spectral dependence. The observation point over the surface of the emitter tip was chosen arbitrarily during the computational experiment. However, an additional investigation demonstrated the existence of similar patterns in the other points across the emitter parameter. Figure 3: Spatial distributions of the normalized squared modulus of the electric field vector \(|\vec{E}|^{2}/|\vec{E}_{0}|^{2}\) near the emitter in the vacuum (right tone scale) and inside the molybdenum emitter (left tone scale). The wavelength of the irradiating light is (**a**) 430 nm, (**b**) 500 nm, and (**c**) 550 nm. In particular, this evidence is provided by the results of numerical simulation of the function \(|E|^{2}/|E_{0}|^{2}\) built along the perimeter of the blade generator inside molybdenum (Figure 5a), and within the vacuum (Figure 5b) when exposed to light with different wavelengths. Here, Figure 5c,d show distribution of the modulus of electrostatic field intensity when applied to the gate of the potential \(\mathrm{U}_{g}=1\,\mathrm{V}\) (along the perimeter of the blade generator outside the emitter and a two-dimensional distribution near the tip of the emitter, respectively). The electrostatic field is also characterized by a certain degree of localization. However, the actual localization zone does not change the position compared with the spectral dependence of the position of optical field intensity extrema. Figure 4: Spectral dependences of the normalized specific absorption power of optical radiation over the surface and different depths (0, 2, 6, 10, and 20 nm) inside the molybdenum emitter, estimated in the vicinity of point 2 indicated in Figure 3.  
Figure 5: _Cont._  
It is obvious that efficiency of the analyzed structure of the photosensor will improve if an additional adjustment element is introduced that ensures implementation of the matching principle to the localization zones of the absorbed optical and electrostatic fields.