## Nomenclature  
\begin{tabular}{l l} Symbol & \\ \(\alpha\) & Angle of incidence \\ Se & Selenium \\ Cu & Copper \\ \(t\)-Se & Trigonal selenium \\ \(E_{\text{in}}\) & Laser pulse energy \\ \(R_{\text{in}}\) & Input impedance of the oscilloscope \\ \(j_{\text{x}}\) & Longitudinal photocurrent \\ \(j_{\text{y}}\) & Transverse photocurrent \\ \(U_{\text{x}}\) & Extreme values of the voltage pulses at the experimental geometry when the measuring electrodes were placed perpendicular to the plane of incidence \\ \(U_{\text{y}}\) & Extreme values of the voltage pulses at the experimental geometry when the measuring electrodes were placed parallel to the plane of incidence \\ \(t\) & Time \\ \(\eta_{\text{x}}\) & Efficiency of converting light into longitudinal photocurrent \\ \(\eta_{\text{y}}\) & Efficiency of converting light into transverse photocurrent \\ \(\Phi\) & Angle between the plane of polarization and the radiation incidence plane on the film \\ \(\sigma\) & Radiation incidence plane on the film \\ \(\mathbf{n}\) & Normal to the film surface \\ \(\mathbf{A}\) & Measuring electrode \\ \(\mathbf{B}\) & Measuring electrode \\ \(\mathbf{k}\) & The wave vector of the optical field \\ \(\mathbf{E}\) & Electric field vector of the incident radiation \\ \(\mathbf{E}^{(t)}\) & Electric field vector of the refracted beam \\ \(\mathbf{x},\mathbf{y}\) & Axes of the rectangular coordinate system \\ \(\mathbf{x}^{\prime}\) & Axis, which lies in the \(\sigma\) plane and perpendicular to \(\mathbf{k}\) \\ \(\mathbf{x}^{\prime\prime}\) & Axis, which lies in the refraction plane coinciding with the plane of incidence \\ \(t_{\text{p}}\) & Complex Fresnel refractive index for \(p\)-polarizations \\ \(t_{\text{s}}\) & Complex Fresnel refractive index for \(s\)-polarizations \\ \(\hat{n}\) & Complex refractive index \\ \(n\) & Real refractive index that determines the phase velocity \\ \(\kappa\) & Absorption coefficient \\ \(\delta_{\text{t}}\) & Phase shift between the components of the refracted beam with \(p\)- and \(s\)-polarizations \\ \(\delta_{\text{tp}}\) & Phase shift of the \(p\)-component of the beam, resulting from refraction at the interface \\ \(\delta_{\text{ts}}\) & Phase shift of the \(s\)-component of the beam, resulting from refraction at the interface \\  & between two media with a complex refractive index \\ \(\delta_{0}\) & Initial phase shift between the \(p\)- and \(s\)-components before refraction \\ \(a\) & Semi-major axis of the refracted beam polarization ellipse \\ \(b\) & Semi-minor axis of the refracted beam polarization ellipse \\ \(P_{\text{cir}}\) & Degree of circular polarization \\ \(P_{\text{lin}}\) & Degree of linear polarization \\ \(\psi\) & Angle between the semi-major axis of the refracted beam polarization ellipse and axis \(\mathbf{x}^{\prime\prime}\) \\ \(\gamma\) & Sign of circular polarization \\ \(U_{\text{y}}(t,\,\alpha)\) & Waveforms of the transverse photovoltage pulses \\ \(A_{\text{cir}}\) & Positive coefficient of the circular photocurrent at a given \(\alpha\) \\ \(A_{\text{lin}}\) & Positive coefficient of the linear photocurrent at a given \(\alpha\) \\ \(B_{\text{cir}}\) & Positive coefficient (for positive \(\alpha\)) depending on \(\alpha\) and characterizing the \\  & Circular contribution \\ \(B_{\text{lin}}\) & Positive coefficient (for positive \(\alpha\)) depending on \(\alpha\) and characterizing the \\  & linear contribution \\ \(f_{\text{cir}}(t)\) & Transverse photovoltage waveform normalized to its maximum value, recorded at angle \(\alpha\) close to zero for circular polarizations \\ \(f_{\text{lin}}(t)\) & Transverse photovoltage waveform normalized to its maximum values, recorded at angle \(\alpha\) close to zero for linear polarizations \\ \end{tabular}