Theoretical and Experimental Study of Optimization of Polarization Spectroscopy for the D2 Closed Transition Line of 87Rb Atoms

We experimentally and theoretically investigated the optimal condition of polarization spectroscopy for frequency stabilization on various pump beam intensities and vapor cell temperatures for the D2 closed transition line of 87Rb atoms. We compared the experimental results, such as the amplitude, width, and slope, of the polarization spectroscopy signal with the theoretical results obtained from the numerical calculation of temporal density matrix equations. Based on the results, we found the optimal parameters, such as the pump beam intensity and vapor cell temperature, for polarization spectroscopy. The theoretically expected optimal parameters were, qualitatively, in good agreement with the experimental results.

Расчет эффективности удвоения частоты излучения субтерагерцового гиротрона за счет решеточной нелинейности в монокристаллической пластине InP

In this work, we calculated the efficiency of second harmonic generation for sub-THz gyrotron radiation in a single-crystal InP plate embedded in a conical metal waveguide. For the values of the losses at the doubled frequency (depending on the degree of purity of the InP crystal), the dimensions of the wafer are revealed that provide the optimal effective frequency conversion. Thus, the conversion factor f –>2f can reach 5 W/kW^2 when pumped at a frequency of 263 GHz and a loss of alpha_2f = 0.1 cm^-1. The possibility of a noticeable increase in the efficiency of frequency doubling with fine tuning of the phase matching due to the selection of the size of the submicron gap between the InP plate and the plates of the metal waveguide is shown. The results obtained can be used to solve applied problems in the field of dynamic nuclear polarization spectroscopy and nuclear magnetic resonance studies.