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تسجيل مستخدم جديدFrequency evaluation of collimated blue light generated by wave mixing in Rb vapour
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An evaluation of the absolute frequency and tunability of collimated blue light (CBL) generated in warm Rb vapour excited by low-power cw laser radiation at 780 nm and 776 nm, has been performed using a Fabry-Perot interferometer and a blue diode laser. For the conditions of our experiments the CBL tuning range is more than 100 MHz around the resonant frequency of the 85Rb 5S1/2 (F=3) to 6P3/2 (F=4) transition. A simple technique for stabilizing the power and frequency of the CBL to within a few percent and 10 MHz, respectively, is suggested and demonstrated.
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We present a study of the spectral linewidth of collimated blue light (CBL) that results from wave mixing of low-power cw laser radiation at 780 nm and 776 nm and an internally-generated mid-IR field at 5.23 um in Rb vapour. Using a high-finesse Fabr
y-Perot interferometer the spectral width of the CBL is found to be less than 1.3 MHz for a wide range of experimental conditions. We demonstrate that the CBL linewidth is mainly limited by the temporal coherence of the applied laser fields rather than the atom-light interaction itself. Results obtained with frequency modulated laser light allow an upper limit of several hundred kHz to be set for the linewidth of the collimated mid-IR radiation at 5.23 um, which has not been directly detected.
We present results of a study of four-wave mixing in Rb vapour with highly nonlinear susceptibility, using both homodyne and heterodyne detection. We demonstrate that the spectra have different appearances for media possessing electromagnetically ind
uced transparency and electromagnetically induced absorption, and for different relative polarizations of the drive and probe fields. We show that these differences allow the contributions of different processes responsible for the enhanced Kerr nonlinearity of the media to be distinguished.
We report the transfer of phase structure, and in particular of orbital angular momentum, from near-infrared pump light to blue light generated in a four-wave-mixing process in 85Rb vapour. The intensity and phase profile of the two pump lasers at 78
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Population inversion on the 5D-6P transition in Rb atoms produced by cw excitation at different wavelengths has been analysed by comparing the generated mid-IR radiation at 5.23 um originated from amplified spontaneous emission and isotropic blue flu
orescence at 420 nm. A novel method of detecting two-photon excitation in atomic vapours using ASE is suggested. We have observed directional co- and counter-propagating emission at 5.23 um. We find that the power dependencies of the backward- and forward-directed emission can be very close, however their spectral dependencies are not identical. The mid-IR emission in Rb vapours excited by nearly counter-propagating beams at 780 and 776 nm does not exactly coincide spatially with the applied laser beams. The presented observations could be useful for enhancing efficiency of frequency mixing processes and new field generation in atomic media.
We use a magnetometer probe based on the Zeeman shift of the rubidium resonant optical transition to explore the atomic magnetic response for a wide range of field values. We record optical spectra for fields from few tesla up to 60 tesla, the limit
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