Dark-line atomic resonances in submillimeter structures

Abstract

We present measurements of dark-line resonances excited in cesium atoms confined in submillimeter cells with a buffer gas. The width and contrast of the resonances were measured for cell lengths as low as 100 microm. The measured atomic Q factors are reduced in small cells because of frequent collisions of atoms with the cell walls. However, the contrast of coherent population trapping resonances measured in the small cells is similar in magnitude to that obtained in centimeter-sized cells, but substantially more laser intensity is needed to excite the resonance fully when increased buffer-gas pressure is used. The effect of the higher intensity on the linewidth is reduced because the intensity broadening rate decreases with buffer-gas pressure.

Microfabricated atomic frequency references

“…Theoretical estimates based on diffusion in a buffer gas and complete depolarization on wall collisions indicate that a linewidth of near 1 kHz should be possible in a cell with dimensions of about 1 mm [11]. Experimental measurements confirm these predictions [12].…”

Atomic frequency references based on dark resonances in micrometric thin cells

“…Also shown in Fig. 2 are several values of Q buff in buffered cells extracted from the literature [1,3,4]. The contrast of CPTR in buffered cells is usually reduced by the collisional mixing and Doppler broadening of the excited state hyperfine structure.…”

Dark-Line Atomic Resonances in Micrometric Rb-Vapor Layer

“…Compact frequency references become increasingly important for many applications in recent years [1]. We present measurements of dark-line resonances excited in Rb atomic vapor confined in micrometric cells (MC).…”

“…As the size of the vapor cell is reduced, the lifetime of the ground-state coherence becomes shorter because of collisions of the atoms with the cell windows. Hence, in the case of MC one could expect that the effect of electromagnetically induced transparency (EIT) will vanish (note, that neither an additional buffer gas [1] nor paraffin coating has been used). Nevertheless, it was predicted in [2] that even in the case of pure vapor a narrow EIT resonance can be observed.…”