Nanoscale resolution for fluorescence microscopy via adiabatic passage

Abstract

We propose the use of the subwavelength localization via adiabatic passage technique for fluorescence microscopy with nanoscale resolution in the far field. This technique uses a Λ-type medium coherently coupled to two laser pulses: the pump, with a node in its spatial profile, and the Stokes. The population of the Λ system is adiabatically transferred from one ground state to the other except at the node position, yielding a narrow population peak. This coherent localization allows fluorescence imaging with nanometer lateral resolution. We derive an analytical expression to asses the resolution and perform a comparison with the coherent population trapping and the stimulatedemission-depletion techniques.

Subwavelength-width optical tunnel junctions for ultracold atoms

“…The use of athree-level system to generate an optical potential in place of the typical two-level system offers more flexibility, because dark resonances [10] allow one to overcome the diffraction limit [11–21]. In this paper, building on previous studies of subwavelength-scale forces [22], atom localization [11–21,23–43], and non-dark-state-based techniques for building subwavelength potentials in the far field [44–55], we use the geometric scalar (Born-Huang) potential [56–58] experienced by spatially dependent dark states to create optical potential barriers with subwavelength widths. Our proposal has the advantage of not using lattice modulation, which could lead to heating, and of taking advantage of a feature—the geometric scalar potential—that naturally accompanies any subwavelength potential formed by spatially dependent dressed states.…”

Spatially strongly confined atomic excitation via two dimensional stimulated Raman adiabatic passage

“…Therefore, it can be also important for systems, where coherence has to be preserved, e.g., atomic Bose-Einstein condensates (BECs), or for applications to the quantum information science. We note, that while the STIRAP technique has already found a multitude of applications [23][24][25][26], thus far it has been rarely applied for high-precision atomic localization [14,27,28].…”

“…to generate qubits) [1][2][3][4], patterning of Bose-Einstein condensates (e.g., for applications in quantum information processing) [5,6], high-resolution imaging (e.g. labelling in two-photon fluorescence microscopy) [7,8], or optical lithography (e.g. by precisely localized excitations in a photoresist) [9].…”

“…Consequently, the spatial resolution of adiabatic excitation increases rapidly (much faster compared to the case of the incoherent excitation) with increasing the laser intensity, and is not limited by the diffraction. Spatially confined atomic excitation based on STIRAP is a fully coherent process that does not rely on the spontaneous emission, as the atoms adiabatically follow the dark state [14,27,28]. Therefore, it can be also important for systems, where coherence has to be preserved, e.g., atomic Bose-Einstein condensates (BECs), or for applications to the quantum information science.…”

“…It should be pointed out that a similar configuration has been employed in Ref. [28] with Stokes pulse having a Bessel beam spatial profile, and the one of the pump being the result of superimposing two Bessel beams focused with a lateral offset, producing a node in its center. On the other hand, in our scheme, the pump carries an OAM while the Stokes has no spatial dependence, creating a spot localization.…”