Near-field mapping of quantum dot emission from single-photonic crystal cavity modes

Abstract

We directly investigate, by means of near-field spectroscopy, the spatial distribution of the optical cavity modes of 2D photonic crystal microcavities. Numerical simulations confirm that the photoluminescence maps of quantum dots embedded in the photonic structure qualitatively match the spatial modulation of the electric field intensity. r

Polarization-sensitive near-field investigation of photonic crystal microcavities

“…[3][4][5][6][7] In order to achieve a better spatial resolution, scanning near-field microscopy has already proved to be a powerful tool for addressing the optical modes of PC based devices. [8][9][10][11][12][13][14][15][16][17][18][19][20] Moreover, it was recently demonstrated that the spectral shift of the cavity modes induced by the local probe directly maps the electric field intensity, providing an additional imaging option with higher spatial resolution. [15][16][17][18] However, even if particular configurations of near-field optical microscopes allow to control the polarization properties of light 20,21 a direct correlation between the spatial map and the polarization of the electromagnetic modes of PC-MCs has not yet been obtained.…”

Spatially relocatable and spectrally tunable photonic crystal cavity by using a microsphere

“…PCs are composed of a periodic array of dielectric mediums with different refractive indices; they can manipulate the propagation of lights with a wavelength-scale structure. PC cavities have been applied to nanolasers, [1][2][3][4][5][6] optical switches, 7,8 and single-photon sources [9][10][11][12][13][14] because of their low optical loss and wavelength-sized mode volume, which enables strong light-matter interactions. In particular, the single-photon sources employed for quantum cryptology consist of a high quality factor (Q) PC cavity and a quantum dot (QD) as an atom-like emitter.…”

Coupling of single quantum dots to photonic crystal cavities investigated by low-temperature scanning near-field optical microscopy

“…The intensity collected by the tip is expected to map the modulus square of the in-plane electric field at the surface of the membrane. 18 Figures 3(b) and 3(d) show the modulus square of the in-plane electric field for modes M1 and M2, respectively, calculated using a 2D finite element software. The observed mode maps are clearly elongated along the two orthogonal axes of the cavity, in agreement with the calculation.…”

“…This gives an estimation of the spatial resolution of our SNOM images, as observed in room-temperature experiments. 18 However, since a generally accepted model for the IRF is not available, we consider only the calculated mode profile in the following. Additionally, in the present case of low-density QDs, where only one QD is present in the cavity, we expect that in the employed illumination-collection mode the pumping of the QD strongly depends on the tip position, producing substantial changes to the map.…”