Spatially resolved near-field spectroscopy on localized GaInAsP/InP double heterostructures

Abstract

We present investigations of band-gap variations on selective grown GaxIn1−xAsyP1−y multiple quantum wells (MQW, Q1.05) using near-field optical microscopy. The MQW is excited with the near-field probe and the luminescence is collected through the same tip. By this mode, we are able to detect variation of the band gap with a lateral resolution of about 550 nm at a luminescence wavelength of 1115 nm. We show a spatial band-gap modulation near the (0–11) facet of the selective grown structures, which we suggest, is a result of a variation of the material composition. Furthermore, together with the simultaneously recorded topography, we are able to allocate a recombination path at a center wavelength of λ=1115 nm to the intersection of the (01–1) and (11–1) vertical side facets, which are formed by interfacet diffusion during surface selective growth of the GaxIn1−xAsyP1−y MQW.

Multicolor images acquisition by scanning near-field optical microscopy

“…Up to now, a wide range of sample properties has already been studied by SNOM and has helped for the understanding of optical contrast mechanisms in the nanometer range. Measurements on semiconductors, 6,7 absorption and polarization changes on metallic and polymer samples have been performed. 8 SNOM with fluorescence detection is a suitable technique for single molecules and living cells detection [9][10][11][12][13][14] as it provides high sensitivity, high resolution and fast time acquisition as well.…”

Nanophotonics: Interactions, Materials, and Applications

“…With PSTM, a nanoscopic probe senses the evanescent field above a sample that is illuminated under total internal reflection. The optical processes detected by NSOM and PSTM involve both a propagating field (also called allowed light which has its wave vector real) and an evanescent field (also called forbidden light where the wave vector is imaginary). − However, most efforts related to NSOM and PSTM have concentrated on linear optical effects, − the area of nonlinear optical interactions at nanometer scale is still virtually unexplored. − The latter is the focus of work being conducted in our laboratory.…”

“…The optical processes detected by NSOM and PSTM involve both a propagating field (also called allowed light which has its wave vector real) and an evanescent field (also called forbidden light where the wave vector is imaginary). [13][14][15] However, most efforts related to NSOM and PSTM have concentrated on linear optical effects, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] the area of nonlinear optical interactions at nanometer scale is still virtually unexplored. [35][36][37][38][39][40][41][42][43][44] The latter is the focus of work being conducted in our laboratory.…”