Using a quantum well heterostructure to study the longitudinal and transverse electric field components of a strongly focused laser beam

Abstract

We report a method to measure the electric energy density of longitudinal and transverse electric field components of strongly focused polarized laser beams. We used a quantum well photodetector and exploited the polarization dependent optical transitions of light holes and heavy holes to probe the electric field distribution in the focal region. A comparison of the measured photocurrent spectra for radially and azimuthally polarized beams at the light and heavy hole absorption peaks provides a measure of the amount of the longitudinal electric field component.

Exploiting cellophane birefringence to generate radially and azimuthally polarised vector beams

“…This longitudinal field has been confirmed in various publications [2][3][4][5][6][7][8][9], and a smaller spot size in comparison to a linearly polarised beam has been reported [2,3]. Because of those properties, radially polarised beams have found several applications in optical data storage [10] and laser machining [11,12].…”

Scanning metallic nanosphere microscopy for vectorial profiling of optical focal spots

“…A wide range of applications have been explored, which include optical trapping [2][3][4][5][6][7], laser cutting and drilling [8][9][10], optical imaging [11], surface plasmon excitation and focusing [12][13][14][15][16], Raman scattering [17,18], fluorescence [19], photothermal therapy [20], two photon absorption lithography [21], harmonics generation [22,23], optical data storage [24,25], unique beam shaping [26,27], etc. To obtain knowledge of the vectorial profiles of the focal spots, a variety of characterization methods have been demonstrated, which include scanning near-field optical microscopy (SNOM) [28][29][30][31][32][33], optical antennas [34,35], a campanile nanofocusing geometry [36,37], metallic nanoparticle scattering [38][39][40], molecular absorption [41], exposing photoresist [42], anisotropic absorption of quantum wells [43], and mathematical reconstruction [32,…”