Complete Stokes vector analysis with a compact, portable rotating waveplate polarimeter.

Accurate calibration of polarization-dependent optical elements is often necessary in optics experiments. A versatile polarimeter device to measure the polarization state of light is a valuable tool in these experiments. Here, we report a rotating waveplate-based polarimeter capable of complete Stokes vector analysis of collimated light. Calibration of the device allows accurate measurements over a range of wavelengths, with a bandwidth of >30 nm in this implementation. A photo-interrupter trigger system supplies the phase information necessary for full determination of the Stokes vector. An Arduino microcontroller performs rapid analysis and displays the results on a liquid crystal display. The Arduino can also be interfaced with a computer to store time series of Stokes vectors. The optical measurement apparatus of the polarimeter is compact and can be placed anywhere on an optical table on a single standard post. The components to construct the device are only a fraction of the cost of commercially available devices, while the accuracy and precision of the measurements are of the same order of magnitude.

Resonance fluorescence from a coherently driven semiconductor quantum dot in a cavity.

We show that resonance fluorescence, i.e., the resonant emission of a coherently driven two-level system, can be realized with a semiconductor quantum dot. The dot is embedded in a planar optical microcavity and excited in a waveguide mode so as to discriminate its emission from residual laser scattering. The transition from the weak to the strong excitation regime is characterized by the emergence of oscillations in the first-order correlation function of the fluorescence, g(tau), as measured by interferometry. The measurements correspond to a Mollow triplet with a Rabi splitting of up to 13.3 microeV. Second-order correlation measurements further confirm nonclassical light emission.