97 research outputs found
Magnetic field induced nutation of the exciton-polariton polarization in (Cd,Zn)Te crystals
We study the polarization dynamics of exciton-polaritons propagating in
sub-mm thick (Cd,Zn)Te bulk crystals using polarimetric time-of-flight
techniques. The application of a magnetic field in Faraday geometry leads to
synchronous temporal oscillations of all Stokes parameters of an initially
linearly or circularly polarized, spectrally broad optical pulse of 150 fs
duration propagating through the crystal. Strong dispersion for photon energies
close to the exciton resonance leads to stretching of the optical pulse to a
duration of 200300 ps and enhancement of magneto-optical effects such as the
Faraday rotation and the non-reciprocal birefringence. The oscillation
frequency of the exciton-polariton polarization increases with magnetic field
, reaching 10 GHz at T. Surprisingly, the relative contributions of
Faraday rotation and non-reciprocal birefringence undergo strong changes with
photon energy, which is attributed to a non-trivial spectral dependence of
Faraday rotation in the vicinity of the exciton resonance. This leads to
polarization nutation of the transmitted optical pulse in the time domain. The
results are well explained by a model that accounts for Faraday rotation and
magneto-spatial dispersion in zinc-blende crystals. We evaluate the exciton
-factor and the magneto-spatial constant eVcm.Comment: 11 pages, 6 figure
Properties of exchange coupled all-garnet magneto-optic thin film multilayer structures
The effects of exchange coupling on magnetic switching properties of all-garnet multilayer thin film structures are investigated. All-garnet structures are fabricated by sandwiching a magneto-soft material of composition type Bi1.8Lu1.2Fe3.6Al1.4O12 or Bi3Fe5O12:Dy2O3 in between two magneto-hard garnet material layers of composition type Bi2Dy1Fe4Ga1O12 or Bi2Dy1Fe4Ga1O12:Bi12O3. The fabricated RF magnetron sputtered exchange-coupled all-garnet multilayers demonstrate a very attractive combination of magnetic properties, and are of interest for emerging applications in optical sensors and isolators, ultrafast nanophotonics and magneto-plasmonics. An unconventional type of magnetic hysteresis behavior not observed previously in magnetic garnet thin films is reported and discussed
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Tailoring Light-Matter Interaction with a Nanoscale Plasmon Resonator
We propose and demonstrate a new approach for achieving enhanced light-matter interactions with quantum emitters. Our approach makes use of a plasmon resonator composed of defect-free, highly crystalline silver nanowires surrounded by patterned dielectric distributed Bragg reflectors. These resonators have an effective mode volume (Veff) 2 orders of magnitude below the diffraction limit and a quality factor (Q) approaching 100, enabling enhancement of spontaneous emission rates by a factor exceeding 75 at the cavity resonance. We also show that these resonators can be used to convert a broadband quantum emitter to a narrow-band single-photon source with color-selective emission enhancement.Physic
Tunable optical nanocavity of iron-garnet with a buried metal layer
We report on the fabrication and characterization of a novel magnetophotonic structure designed as iron garnet based magneto-optical nanoresonator cavity constrained by two noble metal mirrors. Since the iron garnet layer requires annealing at high temperatures, the fabrication process can be rather challenging. Special approaches for the protection of metal layers against oxidation and morphological changes along with a special plasma-assisted polishing of the iron garnet layer surface were used to achieve a 10-fold enhancement of the Faraday rotation angle (up to 10.8°=μm) within a special resonance peak of 12 nm (FWHM) linewidth at a wavelength of 772 nm, in the case of a resonator with two silver mirrors. These structures are promising for tunable nanophotonics applications, in particular, they can be used as magneto-optical (MO) metal-insulator-metal waveguides and modulators
Electron spin contrast of Purcell-enhanced nitrogen-vacancy ensembles in nanodiamonds
Nitrogen-vacancy centers in diamond allow for coherent spin state
manipulation at room temperature, which could bring dramatic advances to
nanoscale sensing and quantum information technology. We introduce a novel
method for the optical measurement of the spin contrast in dense
nitrogen-vacancy (NV) ensembles. This method brings a new insight into the
interplay between the spin contrast and fluorescence lifetime. We show that for
improving the spin readout sensitivity in NV ensembles, one should aim at
modifying the far field radiation pattern rather than enhancing the emission
rate
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