Optical polarization

About: Optical polarization is a research topic. Over the lifetime, 13992 publications have been published within this topic receiving 244284 citations.

Optical heterodyne profilometry.

Abstract: A noncontact optical technique for the measurement of surface profile is described, which has a height sensitivity of the order of 1 A. It is based on a common path heterodyne interferometer in which two orthogonally polarized beams of slightly different frequency are focused on the surface to be measured. One focal point acts as a reference as the other point circularly scans the surface. The phase of the beat frequency of the interfering return beams is directly proportional to the surface height. The results of a surface measurement include graphical displays of the surface profile, autocovariance function, spectral density function, stability, and repeatability. Comparison with other instruments is also discussed.

Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s−1 directly modulated lasers and 40 Gb s−1 signal-regenerative amplifiers

Abstract: This paper presents recent progress in the field of semiconductor lasers and optical amplifiers with InAs-based self-assembled quantum dots in the active region for optical telecommunication. Based on our design in terms of the maximum bandwidth for high-speed modulation and p-type doping in quantum dots for high temperature stability, we realized temperature-insensitive 10 Gb s−1 laser diodes on a GaAs substrate at 1.3 µm. The output waveform at 10 Gb s−1 maintained a clear eye opening, average output power and extinction ratio without current adjustments from 20°C to 70°C. We developed ultrawide-band high-power amplifiers in the 1.5 µm wavelength region on an InP substrate. The amplifier showed ultrafast gain response under gain saturation, and enabled signal regeneration at 40 Gb s−1 by suppressing the '1'-level noise due to the beating between the signal and amplified spontaneous emission. We present our amplifier module with polarization diversity to enable a stable polarization-insensitive performance, and also, discuss prospects for polarization-insensitive quantum dots by the close stacking technique.

Mueller matrix decomposition for extraction of individual polarization parameters from complex turbid media exhibiting multiple scattering, optical activity, and linear birefringence

Abstract: Linear birefringence and optical activity are two common optical polarization effects present in biological tissue, and determi- nation of these properties has useful biomedical applications. How- ever, measurement and unique interpretation of these parameters in tissue is hindered by strong multiple scattering effects and by the fact that these and other polarization effects are often present simulta- neously. We have investigated the efficacy of a Mueller matrix decom- position methodology to extract the individual intrinsic polarimetry characteristics linear retardance and optical rotation , in particu- lar from a multiply scattering medium exhibiting simultaneous linear birefringence and optical activity. In the experimental studies, a pho- toelastic modulation polarimeter was used to record Mueller matrices from polyacrylamide phantoms having strain-induced birefringence, sucrose-induced optical activity, and polystyrene microspheres- induced scattering. Decomposition of the Mueller matrices recorded in the forward detection geometry from these phantoms with con- trolled polarization properties yielded reasonable estimates for and parameters. The confounding effects of scattering, the propagation path of multiple scattered photons, and detection geometry on the estimated values for and were further investigated using polarization-sensitive Monte Carlo simulations. The results show that in the forward detection geometry, the effects of scattering induced linear retardance and diattenuation are weak, and the decomposition of the Mueller matrix can retrieve the intrinsic values for and with reasonable accuracy. The ability of this approach to extract the indi- vidual intrinsic polarimetry characteristics should prove valuable in diagnostic photomedicine, for example, in quantifying the small opti- cal rotations due to the presence of glucose in tissue and for monitor- ing changes in tissue birefringence as a signature of tissue abnormality. © 2008 Society of Photo-Optical Instrumentation Engineers. DOI: 10.1117/1.2960934

Electronic structure of the negatively charged silicon-vacancy center in diamond

Abstract: The negatively charged silicon-vacancy (SiV${}^{\ensuremath{-}}$) center in diamond is a promising single-photon source for quantum communications and information processing. However, the center's implementation in such quantum technologies is hindered by contention surrounding its fundamental properties. Here we present optical polarization measurements of single centers in bulk diamond that resolve this state of contention and establish that the center has a $\ensuremath{\langle}111\ensuremath{\rangle}$ aligned split-vacancy structure with ${\mathrm{D}}_{3\mathrm{d}}$ symmetry. Furthermore, we identify an additional electronic level and evidence for the presence of dynamic Jahn-Teller effects in the center's 738-nm optical resonance.

Faraday-Rotation Measurements of Megagauss Magnetic Fields in Laser-Produced Plasmas

Abstract: Magnetic fields in the megagauss range have been observed in the laser-produced plasma near the focus of a high-power laser pulse. Faraday-rotation measurements utilizing the light of a probing beam and the specularly reflected laser light both show the presence of these large fields.