SPATIAL SEPARATION OF POLARIZATION COMPONENTS BY NONLINEAR BEAM RESHAPING IN A J=1 TO J=0 MEDIUM

1992 ◽  
Vol 01 (02) ◽  
pp. 393-420 ◽  
Author(s):  
R.J. BALLAGH ◽  
A.W. McCORD
Keyword(s):  
Optical Pumping ◽  
Polarized Light ◽  
Spatial Separation ◽  
Longitudinal Optical ◽  
Zero Field ◽  
Nonlinear Beam ◽  
Circularly Polarized Light ◽  
Polarized Beam ◽  
Light Beams ◽  
Elliptically Polarized

The diffractive reshaping that circularly polarized light beams undergo when coupled in a medium of homogenously broadened J=1→J=0 atoms is shown to be sensitively dependent on applied magnetic fields. In zero field, an elliptically polarized beam will retain its polarization everywhere in space, but a small longitudinal magnetic field can cause the beam to break up into spatially distinct regions of pure circular polarization. The beam behavior can be understood in terms of an encoding/diffraction sequence. An analytic solution for the atomic response function reveals the important roles played by transverse and longitudinal optical pumping.

Optical Pumping and Optical Detection of Spin-Polarized Electrons in a Conduction Band

1971 ◽  
Vol 49 (14) ◽  
pp. 1850-1860 ◽  
Author(s):  
R. R. Parsons
Keyword(s):  
Magnetic Field ◽  
Conduction Band ◽  
Spin Polarization ◽  
Optical Pumping ◽  
Polarized Light ◽  
Degree Of Polarization ◽  
Polarized Electrons ◽  
Excitation Light ◽  
Circularly Polarized Light ◽  
Spin Polarized

Spin-polarized electrons are created in the conduction band of p-type GaSb by excitation with σ+ or σ− circularly polarized light. The degree of polarization of the photoluminescence is used to measure the optically pumped spin polarization. The measurements as a function of transverse magnetic field yield the spin-relaxation time and the lifetime of the photocreated electrons. The degree of polarization oscillates as a function of the photon energy of the excitation light. This effect is associated with mechanisms of rapid energy loss involving optical and acoustical phonons. The optical pumping is studied as a function of temperature in the range 3.5 °K ≤ T ≤ 11 °K. A maximum spin polarization [Formula: see text] is obtained at [Formula: see text]. The efficiency of the optical pumping is significantly increased with the application of a weak longitudinal magnetic field.

SPIN-RESOLVED MAGNETO-OPTICAL STUDY OF CdSe SINGLE QUANTUM DOT

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1549-1554
Author(s):  
Zhanghai Chen ◽  
L. H. Bai ◽  
S. H. Huang ◽  
H. Xiong ◽  
S. C. Shen ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Polarized Light ◽  
Zero Field ◽  
Optical Study ◽  
Zero Field Splitting ◽  
Circularly Polarized Light ◽  
Exciton Lifetime ◽  
Luminescence Peak ◽  
Anisotropic Exchange Interaction ◽  
Anisotropic Exchange

We report on the magneto-optical study of spin polarized energetic fine structures for exciton complex in single CdSe quantum dot (QD) by using micro- photoluminescence (micro-PL) spectroscopy. The zero-field splitting of exciton luminescence peak arisen from the anisotropic exchange interaction of carriers in the QDs was observed. The g-factors for exciton and negatively-charged exciton, i.e. trion in a single QD were determined by fitting the magnetic field dependence of the corresponding PL peaks. By exciting the single QD with circularly polarized light of σ- and σ+ polarization, the spin-up and spin-down trions were selectively generated. The ratio, τ/τsf, of the exciton lifetime and the time constants for the spin-flipping process of trion in a single QD was estimated to be 0.13, which implies a long spin-lifetime in single CdSe QD.

scholarly journals Lateral forces on circularly polarizable particles near a surface

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Francisco J. Rodríguez-Fortuño ◽  
Nader Engheta ◽  
Alejandro Martínez ◽  
Anatoly V. Zayats
Keyword(s):  
Light Propagation ◽  
Polarized Light ◽  
Optical Force ◽  
Optical Forces ◽  
Circularly Polarized Light ◽  
Force Direction ◽  
Electromagnetic Momentum ◽  
Nanophotonic Structures ◽  
And Control ◽  
Light Beams

Abstract Optical forces allow manipulation of small particles and control of nanophotonic structures with light beams. While some techniques rely on structured light to move particles using field intensity gradients, acting locally, other optical forces can ‘push’ particles on a wide area of illumination but only in the direction of light propagation. Here we show that spin–orbit coupling, when the spin of the incident circularly polarized light is converted into lateral electromagnetic momentum, leads to a lateral optical force acting on particles placed above a substrate, associated with a recoil mechanical force. This counterintuitive force acts in a direction in which the illumination has neither a field gradient nor propagation. The force direction is switchable with the polarization of uniform, plane wave illumination, and its magnitude is comparable to other optical forces.

Lifetime of the 5p2P1/2 Level of Ionized Strontium

1974 ◽  
Vol 52 (17) ◽  
pp. 1666-1668 ◽  
Author(s):  
F. M. Kelly ◽  
T. K. Koh ◽  
M. S. Mathur
Keyword(s):  
Oscillator Strength ◽  
Ground State ◽  
Polarized Light ◽  
Optical Excitation ◽  
Zero Field ◽  
Level Crossing ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Field Level ◽  
Hanle Effect

The lifetime of the 5p2P1/2 level of Sr+ has been measured using the Hanle effect, or zero field level crossing technique, with optical excitation from the ground state of the ion. Circularly polarized light is used in the excitation and analysis. The ions are produced in a discharge at the mouth of the furnace used to produce a beam of strontium atoms. No foreign gas is used to carry the discharge. The oscillator strength of the 4215 Å, 5s2S1/2–5p2P1/2 transition is discussed.

The Analysis of the Experiment of Polarized Light in Uniaxial Dichroism Crystal

2013 ◽  
Vol 300-301 ◽  
pp. 1267-1270
Author(s):  
Nan Yang Ye ◽  
Da Hai Han
Keyword(s):  
Distribution Function ◽  
Light Intensity ◽  
Intensity Distribution ◽  
Polarized Light ◽  
Light Intensity Distribution ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Elliptically Polarized Light ◽  
Polarization Of Light ◽  
Elliptically Polarized

In the experiment of the polarization of light, circularly polarized light can’t be got though all instruments are carefully adjusted and the polarized light we get is generally regarded as elliptically polarized light. We analyzed the process and find the light we get isn’t circularly polarized light or elliptically polarized light as usually thought and deduced the light intensity distribution function and it can fit the experimental results with small errors.

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