We analyse recent experiments on momentum shearing interferometry of electron wave packets by using an optical analogy with shearing interferometry for optical waves. This analogy offers a convenient point of view to discuss the capabilities and difficulties of this technique used to access the phase of electron wave packets.
We present a study of time-resolved transmission and emission properties of optically anisotropic planar microcavity
structures. The structures consist of λ/4-layers of SiO<sub>2</sub> and TiO<sub>2</sub> for the dielectric mirrors and a cavity
layer of either SiO<sub>2</sub> or the organic dye composite AlQ<sub>3</sub>/DCM. For the SiO<sub>2</sub> cavity, we observe a polarization
splitting at normal incidence leading to terahertz oscillations of transmitted coherent light. The polarization
splitting is explained by an optical anisotropy of the dielectric layers caused by the fabrication process. We
apply an up-conversion setup for temporally and spectrally resolved transmission measurements and obtain a
corresponding beating of 1.25 THz. Time resolved measurements yield a Q-value of 1600, corresponding to a
cavity photon lifetime of 0.65 ps. We explain our observations with a transfer-matrix model and introduce a
Fourier-transform based analytical algorithm. The cavity filled with the organic dye composite can act as an
organic microcavity laser. The birefringence of the distributed Bragg reflectors leads to lasing in two perpendicularly
polarized modes. Investigations of the ultrafast dynamics of this laser system show a phase coupling
of the two laser modes leading to the generation of a terahertz optical beat. The oscillation frequency can be
widely tuned by variations in the fabrication process.
We report on the experimental observation of polarization splitting and terahertz oscillations in transmission and laser emission from optically anisotropic microcavities. A guest-host composite of tris-(8-hydroxyquinoline) aluminium (Alq3) and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) serves as active laser material. The anisotropy is attributed to oblique columnar structures in the distributed Bragg reflector mirrors of our microcavity, resulting from sample fabrication. A splitting of 0.2 nm occurs in the laser emission from an organic vertical cavity surface emitting laser at a wavelength of 612.6 nm, and a splitting of 2.5nm is obtained from a sample for Ti-Sapphire laser transmission at 781 nm. Split modes are perpendicularly polarized.
An upconversion setup allows temporally resolved studies of transmission and emission behavior, showing an oscillation at a frequency of 1.25THz in transmission, and 0.18THz in emission, respectively. The temporal behavior of laser emission is modelled by a set of rate-equations and extended to account for the resulting oscillations. Our observations suggest that a phase-coupling mechanism between both occuring modes is present in the laser emission from our microcavity.