Volume 91, Issue 8, 15 April 2002
Index of content:
- LASERS, OPTICS, AND OPTOELECTRONICS (PACS 42)
91(2002); http://dx.doi.org/10.1063/1.1454199View Description Hide Description
Photonic crystal waveguides including resonant cavities have been fabricated and investigated by transmission spectroscopy. The waveguides consist of two missing rows in a triangular lattice of air holes in a GaAs/AlGaAs slab–waveguide structure. The mirrors of the cavities are formed by adding two rows of holes perpendicular to the guiding direction inside the waveguide. The spectrally broad photoluminescence of an InAs quantum dot layer in the heterostructure is used to probe the transmission. Depending on the resonator size, characteristic resonant peaks are observed in the transmission spectra. Finite difference time domain calculations of the transmission of the investigated structures show good agreement with experimental data.
91(2002); http://dx.doi.org/10.1063/1.1459614View Description Hide Description
The formation dynamics of reflective holographicpolymer dispersed liquid crystals (H-PDLCs) is investigated with in situ spectroscopy. A modified diffusion model is proposed to describe the time dependent shrinkage of the polymer matrix during formation. The relationship between polymer shrinkage and functionality in H-PDLC systems is found to be linear.
91(2002); http://dx.doi.org/10.1063/1.1464208View Description Hide Description
A method is described for the design and realization of quantum-well (QW) structures optimized in respect to gain in optically pumped intersubband lasers. It relies on finding the optimal smooth potential (QW profile) by employing supersymmetric quantum mechanics, and then using the simulated annealing method to design a suitable QW structure with a small number of layers of different composition, such that it delivers the closest approximate to the optimal smooth profile after the interdiffusion process. This route towards achieving optimal QW profiles should be much easier to apply than a direct modulation of material composition at time of growing the structure.