Unified circuit model for the polysilicon TFT

This paper proposes two methods to improve the modelling of thin film transistors (TFTs). The first involves integrating Poissons equation numerically, given a density of trap states and other relevant material parameters including a constant mobility. Theresult is conductance as a numerical function of gate voltage. The second method recognizes that the data for areal conductance found by numerical integration, may easily be found by measurement without making assumptions about the density of trap states.

Mode control in vertical-cavity surface-emitting lasers by post-processing using focused ion-beaih etching

Single-mode emission is achieved in previously multimode gain-guided vertical-cavity surface-emitting lasers (VCSEL's) by localized modification of the mirror reflectivity using focused ion-beam etching. Reflectivity engineering is also demonstrated to suppress transverse mode emission in an oxide-confined device, reducing the spectral width from 1.2 nm to less than 0.5 nm.

Three band-gap QW intermixing in InP/InGaAs/InGaAsP system for monolithically integrated optical switch

Quantum well intermixing is a key technique for photonic integration. The intermixing of InP/InGaAs/InGaAsP material involving the deposition of a layer of sputtered SiO2 on the semiconductor surface, followed by thermal annealing has allowed good control of the intermixing process and has been used to fabricate extended cavity lasers. This will be used for optimization of the performance of optical switches consisting of passive components, modulators and amplifiers.