Double axis X-Ray rocking curves simulation

Abstract

Double axis X-ray diffraction has been in use since 1920. Recently the layer structures of optoelectronic devices have been characterised to control the optical properties, for the purpose of optical communication. By the advent of modern fast computers it is now possible to simulate experimental data. Here various techniques used for calculating double axis x-ray rocking curves are described. Mismatch, tilt, and composition of layers, can be quickly deduced by simulation. This approach has been widely used in the electronics industry. Recently it has been observed that a peak shift in the active layer of a double heterostructure could lead to a miscalculation of mismatch. An investigation in this direction was made to check this effect in the active layer of a double heterostructure laser. By comparing experimental and simulated data it has been observed that a shift occurs in the active layer peak and it appears that the calculated thickness is 0.018 µ m instead of 0.016 µ m of active layer of the laser. It is suggested that this peak shift could be studied in graded and multiple layer structures. The interactive part of SARCA programme which is a modification of CURVES programme needed changes to accept data for reflection (h,k,l) and accept data of material for entry of mixed mode of letters, to avoid unnecessary consumption of time. For this purpose two programmes in Pascal have been written. There is also much possibility of modelling double axis x-ray diffraction rocking curve profiles