M.Sc. Projects Multi-Media
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 Visualising Carrier Distribution and Optical Fields in VCSELs
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 Vertical Cavity Surface Emitting Lasers ( VCSELs ) are a 
 category of Semiconductor Lasers that have currently gained
 much prominence and are finding extensive, diverse applications 
 in, for example communication, data recording, sensing etc.
  
 The VCSELs are typcally of cylindrical symmetry but within 
 that overall feature various different structures have been 
 developed to try and achieve required device performance 
 characteristics. Clearly, the modelling of such devices is 
 essential to design for desired operation. The modelling 
 involves computing the optical (electromagnetic) fields
 self-consistently with the interacting carrier ( inversion 
 population ) distribution. Various stages of the model have 
 been developed ( in Fortran ) and can be used as needed.

 The general solutions that emerge from the model are often
 quite complex and are not that easy to visualise. The object
 of this project is to develop a capability for not only 3-D
 visualisation of the fields and the carrier distributions but
 also to conveniently enable 'observation' from different angles 
 (perspectives) so that the physical features may be 'understood'
 more readily. Consequently it is felt that such a capability 
 will enable better device designs to be conveniently suggested.
   
 The project student could programme in a Matlab environment, 
 which provides a superior graphics library for 3D visualisation 
 in Windows operating system. However, for one more familiar with 
 Fortran and Unix operating system the NAG Graphics Library can 
 be used to implement real-time visualisation of optical field 
 and carrier distribution. The graphics module can be readily 
 incorporated into the existing (device model) Fortran code in a
 Unix environment.

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 Recording Near-Fields of Semiconductor Optical Sources
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 Semiconductor LASERs and LEDs are based on optical guided wave
 structures with lateral dimensions typically of the order of a 
 micron(=10-4 cm). Experimental measurements of (near-field) optical 
 intensity profiles are needed to establish device characteristics. 
 Because of the small dimensions,the optical spatial profile is magnified 
 very significantly using a system of lenses before imaging it on
 to a vidicon (video camera). The vertical/horizontal scan outputs
 (electrical) from the vidicon provide the signals which then 
 digitised are fed in to a computer to generate the optical intensity 
 profiles.

 The main objective of this project is to develop an image scanning
 program in a Windows environment. The existing image capture card in 
 the PC connects to the video camera which has on it the magnified 
 intensity profile of the LASER/LED. The required functionalities of 
 the program will include the display of cross-sectional intensity profile, 
 2-D near-field patterns and 3-D visualisation of the optical field. The
 project student will be required to develop an image scanning program 
 under Windows environment using Visual BASIC or Visual C that will provide
 the above mentioned functionalities.