Optical Tomography using Multiple Fan-Beam Projection Technique

Abstract

This paper presents the timing advantage of implementing multiple fan beam projection technique using optical fibre sensors for a tomography system. To prepare the optical fibre sensors to be used for this multiple fan beam projection, a collimator is not needed but optical fibre lens termination is crucial. In this research, the fibre optic lens for transmitters is modelled by experimental methods to transmit light at an emission angle of 30 degree. Due to its small emission angle, multi projection technique can be implemented without the lights overlapping. Multiple fan beam projection technique here is defined as allowing more than one emitter to project light at the same time using the switch mode fan beam method. This method used is able to increase the optical sensor’s ability in flow visualization. For the 32 pairs of sensors used, the 2 projection technique and 4 projection technique are being investigated. 16 sets of projections will complete one frame of light emission for the 2 projection technique while 8 sets of projection will complete one frame of light emission for the 4 projection technique. Compared to the conventional single light projection used in switch-mode fan beam method, multiple light projections can achieve a higher data acquisition rate, thus minimizing data lost and producing a more accurate real-time tomographic image.