A Research Grade Computer Controlled Light Source

The field of measurement and control is rapidly expanding which has given rise to the use of optical fiber sensors. These sensors offer various advantages over conventional sensors. The optical sources made by converting electrical energy into optical (light) energy play very important role in optical fiber sensing systems. Different experiments need to be performed with optical fibers to study their sensitivity and usefulness in numerous applications. The response of the optical fibers can be evaluated under various conditions of light sources such as variations in wavelength of light and its intensity. In case of distributed sensing systems, the light is sent in the form of pulses hence the width and the frequency of these light pulses also need to be controlled. This paper describes a research grade computer controlled light source which has been developed for research work in the field of optical fiber instrumentation. This system employs an integration of hardware and software. The Graphical User Interface (GUI) has been developed using Scilab to enter the required parameters of the light source. The hardware system is designed to utilize these parameters and give the light output as desired by the user. The parameters controlled by this system are light intensity, wavelength, duration, and the frequency of light pulses. The basic light sources that can be used for this purpose are Light Emitting Diodes (LED), LASERS or other sources of light. The wide range of variation in various parameters of the light produced by this system and also its cost effectiveness provides an important way for carrying out the research work in the field of optical fiber instrumentation and measurement.