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Abstrak :
A concept of phase space is usable to evaluate the characteristics of various components in microoptics engineering. In this study, a microoptical branching circuit by the use of three identical micro lenses has been constructed, for the purpose of dividing an input light beam into two outputs transmission and reflection beams, respectively. Mode distribution of input and output beams is, represented by using phase space configuration. By computer simulation, the concept of phase space has been used to predict mode conversion of light guiding in the circuit. The purpose of the study is to investigate the mode property in each element of the circuit, by measuring the far field mode distribution of the guided light. The existence of mode conversion in a particular element can be observed from the change of the respective made distribution. The experimental result shows a good agreement with that obtained by simulation of light guiding. It is concluded that, phase space representation derived from ray optics can be utilized as a software in analysis of wave guiding.

Abstrak :
A fluorescence spectrometer, with gating PMT (Photo Multiplier Tube) has been designed and constructed for the observation of Time Resolved Spectroscopy. Employed as a source far the fluorescence spectrometer a pulsed N2 lasers with about 5-nanosecond pulse width and 400-kilowatt power. Gating PMT carries out the sampling. In this method some of the dynodes of the PMT are being biased at voltages below normal operating voltage, while the other dynodes are held at their normal voltages. Sampling pulses generated by avalanche transistor are fed into the dynodes of the lower voltage to operate the PMT. A variable delay circuit of the order of nanosecond with respect to the N2 lasers pulse delays the sampling pulses. The output of the PMT is read on an oscilloscope and the lifetime of the fluorescence can be obtained by plotting the output of the PMT vs. the delay time.

Abstrak :
In detection of breast cancer using mammography, accurate diagnosis often depends on the visibility of small low contrast objects within the breast image. This is even more critical in the case of small tumor detection at early stage. Radiographic examination including mammography, have reduced the contrast and visibility of small objects. Due to the high X-ray penetration of the objects scattered radiation, and the limited capability of the film to develop maximum contrast over an extended range of exposure values. Density slicing method based on the interval setting of image histogram has been applied for the image enhancement and "quick classification". But for mammography it is also required to detect and identify the disease region clearly in order to decide a proper treatment. By using clustering method it was obtained some classes as training areas for the supervised classification and by selection of the operators of image enhancement the best boundaries of tissues had been detected. Finally by using the NGLDM (Neighboring Grey Level Dependence Matrix) method, the textural features of several diseases has also been extracted. From the experimental results that were obtained in this study, a simpler technique for accurate diagnostic has been yielded without increasing the dose of X-ray on patient or without any other psychological effects.