الفهرس 
Cover EnglishOnly 14 pages are availabe for public view
 |  | from | 195 |  |  |
| | | from | 195 | | |
Abstract
Micromachining is a rapidly progressing to meet the requirements of high technology. High power Laser beam is nowadays one of the most interesting tool for micromachining because of :- Good quality High resolution High precision High processing speeds Low thermal damage Excellent reproducibility Use with many materials High production yields Good tolerances Single-stage “dry” process High flexibility Economically attractive The present work aims to introduce a home made system for micromachining based on near IR diode Laser consists of :- Diode laser of power 0-50 W, wave length range of 780-1000 nm which can operate in cw mode as well as pulsed mode. Driver controlling the power of the diode laser by varying the current in the range 8-60A as well as temperature to change the wave length. Mechanical system based on x-y stage “600 micro meters/step”, two steeper motors with step of controlled by advanced electronics system and the required software. The system cone be move either the sample on the stage or the focusing optics and the fiber deliver the laser beam according to the application. Abstract Evaluation of a home made micro- machining diode laser system iii Focusing and delivery system which allow the variation of the focus which is required for marking in glasses. Interface and software allowing to run the system using only one computer. The introduced here results shown the efficiency of the system for machining on: metal semiconductor and insulators. Black Carbon coating could be used for surfaces having high reflection to the used wavelength. A comparison was made with:- 1) short laser pulses obtained from ArF, XeCl Eximer laser of wavelength 193 and 308 nm, 6ns pulse duration, 200 Hz repetition rate and energy per pulse up to 13 mJ. 2- Ti- sapphire femtosecond laser ultra short laser pulses in the near infra red region of repetition rate of 82 MHz, energy per pulse 0-20 nJ with average power up to 800 mw. where in these two cases, High precision, high resolution ( 2 micrometer per step) mechanical stage were designed here controlled with a software allow synchronization with triggering the laser pulses in each case. Also CCD camera allow the monitoring of the micromachining process The introduced three system The comparison included cw and pulsed laser with the same wave length (NIR) as well different wave length NIR and UV. We designed a home made system for micromachining based on a diode laser. Micro marking was performed on copper, hard steel, wood, cartoon, and semiconductor using this system Comparison between the cw diode laser used in this system with short laser pulses in the UV and ultra short pulses in the IR was performed.A special design for optics and mechanical motion was given here. Evaluation of a home made micro- machining diode laser system iv Using the three systems we could fabricate diffraction grating of resolution up to 300 grove/mm. As well as we could made 6 holes in a human hair of a diameter around 8 micrometers. Finally the proposed here home made system for micro machining proved to give acceptable quality for insulators, metals and semiconductor as compared with two other systems with cheaper components in addition to the possibility of making this system portable.