Abstract: In a first embodiment, the invention makes use of a Neodymium doped YAG (Nd:YAG) gain medium placed in an optical resonant cavity formed by two mirrors. Power extraction is maximized for a specific laser cavity. In particular the concave curvature on the rod ends contributes a negative lensing component to modify the strength of the thermal lens. In a second embodiment the present invention uses an amplifier rod medium with curved ends to act as lensing elements to collect emission from the laser gain medium and/or oscillator described in the first embodiment of the invention. The combination of thermal lens and curved rod ends produces a lensing effect which allows light to be directly coupled from a laser. In addition, variation of the input pump power allows for control of the thermal lens formed within the amplifier rod.

Abstract: A laser processing method establishes initial coupling between the laser beam and workpiece by irradiating an intermediate tool positioned adjacent the workpiece. The tool is more absorptive at the laser wavelength than the workpiece so that the efficiency of energy transfer is increased. Subsequent processing is performed by relative movement between the workpiece and beam, either independently of the tool or in conjunction with the tool. During further processing, the beam diameter is increased to be greater than the thickness of the workpiece to enhance the further processing.

Abstract: There is provided a method and apparatus for controlling, in real-time, processing variables in laser processing of materials using fuzzy logic control procedures by embedding expertise in the form of a rule base within a fuzzy logic controller. The method uses a visible light detector as part of the control loop to detect light from the laser-material interaction zone. The light is processed to extract spatial information on the size of the interaction zone and in one aspect determines the number of bright pixels above a pre-defined number which effectively gives the spatial extent or area of the visible light emitted from the interaction zone. From this elemental processing two system input variables are obtained, namely the current number of bright pixels, #BP, and the change in this count since the last calculation, .DELTA.BP.

Abstract: There is provided a method and apparatus for controlling, in real-time, processing variables in laser processing of materials using fuzzy logic control procedures by embedding expertise in the form of a rule base within a fuzzy logic controller. The method uses a visible light detector as part of the control loop to detect light from the laser-material interaction zone. The light is processed to extract spatial information on the size of the interaction zone and in one aspect determines the number of bright pixels above a pre-defined number which effectively gives the spatial extent or area of the visible light emitted from the interaction zone. From this elemental processing two system input variables are obtained, namely the current number of bright pixels, #BP, and the change in this count since the last calculation, .DELTA.BP.

Abstract: An artificial cornea for sensing and integrating UV radiation in real time. The cornea includes an EPROM array adapted to be exposed to UV radiation. Individual bits of the EPROM array are set prior to being exposed to the UV radiation. In response to being exposed to the UV radiation predetermined ones of the individual bits are erased. Means for monitoring, in real time, the locations of the predetermined erased bits are provided and, in response, a record is formed of the energy distribution of the UV radiation across the EPROM array.