| 摘要 |
<p>1,057,191. Removing metal by lasers. GENERAL ELECTRIC CO. March 23, 1964 [April 1, 1963], No. 12219/64. Heading B3V. [Also in Divisions B4 and G2] Apparatus for drilling small holes in material 21, Fig. 1, such as tungsten, molybdenum or platinum by focusing thereon a pulsed laser beam comprises a housing 1 having a reflective inner surface and an aperture 3 and containing a laser rod 4 and a flash lamp 5, a limiting aperture 22 and a reflecting objective lens 18, the material 21 being held in an adjustable member 24 for positioning the material at a selected distance from the focal point of the objective lens 18 and the lamp 5 being connected to a capacitor D.C. power supply circuit 7 and having wound thereon a wire 12 connected to an energizing circuit 13. A totally reflective prism, e.g. a Porro prism may be coupled to the end of the rod 4 to obtain a better collimated beam of light. The prism may be positioned externally of the housing 1 or be ground on the end 6 of the rod 4 and oriented correctly relative to the crystallographic C-axis. Circuit 7 comprises a D.C. power supply 8, Fig. 2, a resistor 9, capacitors 10 and inductances 11. Circuit 13, Fig. 2, comprises a battery 14, push-button switch 15 and step-up transformer 16. Objective lens 18 comprises convex mirror 19 and a concentric concave mirror 20. Aperture 22 is formed by an apertured white paper sheet. Objective lens 26 of microscope 25 is focused on material 21 to determine the focal point of objective lens 18. The microscope may also be used to obtain a precise transverse adjustment of material 21 relative to the axis of the laser beam. An auto-collimator 27 incorporating a partially reflective mirror 30 is employed to align the axis of objective lens 18 with the axis of the laser beam. Opaque and transparent shields 31, 32 are provided to protect the objective lenses 26 and 18 respectively. A diverging lens 33 is provided to prevent the centre of the laser beam from impinging on the centre of the reflecting surface of the mirror 19. Objective lens 18 and aperture 22 are mounted on an adjustable microscope body 23. As shown, the reflective inner surface of the housing 1 is ellipsoidal with the rod 4 and lamp 5 disposed at the respective foci thereof; alternatively, the reflective inner surface of the housing may be cylindrical with helical flash lamps 5 surrounding the rod 4.</p> |
