| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a great number of spherical projections made of a metal semi-regularly arranged on the surface of the metal by irradiating the metal installed in a fixed vacuum atmosphere with a pulse laser beam. SOLUTION: A metal body 32 is preferably a single crystal of a low-melting metal such as W32, etc., W32 as the metal body 32 is held by a retaining holder 33 in a vacuum chamber 22. The vacuum chamber 22 is evacuated, a He gas is introduced from an inert gas inlet pipe 31 and the pressure in the vacuum chamber 22 is retained, for example, at 4kPa. Then a pulse laser beam L is oscillated at 1-1.2 j/P output at 8-10 ns pulse width at 1-20 Hz number of pulse repetition from Nd:YAG laser oscillator 23 of 1,064 nm wavelength, rotates a plane of polarization in a (λ/2) plate 24, condensed through refraction mirrors 25 and 27 by a condensing lens 28 to form a focus through an introduction window 29 on a W surface 32a. W fine projections are formed on the W surface 32a at 0-30 deg. irradiation angle at 300-1,200 times of number of irradiations.</p> |
