| 摘要 |
PURPOSE:To obtain a distributed index type flat plate microlens which is brighter than conventional lenses, by dipping the sample glass coated thereon with a mask consisting of two layers of Cr-Au in a molten salt bath, and diffusing thermally and selectively a dopant in the sample glass. CONSTITUTION:Thin films or Cr 11 and Au 12 are continuously deposited by vacuum evaporation on the surface of sample glass (e.g.; optical glass BK-7). A mask pattern 13 having a prescribed hole diameter is formed on the mask consisting of such thin films, then Au is etched with an I-Ki soln. and Cr with an aq. soln. consisting essentially of KOH, then the resist is stripped. The glass 10 in this state is floated in a molten salt bath 14 consisting of thallium sulfate, zinc sulfate, potassium sulfate and sodium sulfate in gaseous Ar flow, and is brought into reaction at, for example, 574 deg.C. After the glass 10 completed the reaction, the glass is slowly cooled, Au and Cr are successively removed by chemical etching; thereafter, the glass is optically polished, thereby the intended distributed index type flat plate microlens is obtd. |
