| 摘要 |
PURPOSE:To provide the entirely novel KLN crystal fiber which is adequate for optical secondary harmonic generation by having a core layer and clad layer which are respectively specific. CONSTITUTION:This KLN crystal fiber is composed of the core 1 consisting of the KLN (potassium lithium niobate) and having a square section and the clad layer 2 covering the outer periphery of the core layer 1. The core layer 1 is formed by using a growth device which is provided with a melt drawing out port in the bottom of a growth cell of a resistance heating type and is inserted with a melt feeder in this melt drawing out port, by which the KLN crystal having an optically homogeneous tetragonal crystal is obtd. The clad layer 2 is formed of a low-loss optical material having the refractive index lower than the refractive index of the KLN crystal. The process for production of the clad layer 2 is exemplified by coating, extruding, CVD methods, etc. The light from a light source is kept held in nearly a condensing state over the range of the entire length if this optical fiber is used as a fiber for optical second harmonic generation. Since the interaction length is made sufficiently long, the high optical second harmonic generation efficiency is obtd. |
