| 摘要 |
PURPOSE:To provide the mode conversion circuit for connecting optical circuits of different mode diameters by constituting an electric oven for locally heating the end face of a glass optical waveguide with a heater for heating, a heat shielding slit and a holder provided with a cooling mechanism. CONSTITUTION:The holder 7a with the cooling mechanism holds the quartz optical waveguide 4a and cooling water for circulation can be introduced therein. The electric oven for locally heating the end face of the quartz optical waveguide 4a is constituted of the heater 5a for heating, such as carbon heater, the heat shielding slit 6a and the holder 7a with the cooling mechanism. While the one end face of the quartz optical waveguide 4a is locally heated by the heater 5a for heating, the opposite side is cooled, by which a temp. gradient is forcibly formed within the optical waveguide 4a and the mode conversion (expansion) circuit is produced by the heat diffusion of the dopant in the core. As a result, the mode conversion circuit necessary at the time of connecting the optical circuits of the different mode diameters to each other or the optical waveguide of the small mode diameter to an optical fiber is well obtd. |
