Optical waveguide and method for fabricating the same

摘要

The crosstalk characteristics of an arrayed waveguide grating or the like are improved. One or more of substrates are placed at a circumferential position centering the table rotational center C on a turntable that rotates at a constant angular speed of rotation omega and the turntable is rotated. A burner is moved to and fro in the radial direction of the turntable between positions r1 and r2 in the radial direction of the turntable and is reciprocated across the substrates. A material gas of glass, an oxygen gas and a hydrogen gas are passed through the burner to generate a hydrolysis reaction of the material gas in a hydrogen oxygen flame and an under cladding glass particle, a core glass particle and an over cladding particle are sequentially deposited on the substrates to form an optical waveguide part. The rotation velocity r1omega of the turntable at the position r1 is set 600 mm/sec or above at least in the step of depositing the core glass particle among the steps of depositing the under cladding glass particle, the core glass particle and the over cladding particle.