| 摘要 |
PURPOSE:To simply and easily decide the manufacturing conditions of an optical circuit element by fixing the refractive index of a turnout angle base plate, equivalent refractive index difference between the base plate and waveguides, and value of the equivalent standardized propagation constants of the base plate and waveguides so that the straight advancing state of light can be obtained with crosstalk lower than a specific dB. CONSTITUTION:This optical circuit element is a branch type optical circuit element provided with input-side waveguides 14a and 16a and output-side waveguides 14b and 16b forming at least a set of straight propagating routes of light on a base plate 12. Then values of the branched angle PSI, refractive index ns of the base plate, equivalent refractive index difference DELTAneff between the base plate and waveguides, standardized propagation constant (b) obtained by a equivalent refractive index method, which is equal to the standardized propagation constant of the waveguides for the basic mode, and standardized frequency V obtained by the equivalent refractive index method are decided so that the straight advancing state of light can be obtained at crosstalk of 3dB. Therefore, the manufacturing conditions of this optical circuit element can be decided easily and simply. |
