| 摘要 |
PURPOSE:To obtain an interference type light guide which is reversibly controllable so as to obtain desired interference effects by providing a deforming means which deforms the light guide. CONSTITUTION:Two optical multiplexing and demultiplexing parts 8 and 9 whose core parts are close to each other are formed between incidence openings 6a and 7a and projection openings 6c and 7c and phase control parts 6b and 7b whose core parts are isolated from each other are formed between those multiplexing and demultiplexing parts. Those optical multiplexing parts 8 and 9 and phase control parts 6b and 7b are applied with stress F by the deforming means as shown by an arrow 10, i.e., in a direction which is parallel to the top surface of a substrate 2 and perpendicular to the length direction of the control parts 6b and 7b, and then the phase control parts 6b and 7b are strained. The interference type light guide 5, therefore, has its branching ratio controlled by generating an optical path difference which is nearly as large as or less than wavelength between two waveguides 6 and 7 forming the control parts 6a and 7b. Consequently, remarkable branching ratio variation is obtained as compared with the case of a normal directional optical coupler. |
