| 摘要 |
PURPOSE: To provide a laser, having a wide tuning range by providing an optical Y-joint at each one end of first, second, and third of an optical branch wave body with each end of first, second, and third path length which has a path length longer than the second, while the other ends of the second and third are terminated to a common flat surface. CONSTITUTION: An optical wave director of an array constitutes a first branch 26 combined to both first and third branches 30 and 32 through a Y-joint element 28. These two branches 30 and 32 of an asymmetrical Y-branch are terminated vertical with respect to the propagation of the two wave bodies, to points 46 and 48 in common with the flat surface. The two branches 30 and 32 of the asymmetrical Y-branch have different lengths required for the normal operation of a Mach-Zehnder interferometer. Three control electrodes 34, and 44 are provided on the corresponding branches 26, 30, and 32, each having a gain. By extending an asymmetrical Y-branch optical element at a right-angle plane, the Mach-Zehnder interferometer is incorporated in a frequency-selection mechanism lying on a lower side. |
