利用数值模拟的方法研究了倾斜入射的傍轴光束在有限宽非线性平板波导内的传输规律.研究发现,当不同波长相同束宽的光束各以临界功率倾斜入射波导时,如果倾斜角、入射点都一样,它们将沿大致相同的周期性的Z字形路径传输;如果光束功率进一步增大,相邻反射点之间的间距随传输距离有逐渐变大的趋势,Z字形路径不再有严格的周期性;当功率相当大时,光束将沿波导z方向传输,不再在波导的两个边界之间来回反射.利用倾斜入射光束在波导内的传输路径随功率而变的特点,设计了一个功率开关和一个光时分解复用器.
The propagation of paraxial light beams injected at an inclined angle in a planar waveguide with finite width is studied by numerical method. The soliton beams with different wavelength and same width, if their incident point and incident slanting angle are the same, will propagate along the same periodic Z-type route in the planar waveguide. With the power of the beam increasing, the distance between two adjacent reflecting points will become longer and longer with the propagation distance and the Z-type route will lose its periodicity. When the power of a beam become fairly strong, the beam will propagate along z direction of the waveguide, and will no longer be reflected back and forth between the two boundaries of the planar waveguide. Using the characteristic that a beam injected at an inclined angle in the waveguide will propagate along different route with different power, a power switch and an optical time division demultiplexer are designed.