【摘要】 将渐变波导模式方程（WKB积分方程）化为分段积分,以波导某一模式在不同波长下的转折点为分段点,当波长相差很小时,相应的转折点相差也很小,可在各个分段积分中作折线近似,从而从理论上推出确定波导轮廓数据的递推式.以所得轮廓必须满足光滑条件为判据,最后定出波导的轮廓.该方法尤其适用于单模渐变波导,而且无需事先假设待定轮廓的函数形式.本文对双曲止割和抛物线轮廓的理想波导进行了计算机模拟,结果证明该方法的精度达到10^-3甚至于更高.而且理论上具有分割愈密,精度愈高的优点.更多还原

【Abstract】 The mode equation of graded wavequide (WKB integral equation) was divided into many segmental integrals and their terminal values points were set at the turning points of the same mode at different wavelengths. When the differences of the wavelengthe were small enough, the deviations for the corresponding turning points are also small enough, the broken lines approximations oould be made in these segmental integrals. Then, we theoretically obtained a recurrence formula for calculating the refractive index profile. The profile can be finally determined by picking up the smoothest one. This method is especially applicable for monomode waveguide and it is unnecessary to presuppose the function type of the profile.Computer simulations are made for model waveguides with the profiles of hyperbolic secant and parabolic types in this paper and the calculation had proved that the new method is with the precision of 10-3 or even higher. The more segments were divided, the higher precision could be reached.更多还原