平板波导TM模的群速度研究

Studies of the group velocity of TM modes in planar waveguide

借助Mathematic数学分析软件推导复杂的公式,以能量密度除能流密度的方法分析了平板波导中TM模式的群速度,所得到的结果与用传播常数对角频率取导数推导得出的群速度形式完全相同,而且TM模的群速形式与TE模的群速形式也完全相同,佐证了能量是以群速度传播的这一结论.

With the aid of Mathematic software, we calculate the group velocity of TM mode in planar waveguide by dividing energy flux density by energy density, and get the same result by performing the derivative of the propagation constant with respect to the angular frequency of the guided mode, which demonstrates that energy propagates with the group velocity.