The cutoff condition of HE, EH, TE, and TM modes is formulated in an integral equation by using a Sturm-Liouville-type boundary problem. A formula for calculating the cutoff frequencies of the TM01 and HE21 modes is derived in addition to the TE01 cutoff by calculating the eigenvalue of this integral equation. The cutoff frequencies of the TM01 and HE21 modes are calculated and compared with those of the TE01 mode for various index profiles. As a result, the cutoff frequency of the TM01 mode is dominant for the single-mode limit over frequencies of the TE01, TM01, and HE21 modes for the α-power law index profile. However, in the case of an index profile including a center dip, the cutoff frequency of the TE01 mode dominates the single-mode condition.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.