Hello Sandeep,
You will need to be more specific regarding what you are having issues with. If it is using the software in general I would recommend you check out the <a href=”https://optiwave.com/category/optifdtd-manuals/optifdtd-background-and-tutorials/a3-lesson-1-getting-started/”>Getting Started</a> link on our website where it walks you through the creation of a ring resonator.
Also you should check out our webinar videos located <a href=”https://optiwave.com/category/resources/webinars/”>here</a>. There are many introductory videos on OptiFDTD that will help you get things rolling.
Scott