Hi Neelam,

When you say model a fiber coupler, what do want to model? Do you just want to model the output of two fibers at the end? By that I mean not the propagation along the fibers and the exchange of energy due to fibers being in close proximity to each other. In OpticStudio, it is not possible to model the propagtion along a fiber unless the fiber is multimode. If a fiber can support many modes, then it can be modelled as a light pipe (this would be in NSC mode), but this still would not model the coupler just the output. In summary, it won't be possible to model the coupler, but we could simualte the two fiber outputs from the coupler. Are you trying to model a coupler for single or multimode fibers?

https://my.zemax.com/en-US/forum/threads/11393ae4-1e2e-e911-a96a-000d3a37870e

Let me know what you think,

Ali