Oops,this file from optisystem 13.you cant open it.Have you tried trial version? Which is free of cost?you can download it and use fir 30 days.If you have that download already then you can use the file i have attached.However i have just modified the sample from optisystem v11 file in v13 using fso and it works fine and covers almost 2-3 Km .Also work for 100Gbps and more with error free communication.