running your os from the optical drive

Please explain what you're trying to do. If Windows is installed on the SSD, what are you trying to do with the optical drive? You can boot from an install disc or repair disc that's on the optical drive, but even a dual layer DVD wouldn't have enough capacity to hold a Windows 10 installed system. And even if it could, it would be so slow nobody would want it.
 


You may wish to change your phrasing - it's ambiguous.

If you have a caddy with a hard drive of any sort loaded into it as a replacement part for your optical drive, you can install Windows 10 on it per the usual methods and it will work. I know this because I just recently installed it on an SSD mounted in a optical drive caddy for my mother not long ago.