Only if you have not applied for a patent. If you have applied for a patent, assuming this is a real discovery and it is a valid application, you will be widely replicated after the application is made public. That happens before the patent is granted (if ever). So you might as well help people replicate now. There are benefits to having people replicate. They confirm your claims. There is a problem, too. They may start intensive research and find ways to improve the device before you do. But you will not lose the original intellectual property.
Sure but it does not always work that way, and most of the time, if it is possible, you go for a combination of patent and trade secret. You have a patent with the bare minimum in it, and you keep the rest under wrap as a trade secret. This is exactly what Brillouin is doing, as they have obtained patents in all major jurisdictions outside of the US but the content of those patents is not sufficient to allow replication.