Generally speaking, unluckily for you, you are not the owner of any innovative idea regarding your work as employee in a company.
Find here an useful reference on patents from employees in France
As a matter of facts, very few positions in French industry are of the type you could prefer in this case... in all other cases the employer is, or is entitled to become, the only owner of your inventions related to his business.
In theory, the maximum you can do, if you are so sure of your idea, is to leave your work, make your research and, after some time, come back to your company and to competitors to negotiate the experimental application.
But it can be considered at the limit of ethics boundaries, very probably out of them for many courts.
But please remember this before doing anything: the most of the “revolutionary ideas” synthesized by a newbie in a business... result to be not applicable for same detail not known or not understood.
This is cruel statistics, because you newbie know only some aspects of the problem, and underestimate difficulties.
Anyway, ask the same question in general to your boss and try to understand more about your specific contractual duty.