I just found it on the wiki.
Here it is copy and paste of the wiki
Raiden was named after the Mitsubishi J2M Raiden, an Imperial Japanese WWII fighter aircraft (which was also used in a fictional fighter craft named the "Raiden mk-II"). The Allied codename for the plane was "Jack" during WWII. Going by what JD stated when goading Raiden into killing Solidus, it can be assumed that they gave Raiden that codename in order to convince him that he is nothing more than a weapon, a tool to be discarded once its usefulness has been outlived