noun
half mirror; one-way mirror; 50% beam splitter
A mirror that reflects about half the light and transmits the rest. In everyday contexts, it often refers to a one-way mirror used for observation or privacy. In optics, it can specifically mean a 50% beam splitter.
取調室にはハーフミラーが設置されている。
A one-way mirror is installed in the interrogation room.
光学実験でハーフミラーを使
In the optics experiment, we split the light using a half mirror.