I want to know this U-shape photoelectric sensor's manufacturer and item number.?

READ ITS LABEL ON ITS SIDE, THEN SEARCH IT WITH GOOLE.
OR ITS PARTS NUMBER CAN BE FOUND FROM THE SYSTEM SERVICE MANUAL FOR THAT SENSOR THAT YOU TOOK IT OUT.

What is on the label on the side? That appears to have that info.

There is a logo there. And a model number on the top right. Just read them.

edit: "Update: Note: There is no label on it."
then what is that a photo of? I can clearly see two labels. Perhaps you should have your eyes checked.