The thermal barrier (12) is made of borosilicate glass. It is used with an optical bench (10), in particular an optical bench (10) of an optical module assembly (20). It provides thermal insulation during the alignment of an optical fiber (26). A method of thermally insulating an optical bench (10) from a substrate (32) using the thermal barrier (12) is also disclosed. The thermal barrier (12) reduces the heat transfer to neighboring components during the fiber alignment.
