An optical identification element (also known herein as a microbead) that
is made from pieces of an optical fiber or substrate that includes an
inner core or region being surrounded by an outer cladding region. The
optical fiber or substrate has an identification code imparted therein
containing coded information. The identification code may be in the form
of a Bragg grating inscribed or written in either the inner core or outer
cladding. The optical identification element may be microscopic in size
having a length in a range of 1-1,000 microns or smaller; or for larger
applications may have a length of 1.0-1,000 millimeters or more. The
outer diameter may be as small as less than 1,000 microns, as well as in
a range of 1.0 to 1,000 millimeters for larger applications.