CLA-2-90:S:N:N3:114 889867
Ms. Mary E. Gill
AT&T
Guilford Center 1 3A10
5420 Millstream Road
Greensboro, N.C. 27420
RE: The tariff classification of Garnet LPE Films for Optical
Isolators from Japan
Dear Ms. Gill:
In your letter dated August 26, 1993 you requested a tariff
classification ruling.
The Garnet LPE Film is used as part of an optical isolator. The optical
isolator is constructed using the Garnet LPE Film to enhance the function of
the laser diode used in fiber optic cable transmission or fiber optic
telecommunications. Optical isolators inhibit feedback light from the laser
diode by deflecting incoming light off to another angle. Optical isolators
containing Garnet LPE Film utilize the Faraday rotation of the garnet crystal
structure to rotate the beam of reflected light to prevent its reflection
back into the laser source, thereby preventing interruption and dilution of
the original laser beam.
The Garnet LPE Film consists of a thin ferromagnetic oxide crystal
containing terbium, holmium, gadolinium, or other rare earth elements. The
film is grown by a process known as liquid phase epitaxy (LPE), then ground
and polished to a specific size and thickness. The sizes range from 1 x 1 mm
to 15 x 15 mm, with thickness on the order of 0.5 mm. The Garnet LPE Film
is not doped for use in electronics.
The applicable subheading for the Garnet LPE Film will be 9001.90.9000,
Harmonized Tariff Schedule of the United States (HTS), which provides for
other optical elements, of any material, unmounted, other than such elements
of glass not optically worked. The rate of duty will be 8.4 percent ad
valorem.
This ruling is being issued under the provisions of Section 177 of the
Customs Regulations (19 C.F.R. 177).
A copy of this ruling letter should be attached to the entry documents
filed at the time this merchandise is imported. If the documents have been
filed without a copy, this ruling should be brought to the attention of the
Customs officer handling the transaction.
Sincerely,
Jean F. Maguire
Area Director
New York Seaport