Appeal No. 1997-3303 Page 9
Application No. 08/171,126
region with a part of the perturbation portion. Okai goes on to state (col. 2, lines 40-44) that the
plurality of separate electrodes formed on the feedback region so as to correspond to different areas of
the perturbation portion, can be used as the above-mentioned structure. This is best shown in figures
7A and 7B. Figure 7A shows (col. 6, lines 22-32) light distribution as hatched region (715) in
response to a uniformly applied electric field. Okai specifically states (col. 6, lines 32-40) that:
When the voltage is applied to one of the separate electrodes 707 or the current
supplied to the electrode is varied to change the refractive index of that part of
the optical guide layer 706 which corresponds to the above electrode, the light
intensity distribution in the feedback region is varied as shown in FIG. 7B, and
thus the degree of coupling of light traveling in the feedback region with that
part of that perturbation portion 711 which corresponds to the electrode, is varied.
Appellants argue (rbrief, page 11) that at most, Okai can be viewed as disclosing the formation of a
sectional grating which is a physical grating, and that appellants do not physically form a grating but
instead disclose the formation of an electro-optic grating. Appellants’ statement that they do not
“physically form a grating” is inconsistent with the specification which discloses (page 7, lines 18-20)
that “a conductive material is deposited upon the cladding region 16 in the form of a grating 17 as
shown in Fig. 8 by photolithographic techniques.” We believe that appellants meant to state that the
instant invention replaces the corregated gratings found in Sakata and Okai with an electro-optic grating
that eliminates the need for a corregated grating by applying a difference of potential across the cladding
or waveguide that results in the preparation of a grating of controlled refractive index, with the control
being obtained by regulation of the voltage bias (specification, page 9). However, in view of Okai’s
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