| Abstract: | This paper reports that a two-dimensional single-defect photonic
crystal waveguide in the \textit{$\Ga$-K} direction with triangular
lattice on a silicon-on-insulator substrate is fabricated by the
combination of electron beam lithography and inductively coupled
plasma etching. A ministop band (MSB) is observed by the measurement
of transmission characteristics. It results from the coupling
between the two modes with the same symmetry, which is analysed from
the stimulated band diagram by the effective index and the
two-dimensional plane wave expansion methods. The parameter working
on the MSB is the ratio of the radius of air holes to the lattice
constant, $r/a$. It is obtained that the critical $r/a$ value
determining the occurrence or disappearance of MSB is 0.36. When
$r/a $ is larger than or equal to 0.36, the MSB occurs. However,
when $r/a $ is smaller than 0.36, the MSB disappears. |
