Role of photonic bandgaps in polarization-independent grating waveguide structures.
Polarization independence in a one-dimensional resonant grating waveguide structure involves the simultaneous excitation of two guided modes propagating in different directions. Possible simultaneous excitations occur when the two excited guided modes have either the same polarization, i.e., TE-TE (transverse electric) or TM-TM (transverse magnetic), or different polarizations, i.e., TE-TM. Simultaneous excitations may result in bandgaps and singularities. We confirm and show that in order to achieve polarization independence, it is necessary to find the conditions that minimize the effects of such bandgaps and singularities and experimentally demonstrate tunable polarization independence for simultaneously excited TE-TM-guided modes.
Grinvald
Eran
E
Weizmann Institute of Science, Rehovot 76100, Israel. eran.grinvald@weizmann.ac.il
Katchalski
Tsvi
T
Soria
Silvia
S
Levit
Shimon
S
Friesem
Asher A
AA