Title :
All-optical switch utilizing intersubband transition in GaN quantum wells
Author :
Iizuka, Norio ; Kaneko, Kei ; Suzuki, Nobuo
Author_Institution :
Corporate Res. & Dev. Center, Toshiba Corp., Kawasaki
Abstract :
Intersubband transition (ISBT) in GaN quantum wells (QWs) was investigated from the viewpoint of application to ultrafast all-optical switches. The effect of crystalline quality on the absorption saturation characteristics was examined and reduction of edge dislocations was found to be a crucial factor in decreasing operation energy. Then, the switching performance was investigated for devices with improved crystalline quality. Modulation of signal pulses with a pulse interval of less than 1 ps was confirmed. Another device displayed gate-switch operation with an extinction ratio of greater than 10 dB. Comparison of the absorption recovery process in both devices suggested that the process is strongly affected by the QW structure
Keywords :
III-V semiconductors; edge dislocations; gallium compounds; high-speed optical techniques; optical saturable absorption; optical switches; semiconductor quantum wells; wide band gap semiconductors; GaN; GaN quantum wells; absorption recovery; absorption saturation; all-optical switch; displayed gate-switch; edge dislocation; extinction ratio; intersubband transition; signal pulse modulation; Absorption; Communication switching; Crystallization; Extinction ratio; Gallium nitride; Optical fiber communication; Optical polarization; Optical switches; Optical waveguides; Pulse modulation; Gallium nitride; intersubband transition; optical switches; quantum wells;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2006.878189
