Title :
Design and analysis of low-chirp electroabsorption modulators using bandstructure engineering
Author :
Yamanaka, Takayuki ; Yokoyama, Kiyoyuki
Author_Institution :
NTT Opto-Electron. Labs., Kanagawa, Japan
Abstract :
The design principle for completely negative-chirp operation of an electroabsorption (EA) modulator in the 1.55 μm window is studied theoretically in InGaAsP strained quantum well (QW) structures for strain ranging from compressive to tensile. The small-signal chirp parameter for TE polarization is evaluated from calculated EA spectra based on k·p theory and their Kramers-Kronig transformed refractive index changes. It is found that both compressive and tensile strain in the well layer reduce the chirp parameter The compressive-strained QW lowers the chirp parameter to nearly zero or negative values, the amount of the reduction being proportional to strain amount. In a tensile-strained QW, almost continuously negative values irrespective of applied electric fields occur at an optimized amount of strain
Keywords :
III-V semiconductors; Kramers-Kronig relations; chirp modulation; electro-optical modulation; electroabsorption; gallium arsenide; indium compounds; k.p calculations; refractive index; semiconductor quantum wells; 1.55 micron; InGaAsP; InGaAsP strained quantum well; Kramers-Kronig transformation; TE polarization; band structure engineering; chirp parameter; design; electroabsorption modulator; k·p theory; refractive index; Absorption; Chirp modulation; Design engineering; Optical pulse compression; Optical pulse generation; Optical transmitters; Pulse modulation; Refractive index; Tensile strain; Wavelength division multiplexing;
Conference_Titel :
Physics and Modeling of Devices Based on Low-Dimensional Structures, 1998. Proceedings., Second International Workshop on
Conference_Location :
Aizu-Wakamatsu
Print_ISBN :
0-8186-8682-0
DOI :
10.1109/LDS.1998.714531