Title :
Electroabsorption and electrooptic effect in SiGe-Si quantum wells: realization of low-voltage optical modulators
Author :
Qasaimeh, Omar ; Singh, Jasprit ; Bhattacharya, Pallab
Author_Institution :
Solid State Electron. Lab., Michigan Univ., Ann Arbor, MI, USA
fDate :
9/1/1997 12:00:00 AM
Abstract :
We have calculated the behavior of the band-to-band absorption coefficient in square, coupled, and graded bandgap Si0.6Ge 0.4-Si quantum wells as a function of the transverse electric field. It is seen that due to the weak confinement of the electrons (ΔEc⩽20 meV) the absorption of photons with energy equal to the interband transition energy can be reduced at very small values of the transverse electric field. This phenomenon lends itself to the design of efficient amplitude modulators. In addition, the resulting change in the refractive index is also large and the corresponding linear electrooptic coefficient is calculated to be as large as 1.9×10-10 m/V in square wells. This effect could prove to be the basis for the realization of efficient Si-based electrooptic modulators. Device designs are discussed
Keywords :
Ge-Si alloys; Stark effect; absorption coefficients; electroabsorption; elemental semiconductors; refractive index; semiconductor quantum wells; silicon; Si-based electrooptic modulator design; SiGe-Si; SiGe-Si quantum wells; band-to-band absorption coefficient; corresponding linear electrooptic coefficient; efficient amplitude modulators; electroabsorption; electrooptic effect; graded bandgap Si0.6Ge0.4-Si quantum wells; interband transition energy; low-voltage optical modulators; refractive index; transverse electric field; Absorption; Electrons; Electrooptic effects; Electrooptic modulators; Optical modulation; Optical refraction; Optical variables control; Photonic band gap; Refractive index; Stark effect;
Journal_Title :
Quantum Electronics, IEEE Journal of
