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Electro-optical effects in strain-compensated InGaAs/InAlAs coupled quantum wells with modified potential.
Zhixin Xu1, Changrong Wang, Wei Qi
1College of Science, Zhejiang University of Science and Technology, Hangzhou 310023, China. xuzhixin19721005@yahoo.com.cn
Optics Letters
|March 3, 2010
Summary
Strain-compensated InGaAs/InAlAs coupled quantum wells exhibit significant electro-optic modulation. These modified potential devices show a large refractive index change, ideal for electro-optical switches.
Area of Science:
- Materials Science
- Optoelectronics
- Semiconductor Physics
Background:
- Coupled quantum wells are crucial for optoelectronic devices.
- Strain compensation in InGaAs/InAlAs systems enhances material properties.
- Modified potentials can tune quantum well characteristics.
Purpose of the Study:
- To design and experimentally investigate strain-compensated InGaAs/InAlAs coupled quantum wells with modified potentials.
- To evaluate the electro-optic modulation performance of these quantum wells.
- To assess their potential for application in reflection-type electro-optical switches.
Main Methods:
- Design and fabrication of strain-compensated InGaAs/InAlAs coupled quantum wells with modified potential.
- Photocurrent spectroscopy at room temperature.
- Optical characterization at 1.55 µm to determine absorption loss and refractive index change.
Main Results:
- Calculated blueshift of the lowest excitonic peak at 50 kV/cm is 40.6 meV.
- Observed upward shift of the apparent peak position exceeding 35 meV under -4 V reverse bias.
- Achieved low absorption loss (9.8 cm⁻¹) and a large negative refractive index change (-0.0095) at 1.55 µm.
Conclusions:
- The designed strain-compensated InGaAs/InAlAs coupled quantum wells with modified potential demonstrate significant electro-optic effects.
- The observed large negative refractive index change and low absorption loss indicate suitability for optical modulation.
- These quantum wells show great potential for application in reflection-type electro-optical switches.
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