Related Experiment Video
Updated: May 3, 2026

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Coupled tandem cavities based electro-absorption modulator with asymmetric tandem quantum well for high modulation
Abstract:
We propose and demonstrate a new electro-absorption modulator (EAM) based on coupled tandem cavities (CTC) having asymmetric tandem quantum well (ATQW) structure with separated electrode configuration to achieve large transmittance change over a broad spectral range at low driving voltage for high definition (HD) 3D imaging applications. Our theoretical calculations show that CTC with ATQW structure can provide large transmittance change over a wide spectral range at low driving voltage. By introducing separated electrode configuration, the fabricated EAM having CTC with ATQW structure shows a large transmittance change over 50%, almost three times larger spectral bandwidth compared to that of EAM having single cavity with a single thickness quantum well without significantly increasing the applied voltage. In addition, the CTC with ATQW structure also shows high speed modulation up to 28 MHz for the device having a large area of 2 mm x 0.5 mm. This high transmittance change, large spectral bandwidth and low voltage operation over a large device area for the EAM having CTC with ATQW demonstrates their huge potential as an optical image modulator for HD 3D imaging applications.
Related Concept Videos
MOSFET: Enhancement Mode
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
MOSFET Amplifiers
Biasing of P-N Junction
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
Biasing of Metal-Semiconductor Junctions
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
Bipolar Junction Transistor
MOSFET: Depletion Mode
The primary characteristic of depletion-mode MOSFETs is their ability to conduct current between the drain and source terminals without gate bias. This inherent conductivity...

