Related Experiment Video
Updated: Jun 12, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Broadband flat-top gain characteristics based on three-component InGaAs/GaAs asymmetric quantum well
Optics Express
|June 11, 2026
Summary
This study presents an asymmetric quantum well (AQW) structure with a triple-component InGaAs/GaAs active region for enhanced spectral broadening. The novel design achieves a significantly wider and flatter modal gain spectrum, ideal for broadband light sources.
Area of Science:
- Semiconductor Physics
- Optoelectronics
- Materials Science
Background:
- Traditional quantum well structures face limitations in achieving broad and flat spectral gain.
- Developing advanced active regions is crucial for next-generation broadband light sources.
Purpose of the Study:
- To investigate the spectral performance improvements in an asymmetric quantum well (AQW) structure.
- To demonstrate a triple-component InGaAs/GaAs active region for flat, broadband gain.
- To analyze the potential of AQW for applications like superluminescent diodes and tunable lasers.
Main Methods:
- Utilized COMSOL-based simulations to model the energy band profile and quasi-Fermi level spacing.
- Designed a triple-component InGaAs/GaAs active region with varying indium compositions.
- Performed dual-facet electroluminescence (EL) measurements at room temperature to extract modal gain.
Main Results:
- The AQW structure exhibited a stepped energy band profile, extending quasi-Fermi level spacing by ~10%.
- Modal gain spectrum broadened significantly with increasing current density, reaching up to 105 nm FWHM (3.5x wider than traditional structures).
- Achieved a uniform gain profile over 900-1000 nm with a low gain ripple (~0.49).
Conclusions:
- The proposed asymmetric quantum well structure offers substantial advantages in spectral broadening and uniform output.
- Experimental and simulation results confirm the effectiveness of the triple-component InGaAs/GaAs active region.
- The AQW structure shows significant potential for developing advanced broadband light sources.
Related Concept Videos
01:23Small-Signal Analysis of MOSFET Amplifiers
In small-signal analysis, a MOSFET transistor amplifier acts as a linear amplifier when operating in its saturation region. The gate-to-source voltage (VGS) of the MOSFET is the sum of the DC biasing voltage and the small time-varying input signal. This combination sets up the operating point and modulates the drain current (ID) that flows from the drain to the source. When a small AC signal is superimposed on the DC bias voltage at the gate, the instantaneous drain current comprises three...
01:14BJT Amplifiers
Bipolar Junction Transistors (BJTs) are pivotal components in amplifier circuits, functioning as voltage-controlled current sources in their active region. This characteristic allows them to efficiently control the collector current through variations in the base-emitter voltage. Essentially, BJTs amplify power due to their ability to take a weak input signal and output a much stronger signal.
In BJT amplifier configurations, particularly in common-emitter setups, the transistor's role extends...
In BJT amplifier configurations, particularly in common-emitter setups, the transistor's role extends...
01:17MOSFET Amplifiers
The MOSFET, when operating in its active region, functions as a voltage-controlled current source. In this region, the gate-to-source voltage controls the drain current. This principle underlies the operation of the transconductance MOSFET amplifier. The output current is directed through a load resistor to convert this amplifier into a voltage amplifier. The output voltage is then obtained by subtracting the voltage drop across the load resistance from the supply voltage. This process results...
01:27Biasing of Metal-Semiconductor Junctions
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
01:16Biasing of P-N Junction
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
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...
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...
01:22Biasing of FET
Biasing a Junction Field Effect Transistor (JFET) is crucial for setting operational parameters and ensuring efficient functioning in electronic circuits. JFETs are characterized by using a single carrier type in N-channel or P-channel configurations, where the channel is surrounded by PN junctions. These junctions are central to the device's ability to control current flow.
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the gate...
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the gate...