Broadband Transistor-Injected Dual Doping Quantum Cascade Laser

TL;DR

This paper introduces a novel transistor-injected dual doping quantum cascade laser (TI-D2QCL) that achieves a broad, flat gain spectrum across MIR and THz ranges by using dual doping and bias control, enabling wideband optical applications.

Contribution

The paper proposes a new device design, TI-D2QCL, with dual doping and bias control to produce a broad flat gain spectrum, advancing quantum cascade laser technology.

Findings

Achieves a gain spectrum from 9.41um to 12.01um with 24% bandwidth.

Demonstrates potential for wideband MIR and THz applications.

Model calculations confirm the effectiveness of the dual doping design.

Abstract

A novel design-friendly device called the transistor-injected dual doping quantum cascade laser (TI-D2QCL) with two different doping in each stack of a homogeneous superlattice is proposed. By adjusting the base-emitter bias Vbe of the bipolar transistor to supply electrons in the dual doping regions, charge quasi-neutrality can be achieved to generate different optical transitions in each cascading superlattice stack. These transitions are then stacked and amplified to contribute to a broad flat gain spectrum. Model calculations of a designed TI- D2QCL show that a broad flat gain spectrum ranging from 9.41um to 12.01um with a relative bandwidth of 0.24 can be obtained, indicating that the TI- D2QCL with dual doping pattern may open a new pathway to the appealing applications in both MIR and THz frequency ranges, from wideband optical generations to advanced frequency comb technologies.