Related papers: Frequency combs in optically-injected terahertz ri…
Optical frequency combs (FCs), that establish a rigid phase-coherent link between the microwave and optical domains of the electromagnetic spectrum, are emerging as a key high-precision tools for the development of quantum technology…
Quantum cascade lasers (QCLs) represent a fascinating accomplishment of quantum engineering and enable the direct generation of terahertz (THz) frequency radiation from an electrically-biased semiconductor heterostructure. Their large…
The ability to engineer quantum-cascade-lasers (QCLs) with ultrabroad gain spectra and with a full compensation of the group velocity dispersion, at Terahertz (THz) frequencies, is a fundamental need for devising monolithic and miniaturized…
This study investigates the interaction between frequency combs and optical feedback effects in Quantum Cascade Lasers (QCLs). The theoretical analysis reveals new phenomena arising from the interplay between comb generation and feedback.…
In this work, a design for a mid-infrared quantum cascade laser (QCL) frequency comb source that enhances the high frequency response and the comb characteristics of the device is presented . A state-of-the-art active region (AR), grown on…
Ring quantum cascade lasers (QCLs) proved to be a versatile tool for generating tunable and stable frequency combs in the mid infrared range in the form of quantum walk combs. By homogeneously integrating a racetrack QCL with a passive…
Quantum cascade lasers are compact sources capable of generating frequency combs. Yet key characteristics - such as optical bandwidth and power-per-mode distribution - have to be improved for better addressing spectroscopy applications.…
We present quantum cascade laser (QCL) frequency comb devices with engineered waveguides for managing the dispersion. The QCL waveguide consists of multiple sections with different waveguide widths. The narrow and wide sections of the…
Terahertz quantum cascade laser sources based on intra-cavity difference frequency generation from mid-IR devices are an important asset for applications in rotational molecular spectroscopy and sensing, beingthe only electrically pumped…
We report a homogeneous quantum cascade laser (QCL) emitting at Terahertz (THz) frequencies, with a total spectral emission of about 0.6 THz centered around 3.3 THz, a current density dynamic range of Jdr=1.53, and a continuous wave output…
We present homogeneous quantum cascade lasers (QCLs) emitting around 3 THz which display bandwidths up to 950 GHz with a single stable beatnote. Devices are spontaneously operating in a harmonic comb state, and when in a dense mode regime…
We present an extended study concerning the dynamics of dense and harmonic coherent regimes in quantum cascade lasers (QCLs) in a Fabry--Perot (FP) configuration emitting in the terahertz (THz) spectral region. Firstly, we study the device…
The mid-infrared (mid-IR) regime (typically the wavelength regime of $\lambda \sim 2.5-20 \ \mathrm{\mu m}$) is an important spectral range for spectroscopy as many molecules have their fundamental rotational-vibrational absorption in this…
Quantum cascade lasers (QCLs) facilitate compact optical frequency comb sources that operate in the mid-infrared and terahertz spectral regions, where many molecules have their fundamental absorption lines. Enhancing the optical bandwidth…
Optical frequency combs establish a rigid phase-coherent link between microwave and optical domains and are emerging as high-precision tools in an increasing number of applications. Frequency combs with large intermodal spacing are employed…
It was recently demonstrated that broadband quantum cascade lasers can operate as frequency combs. As such, they operate under direct electrical pumping at both mid-infrared and THz frequencies, making them very attractive for dual-comb…
Quantum cascade lasers are proving to be instrumental in the development of compact frequency comb sources at mid-infrared and terahertz frequencies. Here we demonstrate a heterogeneous terahertz quantum cascade laser with two active…
We present a method for engineering harmonic frequency combs (HFCs) in the terahertz spectral region. This approach involves interfacing a quantum cascade laser (QCL) with an external reflector featuring frequency-dependent reflectivity. A…
We demonstrate the use of a low power near-infrared laser illuminating the front facet of a quantum cascade laser (QCL) as an optical actuator for the coherent control of a mid-infrared frequency comb. We show that by appropriate current…
We report on a heterogeneous active region design for terahertz quantum cascade laser based frequency combs. Dynamic range, spectral bandwidth as well as output power have been significantly improved with respect to previous designs. When…