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Resonant Amplification Enhanced Terahertz Quantum Cascade Detection
(2021)2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)The photon-driven nature of the transport in terahertz quantum cascade laser can be exploited to detect light. Fast tunable detectors are demonstrated with responsivities higher than 17 V/W. Preliminary measurements shows that, thanks to the sub-ps intersubband lifetime, electrical bandwidths larger than 5 GHz can be obtained.Conference Paper -
Distributed Feedback Quantum Cascade Lasers at 3.2 µm
(2014)Optics ExpressIn this work, we present GaInAs/AlAs/AlInAs quantum cascade lasers emitting from 3.2 to 3.4 μm. Single-mode emission is obtained using buried distributed-feedback gratings fabricated using standard deep-UV contact lithography. This technique can easily be transferred to industrial production. Devices with single-mode emission down to 3.19 μm were achieved with peak power of up to 250 mW at −20 °C. A tuning range of 11 cm−1 was obtained ...Conference Paper -
THz Intersubband Emitter based on Silicon
(2021)2021 27th International Semiconductor Laser Conference (ISLC)We present THz quantum cascade emitters realized on a Si substrate. The emission centered at 3.4 and 4.9 THz originates from L-valley transitions in strain-compensated n-type Ge/SiGe heterostructures. This is an important step towards the realization of Si-based THz quantum cascade lasers.Other Conference Item -
Self-Starting Harmonic Combs in THz Quantum Cascade Lasers
(2021)2021 Conference on Lasers and Electro-Optics (CLEO)We report on high temperature, self-starting THz Quantum Cascade Laser harmonic frequency combs. Their coherence is assessed by electrical beatnote measurements and a self-mixing technique and their beatnote can be injection-locked to a RF source.Conference Paper -
All-Mid-Infrared Stabilized Quantum Cascade Laser Frequency Comb with 30-kHz Frequency Stability at 7.7 mu m
(2021)2021 Conference on Lasers and Electro-Optics (CLEO)High-resolution spectroscopy in the mid-infrared requires stable frequency references. A frequency comb emitted by a quantum cascade laser is locked to a molecular transition, demonstrating 30-kHz frequency stability up to 5000-s integration time.Conference Paper -
Femtosecond pulses from a mid-infrared quantum cascade laser
(2021)2021 27th International Semiconductor Laser Conference (ISLC)We report on the generation of near-transform-limited femtosecond pulses from a mid-infrared quantum cascade laser by external pulse compression. The temporal nature of these pulses is assessed by means of a novel optical sampling method, coherent beatnote interferometry and interferometric autocorrelation.Other Conference Item -
Coherently-Averaged Dual-Comb Spectrometer at 7.7 µm with Master and Follower Quantum Cascade Lasers
(2021)2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)Mid-infrared (MIR) quantum cascade laser (QCL) frequency combs are an appealing technology for dual-comb spectroscopy as they cover strong absorption bands of many relevant molecules in the MIR region and enable measurements with sub-microsecond time-resolution permitting novel insights into dynamical processes [1] . The comb properties can be directly controlled through the QCL driving current, the chip temperature or by electrical ...Conference Paper -
Gapless high-resolution QCL dual-comb spectroscopy with real-time data processing for dynamic gas-phase measurements
(2021)2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)Quantum cascade laser frequency combs (QCL-FCs) are mid-infrared sources capable of producing several hundred comb lines spanning tens of cm -1 . In the dual comb configuration, two nearly identical frequency combs with slightly different comb spacing are used as an interrogating and local oscillator comb to probe the absorption or refractive index of a sample [1] . The repetition frequency of the interrogating comb determines the point ...Conference Paper -
Shifted Wave Interference Fourier Transform Spectroscopy of THz Quantum Cascade Laser Frequency Combs operating above 70 K
(2021)2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)Quantum Cascade Lasers (QCLs) are compact and powerful sources for frequency comb generation in the mid-IR and THz regime [1] , [2] . The generation and locking of the frequency comb modes is based on four-wave mixing inside the active region and leads to FM modulated emission. Experimentally, the intensity profile in time resp. the phase relation between comb modes is measured by Shifted Wave Interference Fourier Transform (SWIFT) ...Conference Paper -
Influence of resonator design on ultrastrong coupling between a two-dimensional electron gas and a THz metamaterial
(2013)Proceedings of SPIE ~ Ultrafast Phenomena and Nanophotonics XVIITHz metamaterials have been shown to be a promising candidate for CQED experiments, i.e. Ultrastrong coupling has been demonstrated.1 Modes of split ring resonators (SRRs) have been coupled via the AC-electric field to inter landau level transitions in two dimensional electron gases (2DEGs). SRR typically exhibit two distinct electromagnetic modes.2 One mode consists of an electric field confined in the slit of the resonator, while current ...Conference Paper