Microwave modulation of terahertz quantum cascade lasers: a transmission-line approach

Maineult, W.; Ding, Lu; Gellie, P.; Filloux, Pascal; Sirtori, Carlo; Barbieri, Stefano; Akalin, T.; Lampin, J.-F.; Sagnes, I.; Beere, Harvey E.; Ritchie, D. A.

doi:10.1063/1.3284518

Cited by 56 publications

(56 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To date, there has been limited experimental investigation of the modulation bandwidth of THz QCLs, although device-dependent values of the order of a few GHz have been reported. 12,19,20 The simulated increase in modulation bandwidth as the drive current approaches the peak of the L-I curve is in qualitative agreement with experimental measurements of mid-IR QCLs, 7 and this could form the basis of future measurements of THz devices. Time-resolved solutions for the photon and carrier populations in response to high speed square-wave modulation are shown in Fig.…”

supporting

confidence: 66%

Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

Agnew

Grier

Taimre

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

Terahertz-frequency quantum cascade lasers (THz QCLs) based on bound-to-continuum active regions are difficult to model owing to their large number of quantum states. We present a computationally efficient reduced rate equation (RE) model that reproduces the experimentally observed variation of THz power with respect to drive current and heat-sink temperature. We also present dynamic (time-domain) simulations under a range of drive currents and predict an increase in modulation bandwidth as the current approaches the peak of the light–current curve, as observed experimentally in mid-infrared QCLs. We account for temperature and bias dependence of the carrier lifetimes, gain, and injection efficiency, calculated from a full rate equation model. The temperature dependence of the simulated threshold current, emitted power, and cut-off current are thus all reproduced accurately with only one fitting parameter, the interface roughness, in the full REs. We propose that the model could therefore be used for rapid dynamical simulation of QCL designs.

show abstract

supporting

confidence: 66%

Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

Agnew

Grier

Taimre

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…In this respect we note that, at difference from the experiment, a RF applied to the whole cavity does not yield the same effect and it leaves the system in the chaotic state with little effect on the BNS. A possible explanation of this apparent discrepancy may lie in microwaves attenuation, estimated of few dB/mm [44], that removes spatial uniformity in the experiments. …”

Section: Effect Of Rf Modulationmentioning

confidence: 98%

Dynamics of a broad-band quantum cascade laser: from chaos to coherent dynamics and mode-locking

Columbo¹,

Barbieri²,

Sirtori³

et al. 2018

Opt. Express

Self Cite

View full text Add to dashboard Cite

Abstract:The dynamics of a multimode Quantum Cascade Laser, is studied in a model based on effective semiconductor Maxwell-Bloch equations, encompassing key features for the radiationmedium interaction such as an asymmetric, frequency dependent, gain and refractive index as well as the phase-amplitude coupling provided by the Henry factor. By considering the role of the free spectral range and Henry factor, we develop criteria suitable to identify the conditions which allow to destabilize, close to threshold, the traveling wave emitted by the laser and lead to chaotic or regular multimode dynamics. In the latter case our simulations show that the field oscillations are associated to self-confined structures which travel along the laser cavity, bridging mode-locking and solitary wave propagation. In addition, we show how a RF modulation of the bias current leads to active mode-locking yielding high-contrast, picosecond pulses. Our results compare well with recent experiments on broad-band THz-QCLs and may help understanding the conditions for the generation of ultrashort pulses and comb operation in Mid-IR and THz spectral regions.

show abstract

“…In our previous work on single plasmon waveguides, pulses were generated over a wide range of round-trip modulations (12.5 13.3 GHz). The difference here comes from the metal-metal waveguide which brings an extra dispersion in the refractive index of the microwave modulation and permits a THz-GHz phase matching [19], where the effective microwave index is equal to the THz group refractive index i.e. nG(THz)=neff(GHz).…”

Section: Active Modelockingmentioning

confidence: 99%

Generating ultrafast pulses of light from quantum cascade lasers

Wang¹,

Maussang²,

Moumdji³

et al. 2015

Optica

View full text Add to dashboard Cite

The generation of ultrashort pulses from quantum cascade lasers (QCLs) has proved to be challenging. It has been suggested that the ultrafast electron dynamics of these devices is the limiting factor for modelocking and hence pulse formation. Even so, clear modelocking of terahertz (THz) QCLs has been recently demonstrated but the exact mechanism for pulse generation is not fully understood. Here we demonstrate that the dominant factor necessary for active pulse generation is in fact the synchronization between the propagating electronic modulation and the generated THz pulse in the QCL. By using phase resolved detection of the electric field in QCLs embedded in metal-metal waveguides, we demonstrate that active modelocking requires the phase velocity of the microwave round trip modulation to equal the group velocity of the THz pulse. This allows the THz pulse to propagate in phase with the microwave modulation along the gain medium, permitting short pulse generation. Modelocking was performed on QCLs employing phonon depopulation active regions, permitting coherent detection of large gain bandwidths (500 GHz), and the generation of 11 ps pulses centered around 2.6 THz when the above 'phase-matching' condition is satisfied. This work brings an enhanced understanding of QCL modelocking and will permit new concepts to be explored to generate shorter and more intense pulses from mid-infrared, as well as THz, QCLs.

show abstract

Microwave modulation of terahertz quantum cascade lasers: a transmission-line approach

Cited by 56 publications

References 16 publications

Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

Dynamics of a broad-band quantum cascade laser: from chaos to coherent dynamics and mode-locking

Generating ultrafast pulses of light from quantum cascade lasers

Contact Info

Product

Resources

About