Terahertz Metasurface Quantum-Cascade VECSELs: Theory and Performance

Xu, Luyao; Curwen, Christopher A.; Chen, Daguan; Reno, John L.; Itoh, T.; Williams, Benjamin S.

doi:10.1109/jstqe.2017.2693024

Cited by 27 publications

(26 citation statements)

References 48 publications

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“…To adjust the length of the cavity, we use piezoelectric stack actuators (Noliac NAC2121‐H28 which provides 43‐μm actuation range at room temperature). The output coupler mirror (described in [7 ]) exhibits reflectance >97% over the entire metasurface bandwidth. The high reflectance of the output coupler is used to maximise the potential bandwidth of lasing that can be observed by minimising threshold gain values.…”

Section: Resultsmentioning

confidence: 99%

Broadband metasurface design for terahertz quantum‐cascade VECSEL

Curwen

Reno

Williams

2020

Electronics Letters

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A broadband active metasurface is designed around quantum-cascade (QC) gain material for use in a broadband tunable QC vertical external-cavity surface-emitting laser (VECSEL). The metasurface is based on a unit cell containing two resonant waveguide elements that couple with the periodicity of the metasurface to produce a multiresonant reflection spectrum. Simulated reflectance spectra exhibit full-width half-maximum bandwidths up to 50% of the centre frequency. The tested QC-VECSEL demonstrates up to 15 mW of peak pulse power at 77 K and supports multimode lasing from 2.85 to 3.9 THz (>30% fractional bandwidth around 3.37 THz). The frequency coverage is limited by how short the cavity can be made, rather than the metasurface bandwidth. Consistent multimoding results from nonuniform distribution of spectral energy across the surface.

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Section: Resultsmentioning

confidence: 99%

Broadband metasurface design for terahertz quantum‐cascade VECSEL

Curwen

Reno

Williams

2020

Electronics Letters

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“…It was found that the power efficiency could be further improved (WPE ≈ 0.57% and PSE ≈ 450 mW A −1 ) when antenna loop structures were laterally integrated to the third-order DFB wire lasers to enlarge the effective emitting facet area. [101,140] [136] Alternatively, phase-locking of low-Q cavities is also an effective strategy to achieve high power efficiency while maintaining directional emission.…”

Section: Power Efficiencymentioning

confidence: 99%

Photonic Engineering Technology for the Development of Terahertz Quantum Cascade Lasers

Zeng

Qiang

Wang

2019

Advanced Optical Materials

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“…However, the mismatch between the mode in the deeply sub-wavelength-thick waveguide and that in the free space degrades severely the output power and the beam directionality. A number of unique photonic concepts have been developed to resolve this issue [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. For examples, THz quantum cascade wire lasers, exploiting a third-order distributed feedback (DFB) grating, exhibited low-divergence beam emission [16].…”

Section: Introductionmentioning

confidence: 99%

“…In addition, cavity configurations such as hybrid Bragg gratings, or graded photonic heterostructures, were exploited to excite a symmetric mode with high radiation efficiency, which resulted in pulsed output power in hundreds of milliwatt [22][23][24][25][26]. Very recently, quantum cascade metasurface-based vertical-external-cavity surface emitting lasers realized watt-level output power and a large range of frequency tuning [27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Modeling and improving the output power of terahertz master-oscillator power-amplifier quantum cascade lasers

Zhu¹,

Zhu²,

Chen³

et al. 2020

Opt. Express

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A model based on carrier rate equations is proposed to evaluate the gain saturation and predict the dependence of the output power of a terahertz master-oscillator power-amplifier quantum cascade laser (THz-MOPA-QCL) on the material and structure parameters. The model reveals the design rules of the preamplifier and the power extractor to maximize the output power and the wall-plug efficiency. The correction of the model is verified by its agreement with the experiment results. The optimized MOPA devices exhibit single-mode emission at ∼ 2.6 THz with a side mode suppression ratio of 23 dB, a pulsed output power of 153 mW, a wall-plug efficiency of 0.22%, and a low divergence angle of ∼6°×16°, all measured at an operation temperature of 77 K. The model developed here is helpful for the design of MOPA devices and semiconductor optical amplifiers, in which the active region is based on intersubband transitions.

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Terahertz Metasurface Quantum-Cascade VECSELs: Theory and Performance

Cited by 27 publications

References 48 publications

Broadband metasurface design for terahertz quantum‐cascade VECSEL

Broadband metasurface design for terahertz quantum‐cascade VECSEL

Photonic Engineering Technology for the Development of Terahertz Quantum Cascade Lasers

Modeling and improving the output power of terahertz master-oscillator power-amplifier quantum cascade lasers

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