Photonics Research, Volume. 6, Issue 2, 117(2018)
Terahertz emission from localized modes in one-dimensional disordered systems [Invited]
Fig. 1. Diagram of the THz QCL structure with a 1D disordered grating. Insets: top view of the device (top left), and scanning electron microscope (SEM) image of the fabricated QCL with disordered grating (bottom right); here, the aperture width is 3.5 μm and the disorder degree is 0.2.
Fig. 2. (a) Ensemble-averaged transmission spectrum over 100 different configurations of the 1D disordered gratings for each degree of disorder. In the simulation, the 3D disordered waveguide structure was simplified to a 1D grating using an estimated refractive index contrast and without considering waveguide or material loss. (b) Ensemble-averaged gain threshold, calculated from 20 different configurations for each degree of disorder and taking the mean gain threshold at each frequency bin. The simulation was simplified to a 2D calculation of the structural cross sections where the
Fig. 3. (a) LIV curves and (b) emission spectrum at 4.26 A for the fabricated 1D periodic QCL. (c) LIV curves and (d) emission spectra for the fabricated 1D disordered QCL with
Fig. 4. (a) Diagram showing two different sets of disordered gratings with disorder degree of
Fig. 5. Emission spectra of a 1D disordered QCL without (red curve) and with (violet dashed curve) partial covering by a copper sheet. The pumping current is 4.09 A. All the peaks are labelled by their frequency values in THz. The arrows are referred to in the text.
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Yongquan Zeng, Guozhen Liang, Bo Qiang, Bo Meng, Hou Kun Liang, Shampy Mansha, Jianping Li, Zhaohui Li, Lianhe Li, Alexander Giles Davies, Edmund Harold Linfield, Ying Zhang, Yidong Chong, Qi Jie Wang. Terahertz emission from localized modes in one-dimensional disordered systems [Invited][J]. Photonics Research, 2018, 6(2): 117
Special Issue: OPTICAL MICROCAVITIES
Received: Nov. 3, 2017
Accepted: Dec. 11, 2017
Published Online: Jul. 10, 2018
The Author Email: Qi Jie Wang (qjwang@ntu.edu.sg)