Article
Optics
Chao Ning, Tian Yu, Shuman Liu, Jinchuan Zhang, Lijun Wang, Junqi Liu, Ning Zhuo, Shenqiang Zhai, Yuan Li, Fengqi Liu
Summary: We demonstrate GaSb-based interband cascade lasers with high output power and good reliability.
CHINESE OPTICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Ping Gong, Yiming Wang, Zhixuan Er, Liang Xie
Summary: This paper demonstrates the integration of multiwavelength distributed feedback quantum cascade lasers (QCLs) in C-mount packages for portable gas sensors. Thermal management is performed through modeling and experimental verification. The integrated QCLs have wavelengths of 4492, 5459, 6224, and 9640 nm, with a wavelength tuning range and optical power of no less than 6.5 nm and 65 mW, respectively. The dimensions of the integrated sources are 40 mmx40 mmx80 mm.
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
(2023)
Article
Optics
L. M. Kruger, J. Hillbrand, J. Heidrich, M. Beiser, R. Weih, J. Koeth, C. R. Phillips, B. Schwarz, G. Strasser, U. Keller
Summary: Interband cascade infrared photodetectors (ICIPs) combine interband optical transitions with fast intraband transport to achieve high-frequency and broad-wavelength operation at room temperature. Investigation of the bias-dependent electronic impulse response of ICIPs reveals the impact of reverse bias on saturation power and responsivity, showing an increase in these parameters with increasing reverse bias voltage.
Article
Engineering, Electrical & Electronic
Bin-Bin Zhao, Xing-Guang Wang, Cheng Wang
Summary: The study demonstrates that tilted optical feedback with a misaligned reflection mirror can trigger quantum cascade lasers to generate low-frequency oscillations, including irregular pulse oscillations and square wave oscillations. The oscillation period is in the microsecond range, generally decreasing with increasing tilt angle, and the duty cycle of the square waves is tunable through varying the tilt angle. It is also noted that weak feedback strength or low pump current results in rare occurrence of pulse oscillations.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Yuanhao Zhang, Fan Yang, Gonghai Liu, Guojiong Li, Minwen Xiang, Qiaoyin Lu, John F. Donegan, Weihua Guo
Summary: In this work, a 1.3-μm directly modulated laser with a ridge waveguide distributed feedback region and a buried waveguide spot-size-converter region was demonstrated. The integration of this spot-size-converter improved beam profile and power coupling efficiency, while the fabrication cost was reduced. The fabricated laser achieved a nearly circular beam profile and more than 70% improvement in power coupling.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Jae Ha Ryu, Chris Sigler, Jeremy D. Kirch, Thomas Earles, Dan Botez, Luke J. Mawst
Summary: Grating-coupled, surface-emitting quantum-cascade lasers of linear geometry generally operate in an antisymmetric mode, which can be suppressed by designing gratings favoring symmetric-mode operation or having a central pi-phaseshift. Simulations and analysis show that the latter design has higher fabrication tolerance and can operate in a single-lobe beam pattern up to 0.63 W CW.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Tianrui Zhai, Xiaojie Ma, Liang Han, Shuai Zhang, Kun Ge, Yanan Xu, Zhiyang Xu, Libin Cui
Summary: This study demonstrates the assembly of a DFB laser on the sidewalls of an optical fiber using simple fabrication techniques. The directional lasing from the fiber facet shows a small solid divergence angle due to two-dimensional light confinement in the fiber waveguide. This technique offers the potential to integrate multiple DFB lasers on the same optical fiber sidewall for directional emission in applications such as networking, optical sensing, and power delivery.
Article
Optics
Hongzhou Bai, Guowen Liu, Kai Wang, Gaolei Chang, Shanzhi Zang, Cheng Tan, Lianghua Gan, Yueheng Zhang, Li He, Gangyi Xu
Summary: We report on the operation of 1D terahertz quantum cascade microlaser arrays working on various bound states in the continuum. By breaking the inversion symmetry of the microlaser array, we first created a quasi-bound state in the continuum, enabling flexible control of the radiation efficiency. We then hybridized the quasi-bound state with a high-Q surface plasmon polariton mode to further increase the operating temperature of the microlaser.
Article
Chemistry, Multidisciplinary
Binbin Zhao, Yibo Peng, Xingguang Wang, Cheng Wang
Summary: This study focuses on the modulation characteristics of period-one oscillations in a quantum cascade laser subjected to tilted optical feedback. The electrical signal at the oscillation frequency is more than 50 dB higher than the noise level, with an electrical linewidth less than 2.0 kHz, about four orders of magnitude narrower than the optical linewidth of the free-running laser. Additionally, simulations show that the period-one oscillations induce both amplitude modulation and frequency modulation.
APPLIED SCIENCES-BASEL
(2021)
Article
Optics
Shuai Wang, Zun-Ren Lv, Qiu-Lu Yang, Sheng-Lin Wang, Hong-Yu Chai, Lei Meng, Dan Lu, Chen Ji, Xiao-Guang Yang, Tao Yang
Summary: A high-power, ultra-low-noise 1.3 μm InAs/GaAs QD distributed feedback laser is demonstrated by combining atom-like quantum dot materials and advanced lateral gratings. This laser achieves stable single-longitudinal-mode output power of 100 mW from 25 celcius to 85 celcius, with a maximum side mode suppression ratio of 62.6 dB. It also demonstrates a high temperature stability, a record-narrow intrinsic linewidth of 1.62 kHz, and a strong tolerance to external optical feedback.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Qi Yang, Jicheng Zhang, Xuemin Wang, Zhiqiang Zhan, Tao Jiang, Jia Li, Ruijiao Zou, Keyu Li, Fengwei Chen, Weidong Wu
Summary: This work presents a dual ridge terahertz quantum cascade laser lasing at 3.1 THz and analyzes its performance in detail. The experimental results provide a reference for realizing high-power terahertz quantum cascade lasers and offer guidance for the structural design of multiple ridges or laser arrays.
Article
Multidisciplinary Sciences
Paolo Micheletti, Urban Senica, Andres Forrer, Sara Cibella, Guido Torrioli, Martin Frankie, Mattias Beck, Giacomo Scalari, J'rome Faist
Summary: Quantum cascade lasers (QCLs) offer an intriguing opportunity for generating on-chip optical dissipative Kerr solitons (DKS). Recent observations of DKS in mid-infrared ring QCLs have paved the way for achieving DKS at longer wavelengths. Terahertz ring QCLs with anomalous dispersion were realized using a waveguide planarization technology platform. A concentric coupled waveguide approach was implemented for dispersion compensation, while a passive broadband bullseye antenna improved power extraction and far field. The presence of solitons was confirmed through hysteric behavior, phase difference measurements, and intensity time profile reconstruction, which matched well with numerical simulations based on the Complex Ginzburg-Landau Equation (CGLE).
Article
Optics
Kun Tian, Yonggang Zou, Linlin Shi, He Zhang, Yingtian Xu, Jie Fan, Hui Tang, Xiaohui Ma
Summary: A novel broad-area distributed feedback laser with high-order surface curved gratings has been successfully fabricated using standard near ultraviolet lithography. The laser achieves simultaneous increase in output power and mode selection by utilizing a broad-area ridge and an unstable cavity structure consisting of curved gratings and a high-reflectivity coated rear facet. Suppression of high-order lateral modes is achieved through current injection/non-injection regions and asymmetric waveguides. The laser, emitting at around 1070nm, exhibits a spectral width of 0.138nm and a maximum output power of 915mW. The threshold current and side-mode suppression ratio of the device are 370mA and 33 dB, respectively. The simple manufacturing process and stable performance make this high-power laser promising for applications in light detection and ranging, laser pumps, optical disk access, etc.
Article
Physics, Multidisciplinary
Lei Ge, Ning Yang, Jian Wang, Weidong Chu, Suqing Duan, Yan Xie, Yingxin Wang, Lianhe Li, Edmund Linfield
Summary: This study investigates the output characteristics of self-mixing interference in distributed feedback (DFB) terahertz quantum cascade lasers (QCLs). It is found that a mode hopping phenomenon occurs when the DFB coupling factor changes from index-coupling to gain-coupling, leading to significant changes in the self-mixing signals. The study also shows that the characteristics of self-mixing signals vary with the modulation of the coupling factor's argument and modulus.
FRONTIERS IN PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Lebin Nie, Wai Kit Ng, ZhiFu Liang, Xingang Ren, Tingbin Yang, Guanding Mei, Chi Wah Leung, Kam Sing Wong, Wallace C. H. Choy
Summary: The upside-down molding method used to fabricate photonic resonators on perovskites allows for some degree of control over pattern geometry, reveals the impact of capillary force during imprinting, and enables control over waveguide layer thickness through inversion of the perovskite membranes.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Applied
Miriam Giparakis, Hedwig Knoetig, Hermann Detz, Maximilian Beiser, Werner Schrenk, Benedikt Schwarz, Gottfried Strasser, Aaron Maxwell Andrews
Summary: Quantum cascade detectors (QCDs) are presented utilizing an InAs/AlAs0.16Sb0.84 lattice matched to an InAs substrate, showing low effective electron mass and high conduction band offset for high optical absorption strength. The QCD has a peak spectral response at 2.7 mu m (0.459 eV) and a peak specific detectivity of 1.14 x 10^8 Jones.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Analytical
Alicja Dabrowska, Mauro David, Stephan Freitag, Aaron Maxwell Andrews, Gottfried Strasser, Borislav Hinkov, Andreas Schwaighofer, Bernhard Lendl
Summary: Mid-infrared chemical sensors based on quantum cascade technology were developed for broadband detection of aqueous samples targeting bovine milk proteins. The setup combined a tunable quantum cascade laser with a spectrally tailored in-house fabricated quantum cascade detector, showing similar performance to a high-end FTIR spectrometer. The study highlights the potential of quantum cascade detectors in next-generation MIR liquid-phase chemical sensors with low noise and high dynamic range.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Physics, Applied
M. Jaidl, N. Opacak, M. A. Kainz, D. Theiner, B. Limbacher, M. Beiser, M. Giparakis, A. M. Andrews, G. Strasser, B. Schwarz, J. Darmo, K. Unterrainer
Summary: This paper demonstrates terahertz quantum cascade lasers realized in ideal ring resonators without discontinuities, achieved by mounting the rings upside down on a silicon substrate using a die-bonding technique. The lasers emit light around 3.8 THz, show reduced threshold current densities, and exhibit frequency comb formation.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
M. A. U. R. O. DAVID, D. A. V. I. D. E. DISNAN, A. N. N. A. LARDSCHNEIDER, D. O. M. I. N. I. K. WACHT, H. A. N. H. T. HOANG, G. E. O. R. G. RAMER, H. E. R. M. A. N. N. DETZ, B. E. R. N. H. A. R. D. LENDL, U. L. R. I. C. H. SCHMID, G. O. T. T. F. R. I. E. D. STRASSER, B. O. R. I. S. L. A. V. HINKOV
Summary: This study investigates the optical and structural properties of spin-coated linear low-density polyethylene films fabricated under humidity-controlled conditions. The non-linear behavior of film thickness on polymer concentration dependence is observed, allowing for predictive concentration-dependent thickness deposition. The films exhibit nanometer-scale surface roughness and good stability when exposed to solvents. Mid-infrared ellipsometry measurements confirm the broad transparency range of the films, making them suitable for use in photonic integrated circuits.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Physics, Applied
Sandro Dal Cin, Florian Pilat, Ales Konecny, Nikola Opacak, Gottfried Strasser, Benedikt Schwarz
Summary: This study demonstrates coherent control of longitudinal laser modes in a quantum cascade laser, enabling control over the transverse modes. By modulating the laser within a specific frequency range and applying sufficient power, reliable operation of fundamental transverse modes with single-lobe, Gaussian-like characteristics in the far-field can be achieved.
APPLIED PHYSICS LETTERS
(2022)
Article
Multidisciplinary Sciences
Borislav Hinkov, Florian Pilat, Laurin Lux, Patricia L. Souza, Mauro David, Andreas Schwaighofer, Daniela Ristanic, Benedikt Schwarz, Hermann Detz, Aaron M. Andrews, Bernhard Lendl, Gottfried Strasser
Summary: The authors demonstrate sensitive real-time reaction monitoring of conformational changes in protein solution using a fingertip-sized mid-infrared lab-on-a-chip.
NATURE COMMUNICATIONS
(2022)
Article
Crystallography
E. Bakali, W. Artner, M. Beiser, J. Bernardi, H. Detz, G. Eguchi, A. Foelske, M. Giparakis, C. Herzig, A. Limbeck, H. Nguyen, L. Prochaska, A. Prokofiev, M. Sauer, S. Schwarz, W. Schrenk, G. Strasser, R. Svagera, M. Taupin, A. S. Thirsfeld, M. Waas, X. Yan, D. A. Zocco, A. M. Andrews, S. Paschen
Summary: The study focused on the characteristics of YbRh2Si2 thin films grown by molecular beam epitaxy and the quality of the highly stoichiometric sample. The results showed that the highly stoichiometric sample exhibited the best quality, with the highest intensity ratio, highest ratio, smallest surface roughness, and minimal surface defects.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Optics
G. Marschick, M. David, E. Arigliani, N. Opacak, B. Schwarz, M. Giparakis, A. Delga, M. Lagree, T. Poletti, V. Trinite, A. Evirgen, B. Gerard, G. Ramer, R. Maulini, J. Butet, S. Blaser, A. M. Andrews, G. Strasser, B. Hinkov
Summary: Quantum cascade detectors (QCDs) operate at zero external bias with low dark-current, making them suitable for heterodyne detection in long-wave infrared (LWIR) free space optical communication systems. The study compares single and multi-period QCDs to optimize responsivity and noise behavior, revealing significant differences in room-temperature responsivities between the two types of devices.
Article
Physics, Multidisciplinary
Ching-Chen Yeh, Siang-Chi Wang, Shun-Tsung Lo, Gil-Ho Kim, D. A. Ritchie, Gottfried Strasser, Chi-Te Liang
Summary: We have observed a temperature-independent point Bc in the longitudinal resistance Rxx of a GaAs-based two-dimensional electron gas during the quantum Hall plateau-plateau transition. This discovery allows us to re-examine the spin-degenerate plateau-plateau transition and calculate the critical exponent kappa by measuring the movement of the Rxx peak with respect to Bc at different temperatures. We propose measuring the maximum derivative of Hall resistivity d(rho xy)/dB similar to T-kappa as well as the movement of Rxx at different temperatures to determine kappa s using two independent methods. When the peak movement deviates significantly from Bc, a kappa value of 0.54 +/- 0.04 can be measured, which is considerably different from the value (0.21 +/- 0.02) in some spin-degenerate systems.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Michael Jaidl, Maximilian Beiser, Miriam Giparakis, Martin Alexander Kainz, Dominik Theiner, Benedikt Limbacher, Marie Christine Ertl, Aaron Maxwell Andrews, Gottfried Strasser, Juraj Darmo, Karl Unterrainer
Summary: This study presents a heterogeneous terahertz quantum cascade laser consisting of five individual active regions based on a three-well, LO-phonon depopulation design. The lasers can operate in both pulsed and continuous-wave modes, emitting in a spectral range from 1.9 to 4.5 THz, with broad bandwidth.
Article
Biochemical Research Methods
Florian Pilat, Benedikt Schwarz, Bettina Baumgartner, Daniela Ristanic, Hermann Detz, Aaron M. M. Andrews, Bernhard Lendl, Gottfried Strasser, Borislav Hinkov
Summary: Quality control of liquids plays a crucial role in analytical chemistry, and the gold standard for measuring residual water in organic solvents and pharmaceutical applications is Karl Fischer titration. A high-performance lab-on-a-chip sensor based on mid-IR spectroscopy is proposed for real-time analysis of residual water concentration in isopropyl alcohol. Two experiments demonstrate its ability to detect water content with high sensitivity and rapid response time. The sensor achieves a limit of detection between 120 ppm and 150 ppm for the flow cell configuration and 1.5 x 10(-2)%(vol) to 19%(vol) in the in situ configuration.
