- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Continuous Wave THz System Based on an Electrically Tunable Monolithic Dual Wavelength Y-Branch DBR Diode Laser
摘要： We analyse the use of a tunable dual wavelength Y-branch DBR laser diode for THz applications. The laser generates electrically tunable THz difference frequencies in the range between 100 and 300 GHz. The optical beats are tuned via current injection into a micro-resistor heater integrated on top of one of the distributed Bragg reflector (DBR) section of the diode. The laser is integrated in a homodyne THz system employing fiber coupled ion-implanted LT-GaAs log spiral antennas. The applicability of the developed system in THz spectroscopy is demonstrated by evaluating the spectral resonances of a THz filter as well as in THz metrology in thickness determination of a polyethylene sample.
关键词： Homodyne detection,CW THz source,Semiconductor laser
更新于2025-09-19 17:13:59
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Time-resolved measurements of two-color laser light emitted from GaAs/AlGaAs-coupled multilayer cavity
摘要： We measured the two-color laser oscillation from a GaAs/AlGaAs-coupled multilayer cavity at 18 °C–42 °C using current injection. We confirmed simultaneous lasing by detecting the sum frequency generation signal generated by the two-color laser light, and performed time-resolved measurement using a streak camera with a spectrometer. From the observed time transient of the spectra at various temperatures, it is clarified that the temperature change of the device, induced by current injection, modulates the effective cavity length. Therefore, the temperature control of the device is a key factor in stable two-color lasing and THz wave generation.
关键词： time-resolved measurements,sum frequency generation,THz wave generation,GaAs/AlGaAs-coupled multilayer cavity,two-color laser
更新于2025-09-19 17:13:59
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Enhanced growth of Nd <sup>3+</sup> :MgGdB <sub/>5</sub> O <sub/>10</sub> laser crystals with intense multi-wavelength emission characteristics
摘要： Higher quality Nd:GMB crystal was obtained using enhanced K2Mo3O10–B2O3 flux. Intense multi-wavelength emissions reveal the potential in THz technology.
关键词： K2Mo3O10–B2O3 flux,Nd:GMB crystal,multi-wavelength emissions,THz technology
更新于2025-09-19 17:13:59
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Liquid crystal programmable metasurface for terahertz beam steering
摘要： The coding metasurface integrated with tunable materials offers an attractive alternative to manipulate the THz beam dynamically. In this work, we demonstrate a THz programmable metasurface based on liquid crystal. The phase pro?le on the metasurface could be dynamically manipulated by switching the “0” and “1” states of each element. The programmable metasurface could de?ect the THz beam using the designed coding sequence, and a maximum de?ection angle of 32(cid:2) has been achieved. The presented design opens a route of beamforming for THz communication.
关键词： beamforming,programmable metasurface,THz beam steering,liquid crystal
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - High-Power 0.33 mW Broadband THz Source Driven by an Ultrafast Yb-Based Thin-Disk Laser Oscillator
摘要： THz-time-domain spectroscopy (THz-TDS) is a well-established tool for characterizing material properties and investigating dynamics of complex molecular systems. As the broadband THz generation typically relies on sub-100-fs laser pulses, most systems are currently driven by Ti:sapphire lasers. In the last years there has been a strong effort to replace Ti:sapphire systems with power-scalable Yb-based directly diode-pumped solid-state lasers (DPSSLs). Ultrafast DPSSLs generate higher average power with lower complexity and better efficiency. However, their potential for high-power broadband THz operation has not yet been fully exploited. This study shows the high potential of TDL oscillator driven systems for high-power broadband THz generation. Thanks to the power scalability of the TDL technology we expect broadband THz sources operating at MHz repetition rates and several mW average power to be soon within reach.
关键词： THz-time-domain spectroscopy,thin-disk laser oscillator,broadband THz generation,Yb-based lasers
更新于2025-09-16 10:30:52
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Selective Absorption of Photonic Crystal with Graphene
摘要： Selective absorption of photonic crystal with graphene is studied. The Photonic Crystal at THz regime with permittivity 4.2 is designed and validated with rigorous coupled-wave analysis method (RCWA) and finite element method (FEM). The selective absorption is achieved by combining the Photonic Crystal with Graphene. The selective absorption is explained with Fano resonance fitting method.
关键词： RCWA,FEM,THz,Selective absorption,Photonic crystal (PC),Graphene
更新于2025-09-16 10:30:52
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Layered THz waveguides for SPPs, filter and sensor applications
摘要： Theory of five kinds of layered structure THz waveguides is presented. In these waveguides, the modified and hybrid THz surface plasmon-polaritons (SPPs) are researched in detail. On these modes, the effects of material in each layer are discussed. The anti-resonant reflecting mechanism is also discussed in these waveguides. The mode characteristics of both TM mode and TE mode are analyzed for guiding TM mode with low loss and TE modes with huge loss in one waveguide: the TE modes filter application is put forward. The mode characteristics for one waveguide have useful sensor applications: for TE1 mode, we find that the low cut-off frequency has a sensitivity (S) to the refractive index of the dielectric slab. The highest S can be 666.7 GHz/RIU when n2 = 1.5, w = 0 and t = 0.1 mm. We believe these results are very useful for designing practical THz devices for SPPs, filter and sensor applications.
关键词： Sensors,THz waveguides,Surface plasmon-polaritons,Filters
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - THz-wave Signal Generation based on Optical Frequency Comb by One MZM
摘要： We propose a novel Terahertz-wave (THz-wave) signal generation based on optical frequency comb by only one single-drive MZM in 0.4 THz band by simulation. Bit-error-ratio (BER) curves of the QPSK and 16QAM signal proved feasible.
关键词： Modulation,THz-wave signal,Optical frequency comb
更新于2025-09-16 10:30:52
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - A Graphene Self-Switching Diode Bridge Rectifier
摘要： Here we present theory and measurements for a bridge rectifier formed from arrays of graphene self-switching diodes (GSSDs). Graphene’s extremely high carrier mobility allows GSSDs to work at THz frequencies, with the bridge rectifier structure allowing for full wave rectification of an AC signal. We derive an equation for the voltage output of a GSSD bridge rectifier, predicting a quadratic dependence on input current. This relationship is confirmed using AC and DC measurements. The fabricated rectifier has a high room temperature intrinsic responsivity of 3,230 V/W at low frequency and a low noise equivalent power of 7.0 pW/Hz1/2. Moving forward, similar devices using CVD graphene have been tested and shown to function with high responsivity.
关键词： THz frequencies,responsivity,bridge rectifier,self-switching diodes,graphene
更新于2025-09-16 10:30:52
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Including the Effects of Covering Layers in the Determination of Graphene Conductivity from THz-TDS Measurements
摘要： We investigate the effects of covering layers on the determination of graphene conductivity from THz-TDS measurements. Especially the errors arising from the common approach to neglect those layers in the determination process are addressed. To counteract those errors an expanded determination method, based on the classical thin-film approach is introduced.
关键词： thin-film approximation,graphene conductivity,THz-TDS measurements,covering layers
更新于2025-09-16 10:30:52