Results 81 to 90 of about 36,720 (261)

Photon‐Sphere Modes in Curved Optical Microcavities: A Black‐Hole Analogue Laser

open access: yesAdvanced Science, EarlyView.
An optical analogue of a Schwarzschild black hole is realized using curved microcavities that preserve light‐like geodesics. A new family of laser modes confined around the photon sphere is identified alongside conventional whispering‐gallery modes. Analytical theory, numerical simulations, and experiments reveal curvature‐induced confinement, enabling
Chenni Xu   +9 more
wiley   +1 more source

Y-coupled Terahertz Quantum Cascade Lasers [PDF]

open access: yesConference on Lasers and Electro-Optics 2012, 2012
Here we demonstrate a Y coupled terahertz (THz) quantum cascade laser (QCL) system. The two THz QCLs working around 2.85 THz are driven by independent electrical pulsers. Total peak THz output power of the Y system, with both arms being driven synchronously, is found to be more than the linear sum of the peak powers from the individual arms; 10.4 mW ...
Chakraborty, Subhasish   +4 more
openaire   +2 more sources

Transient Terahertz Oscillations During Photoinduced Polarization Topology Reconfiguration in Ferroelectric Superlattices

open access: yesAdvanced Science, EarlyView.
Terahertz resonances in crystalline heterostructures could close a spectral gap between conventional electronics and photonics while opening new windows on non‐equilibrium lattice dynamics. Femtosecond optical screening of the depolarization field in epitaxial PbTiO3/SrTiO3 superlattices launches a collective polar mode that oscillates near 1 THz and ...
Deepankar Sri Gyan   +13 more
wiley   +1 more source

Contactless Terahertz “Fiber Squeezer” for Tunable Dispersion Engineering in Unclad Silicon Dielectric Waveguides

open access: yesAdvanced Photonics Research
The advancement of terahertz technology is impeded by a lack of viable options for dynamic reconfigurability in compact systems with fixed low‐loss interconnect.
Daniel Headland   +5 more
doaj   +1 more source

Characteristics of transition metal dichalcogenides in optical pumped modulator of terahertz wave

open access: yesAIP Advances, 2020
To study the characteristics of transition metal dichalcogenides (TMDCs) in the THz regime, several kinds of terahertz modulators based on TMDCs were fabricated.
Zhiyuan Fan   +7 more
doaj   +1 more source

Optical thin film coated organic nonlinear crystal for efficient terahertz wave generation

open access: yesScientific Reports, 2022
In the process of terahertz (THz) wave generation via optical rectification of infrared femtosecond pulses in a non-linear optical crystal, the power of terahertz wave is directly proportional to the square of the optical pump power.
Hirohisa Uchida   +5 more
doaj   +1 more source

Dirac Surface‐State Driven Broad Spectral Band Low Quantum Energy Photoresponse in Quaternary Topological BiSbSe2Te

open access: yesAdvanced Science, EarlyView.
Quaternary topological BiSbSe2Te are synthesized and demonstrates a broad spectral band photoresponse, ranging from infrared to terahertz and to millimeter waves, with a particular excellence on detection of low quantum energy terahertz photons. The observed photoresponse is attributed to the excitation of plasmonic nonequilibrium electrons originating
Tianning Zhang   +14 more
wiley   +1 more source

Self-normalizing phase measurement in multimode terahertz spectroscopy based on photomixing of three lasers

open access: yes, 2014
Photomixing of two near-infrared lasers is well established for continuous-wave terahertz spectroscopy. Photomixing of three lasers allows us to measure at three terahertz frequencies simultaneously.
A. Roggenbuck   +7 more
core   +1 more source

Terahertz tomography using quantum-cascade lasers [PDF]

open access: yesOptics Letters, 2012
The interfaces of a dielectric sample are resolved in reflection geometry using light from a frequency agile array of terahertz quantum-cascade lasers. The terahertz source is a 10-element linear array of third-order distributed-feedback QCLs emitting at discrete frequencies from 2.08 to 2.4 THz. Emission from the array is collimated and sent through a
Kao, Tsung-Yu   +4 more
openaire   +3 more sources

Retina‐Inspired Bi‐Based Terahertz Photonic Neuromorphic Devices

open access: yesAdvanced Science, EarlyView.
Combined with effective band alignment and substrate engineering, bismuth materials are introduced to form terahertz photonic bio‐inspired devices with picosecond short‐term plasticity to enable multi‐scene visual perception. Thus obtained hardware through the terahertz optical neural network (THz‐ONN) demonstrates high recognition accuracy, providing ...
Pujing Zhang   +14 more
wiley   +1 more source

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