scholarly journals RF Injection of THz QCL Combs at 80 K Emitting over 700 GHz Spectral Bandwidth

Photonics ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Andres Forrer ◽  
Lorenzo Bosco ◽  
Mattias Beck ◽  
Jérôme Faist ◽  
Giacomo Scalari
Keyword(s):  
Optical Transition ◽  
Injection Locking ◽  
Spectral Bandwidth ◽  
Low Loss ◽  
Central Frequency ◽  
Terahertz Emission ◽  
Laser Spectrum ◽  
Quantum Cascade ◽  
Cw Operation ◽  
On Chip

We report about RF injection locking of an homogeneous THz quantum cascade laser operating at 3 THz central frequency. The extremely diagonal nature of the optical transition, combined with low-loss copper-based double-metal waveguides, allow CW operation up to 105 K and CW power in excess of 5.6 mW measured at 80 K. Terahertz emission spanning up to 600 GHz, together with a narrow beatnote, indicate comb operation at 80 K, and strong RF injection clearly modifies the laser spectrum up to 700 GHz spectral bandwidth making these devices ideal candidates for an on-chip dual comb spectrometer.

scholarly journals Graphene Nanoribbon Gap Waveguides for Dispersionless and Low-Loss Propagation with Deep-Subwavelength Confinement

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1302
Author(s):  
Zhiyong Wu ◽  
Lei Zhang ◽  
Tingyin Ning ◽  
Hong Su ◽  
Irene Ling Li ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Potential ◽  
Shape Change ◽  
Optical Switch ◽  
Pulse Amplitude ◽  
Propagation Distance ◽  
Graphene Nanoribbon ◽  
Low Loss ◽  
High Loss ◽  
On Chip

Surface plasmon polaritons (SPPs) have been attracting considerable attention owing to their unique capabilities of manipulating light. However, the intractable dispersion and high loss are two major obstacles for attaining high-performance plasmonic devices. Here, a graphene nanoribbon gap waveguide (GNRGW) is proposed for guiding dispersionless gap SPPs (GSPPs) with deep-subwavelength confinement and low loss. An analytical model is developed to analyze the GSPPs, in which a reflection phase shift is employed to successfully deal with the influence caused by the boundaries of the graphene nanoribbon (GNR). It is demonstrated that a pulse with a 4 μm bandwidth and a 10 nm mode width can propagate in the linear passive system without waveform distortion, which is very robust against the shape change of the GNR. The decrease in the pulse amplitude is only 10% for a propagation distance of 1 μm. Furthermore, an array consisting of several GNRGWs is employed as a multichannel optical switch. When the separation is larger than 40 nm, each channel can be controlled independently by tuning the chemical potential of the corresponding GNR. The proposed GNRGW may raise great interest in studying dispersionless and low-loss nanophotonic devices, with potential applications in the distortionless transmission of nanoscale signals, electro-optic nanocircuits, and high-density on-chip communications.

scholarly journals Spectroscopic Imaging with an Ultra-Broadband (1–4 THz) Compact Terahertz Difference-Frequency Generation Source

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 336
Author(s):  
Atsushi Nakanishi ◽  
Shohei Hayashi ◽  
Hiroshi Satozono ◽  
Kazuue Fujita
Keyword(s):  
Imaging Technique ◽  
Spectroscopic Imaging ◽  
Difference Frequency Generation ◽  
Difference Frequency ◽  
Quality Monitoring ◽  
Terahertz Emission ◽  
Mid Infrared ◽  
Quantum Cascade ◽  
Frequency Generation ◽  
Multi Mode

We demonstrate spectroscopic imaging using a compact ultra-broadband terahertz semiconductor source with a high-power, mid-infrared quantum cascade laser. The electrically pumped monolithic source is based on intra-cavity difference-frequency generation and can be designed to achieve an ultra-broadband multi-mode terahertz emission spectrum extending from 1–4 THz without any external optical setup. Spectroscopic imaging was performed with three frequency bands, 2.0 THz, 2.5 THz and 3.0 THz, and as a result, this imaging technique clearly identified three different tablet components (polyethylene, D-histidine and DL-histidine). This method may be highly suitable for quality monitoring of pharmaceutical materials.

scholarly journals On-chip low loss heralded source of pure single photons

2013 ◽  
Vol 21 (11) ◽  
pp. 13522 ◽  
Author(s):  
Justin B. Spring ◽  
Patrick S. Salter ◽  
Benjamin J. Metcalf ◽  
Peter C. Humphreys ◽  
Merritt Moore ◽  
...  
Keyword(s):  
Single Photons ◽  
Low Loss ◽  
On Chip

scholarly journals 7-cell hollow-core photonic bandgap fiber with broad spectral bandwidth and low loss

2019 ◽  
Vol 27 (8) ◽  
pp. 11608 ◽  
Author(s):  
Xin Zhang ◽  
Shoufei Gao ◽  
Yingying Wang ◽  
Wei Ding ◽  
Xiaocong Wang ◽  
...  
Keyword(s):  
Photonic Bandgap ◽  
Spectral Bandwidth ◽  
Hollow Core ◽  
Low Loss ◽  
Photonic Bandgap Fiber

A novel Ka-band MMIC coupled filter with harmonic suppression

Circuit World ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 169-173
Author(s):  
Jin Guan ◽  
Min Gong ◽  
Bo Gao
Keyword(s):  
Pass Band ◽  
Wave System ◽  
Harmonic Suppression ◽  
Low Loss ◽  
Coupled Line ◽  
Ka Band ◽  
Content Type ◽  
Harmonic Frequencies ◽  
Full Wave ◽  
On Chip

Purpose A novel Ka-band compact parallel-coupled microstrip bandpass filter with harmonic suppression performance has been designed, implemented and tested on GaAs MMIC. Design/methodology/approach This proposed filter consists of modified coupled-line units with T-shaped open-stubs. Findings The proposed filter with T-shaped open-stubs is valuable in performance with low loss at fundamental frequency, suppression at harmonic frequencies and small size. The simulation is based on full-wave electromagnetic analysis and the measurement is based on chip test. It shows an insertion loss below 1.2 dB, return loss better than 20 dB in the pass band and high than 28 dB suppression at harmonic frequencies. Originality/value This Ka-band MMIC filter with harmonic suppression is attractive for the millimeter-wave system.

Injection‐locking characteristics of gain‐guided diode laser arrays with an ‘‘on‐chip’’ master laser

1990 ◽  
Vol 56 (16) ◽  
pp. 1521-1523 ◽  
Author(s):  
J. P. Hohimer ◽  
D. R. Myers ◽  
T. M. Brennan ◽  
B. E. Hammons
Keyword(s):  
Diode Laser ◽  
Injection Locking ◽  
Master Laser ◽  
Laser Arrays ◽  
On Chip
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