Terahertz coherent receiver using a single resonant tunnelling diode

AbstractTowards exploring advanced applications of terahertz (THz) electromagnetic waves, great efforts are being applied to develop a compact and sensitive THz receiver. Here, we propose a simple coherent detection system using a single resonant tunnelling diode (RTD) oscillator through self-oscillating mixing with an RTD oscillator injection-locked by a carrier wave. Coherent detection is successfully demonstrated with an enhancement in the sensitivity of >20 dB compared to that of direct detection. As a proof of concept, we performed THz wireless communications using an RTD coherent receiver and transmitter. We achieved 30-Gbit/s real-time error-free transmission, which is the highest among all electronic systems without error correction to date. Our results show that the proposed system can reduce the size and power consumption of various THz systems including sensing, imaging and ranging, which would enable progress to be made in a wide range of fields in such as material science, medicine, chemistry, biology, physics, astronomy, security, robotics and motor vehicle.

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Combined Effect of ASE Noise and SRS Induced Crosstalk on the BER Performance of a Single Span WDM System with Raman Amplifier Using Heterodyne Coherent Detection

Journal of Optical Communications ◽

10.1515/joc-2018-0012 ◽

2019 ◽

Vol 0 (0) ◽

Cited By ~ 1

Author(s):

F.H. Tithi ◽

S.P. Majumder

Keyword(s):

Direct Detection ◽

Stimulated Raman Scattering ◽

Detection System ◽

Combined Effect ◽

Coherent Detection ◽

Heterodyne Receiver ◽

System Parameters ◽

Raman Amplifier ◽

Transmission Distance ◽

Channel Bandwidth

AbstractAnalysis is presented to evaluate numerically the combined effect of amplified spontaneous emission (ASE) and stimulated Raman scattering (SRS) on the bit error rate performance of a WDM transmission system with Raman amplifier using heterodyne receiver. The results are compared with those for a WDM system reported with direct detection receiver for different system parameters. It is observed that coherent heterodyne system is less affected by the crosstalk due to combined effect of ASE and SRS compared to direct detection. It is noticed that allowable transmission distance is 170 km, and 166 km of WDM channels for 8, and 16, respectively, when coherent heterodyne receiver is and with pump power of 10 mW and channel bandwidth of 12.5 GHz. The corresponding transmission distance is 60 km and 10 km, respectively, for direct detection system already reported.

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Performance analysis of direct detection and coherent detection system for optical OFDM using QAM and DPSK

IOSR Journal of Engineering ◽

10.9790/3021-03722429 ◽

2013 ◽

Vol 3 (7) ◽

pp. 24-29

Author(s):

Veneetha Nair

Keyword(s):

Performance Analysis ◽

Direct Detection ◽

Detection System ◽

Coherent Detection ◽

Optical Ofdm

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Microwaves: Application in Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158248 ◽

1990 ◽

Vol 48 (3) ◽

pp. 140-141

Author(s):

Anthony S-Y Leong ◽

David W Gove

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Chemical Reactions ◽

Electromagnetic Waves ◽

Tissue Fixation ◽

Primary Method ◽

Dipolar Molecules ◽

Wide Range ◽

Time Required ◽

Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

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Resonant-tunnelling diode oscillator using a slot-coupled quasioptical open resonator

Electronics Letters ◽

10.1049/el:19910406 ◽

1991 ◽

Vol 27 (8) ◽

pp. 647 ◽

Cited By ~ 4

Author(s):

K.D. Stephan ◽

E.R. Brown ◽

C.D. Parker ◽

W.D. Goodhue ◽

C.L. Chen ◽

...

Keyword(s):

Open Resonator ◽

Resonant Tunnelling ◽

Diode Oscillator ◽

Resonant Tunnelling Diode

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Accurate Power-Efficient Format-Scalable Multi-Parallel Optical Digital-to-Analogue Conversion

Photonics ◽

10.3390/photonics8020038 ◽

2021 ◽

Vol 8 (2) ◽

pp. 38

Author(s):

Moshe Nazarathy ◽

Ioannis Tomkos

Keyword(s):

Energy Efficiency ◽

Direct Detection ◽

Coherent Detection ◽

Performance Limits ◽

Optical Modulators ◽

Analog To Digital ◽

Power Efficient ◽

Optical Signals ◽

Digital To Analog Converters ◽

Optical Analog

In optical transmitters generating multi-level constellations, optical modulators are preceded by Electronic Digital-to-Analog-Converters (eDAC). It is advantageous to use eDAC-free Optical Analog to Digital Converters (oDAC) to directly convert digital bitstreams into multilevel PAM/QAM optical signals. State-of-the-art oDACs are based on Segmented Mach-Zehnder-Modulators (SEMZM) using multiple modulation segments strung along the MZM waveguides to serially accumulate binary-modulated optical phases. Here we aim to assess performance limits of the Serial oDACs (SEMZM) and introduce an alternative improved Multi-Parallel oDAC (MPoDAC) architecture, in particular based on arraying multiple binary-driven MZMs in parallel: Multi-parallel MZM (MPMZM) oDAC. We develop generic methodologies of oDAC specification and optimization encompassing both SEMZM and MPMZM options in Direct-Detection (DD) and Coherent-Detection (COH) implementations. We quantify and compare intrinsic performance limits of the various serial/parallel DD/COH subclasses for general constellation orders, comparing with the scant prior-work on the multi-parallel option. A key finding: COH-MPMZM is the only class synthesizing ‘perfect’ (equi-spaced max-full-scale) constellations while maximizing energy-efficiency-SEMZM/MPMZM for DD are less accurate when maximal energy-efficiency is required. In particular, we introduce multiple variants of PAM4|8 DD and QAM16|64 COH MPMZMs, working out their accuracy vs. energy-efficiency-and-complexity tradeoffs, establishing their format-reconfigurability (format-flexible switching of constellation order and/or DD/COH).

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TLP-IDS: A Two-layer Intrusion Detection System for Integrated Electronic Systems

2020 International Symposium on Reliable Distributed Systems (SRDS) ◽

10.1109/srds51746.2020.00028 ◽

2020 ◽

Author(s):

Xiaoxia Liu ◽

Daojing He ◽

Yun Gao ◽

Sencun Zhu ◽

Sammy Chan

Keyword(s):

Intrusion Detection ◽

Intrusion Detection System ◽

Detection System ◽

Electronic Systems

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Detection and characterization of Leptospira spp. in dogs diagnosed with kidney and/or liver disease in Selangor, Malaysia

Journal of Veterinary Diagnostic Investigation ◽

10.1177/10406387211024575 ◽

2021 ◽

pp. 104063872110245

Author(s):

Sabri A. Rahman ◽

Kuan H. Khor ◽

Siti Khairani-Bejo ◽

Seng F. Lau ◽

Mazlina Mazlan ◽

...

Keyword(s):

Liver Disease ◽

Mortality Rate ◽

Direct Detection ◽

Bacterial Disease ◽

Pathogenic Leptospira ◽

Wide Range ◽

Leptospira Spp ◽

Rrna Sequencing ◽

The Common

Leptospirosis is a serious bacterial disease that affects both humans and animals. A wide range of symptoms have been described in humans; the disease in dogs is commonly associated with kidney and/or liver disease. In Malaysia, information about the common serovars infecting dogs is limited. Therefore, we investigated the occurrences of leptospirosis in 124 pet dogs diagnosed with kidney and/or liver disease. Blood, urine, abdominal effusion, and/or kidney and liver were collected from the dogs. Based on microscopic agglutination testing, 53 of 124 (42.7%) dogs were seropositive for leptospiral exposure. Sera were frequently positive to serovars Bataviae ( n = 12), Javanica ( n = 10), and Icterohaemorrhagiae ( n = 10). Direct detection using PCR showed that 42 of 124 (33.9%) of the whole blood and 36 of 113 (31.9%) urine samples were positive for pathogenic Leptospira spp. By PCR, 2 of 23 (9.1%) kidney and 2 of 23 (9.1%) liver were positive for pathogenic Leptospira spp. Abdominal effusion from 4 dogs were PCR-positive for pathogenic Leptospira spp. The species detected were L. interrogans, L. borgpetersenii, L. kirschneri, and L. kmetyi by partial 16S rRNA sequencing. We further identified and characterized 11 Leptospira spp. isolates from 8 dogs as serovars Bataviae, Javanica, and Australis. The mortality rate of the Leptospira-infected dogs was high (18 of 53; 34%).

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