High-performance THz QCL frequency combs (Conference Presentation)

2020 ◽  
Author(s):  
Andres Forrer ◽  
Lorenzo Bosco ◽  
Mattias Beck ◽  
Jérôme Faist ◽  
Giacomo Scalari
Keyword(s):  
High Performance ◽  
Frequency Combs

scholarly journals Dioxin and Related Compound Detection: Perspectives for Optical Monitoring

2019 ◽  
Vol 20 (11) ◽  
pp. 2671 ◽  
Author(s):  
Barbara Patrizi ◽  
Mario Siciliani de Cumis ◽  
Silvia Viciani ◽  
Francesco D’Amato
Keyword(s):  
High Performance ◽  
High Resolution Mass Spectrometry ◽  
Human Life ◽  
Endocrine System ◽  
Developmental Issues ◽  
Frequency Combs ◽  
Sensitivity And Selectivity ◽  
Short Time ◽  
The Impact ◽  
Related Compounds

Dioxins and related compounds are environmental xenobiotics that are dangerous to human life, due to the accumulation and persistence in the environment and in the food chain. Cancer, reproductive and developmental issues, and damage to the immune system and endocrine system are only a few examples of the impact of such substances in everyday life. For these reasons, it is fundamental to detect and monitor these molecules in biological samples. The consolidated technique for analytical evaluation is gas chromatography combined with high-resolution mass spectrometry. Nowadays, the development of mid-infrared optical components like broadband laser sources, optical frequency combs, high performance Fourier-transform infrared spectroscopy, and plasmonic sensors open the way to new techniques for detection and real time monitoring of these organic pollutants in gaseous or liquid phase, with sufficient sensitivity and selectivity, and in short time periods. In this review, we report the latest techniques for the detection of dioxins, furans and related compounds based on optical and spectroscopic methods, looking at future perspectives.

scholarly journals High performance quantum cascade laser frequency combs at λ ∼ 6 μm based on plasmon-enhanced dispersion compensation

2020 ◽  
Vol 28 (14) ◽  
pp. 20714
Author(s):  
Sargis Hakobyan ◽  
Richard Maulini ◽  
Stéphane Blaser ◽  
Tobias Gresch ◽  
Antoine Muller
Keyword(s):  
Quantum Cascade Laser ◽  
High Performance ◽  
Dispersion Compensation ◽  
Laser Frequency ◽  
Frequency Combs ◽  
Quantum Cascade

High performance quantum cascade laser frequency combs at λ ~ 6 pm

2020 ◽  
Author(s):  
Sargis Hakobyan ◽  
Richard Maulini ◽  
Stéphane Blaser ◽  
Tobias Gresch ◽  
Yan Francescato ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
High Performance ◽  
Laser Frequency ◽  
Frequency Combs ◽  
Quantum Cascade

Basic Study on Polishing Technology for Microcavity With Electrically Controlled Slurry

2020 ◽  
Author(s):  
Yuka Hayama ◽  
Yasuhiro Kakinuma
Keyword(s):  
High Performance ◽  
Optical Signal ◽  
Basic Study ◽  
Suitable Material ◽  
Frequency Combs ◽  
Optical Microcavity ◽  
Precision Turning ◽  
Short Period ◽  
Wide Range ◽  
Ultra Precision

Abstract Optical microcavity, which can localize light at a certain spot for a short period of time, have a wide range of applications, such as optical signal processing and optical frequency combs. Single crystal calcium fluoride is one of the most suitable material for fabricating optical microcavity due to its excellent optical properties; however, it cannot be manufactured by chemical processes such as etching due to its crystal anisotropy. Currently, high performance optical microcavities are fabricated by ultra-precision turning followed by a hand polishing process because it has complex shape with a size of micro order. However, hand polishing deteriorates the shape made by ultra-precision turning and has a low reproductivity. Therefore, a development of a soft mechanical polishing method to replace hand polishing is strongly desired. Electrically controlled slurry technique is a promising approach in polishing of microparts, where AC electric field is applied to the slurry in order to control the distribution of abrasives to improve the polishing properties in free abrasive polishing. In this study, polishing by applying electrically controlled slurry was conducted for microcavity and the influence of frequency and applied voltage were investigated. From the experimental results, clear differences in the surface quality of microcavity were shown according to amplitude of AC voltage and its frequency.

scholarly journals All-fibre heterogeneously-integrated frequency comb generation using silicon core fibre

2021 ◽  
Author(s):  
Ronit Sohanpal ◽  
Haonan Ren ◽  
Li Shen ◽  
Callum Deakin ◽  
Alexander Heidt ◽  
...  
Keyword(s):  
Signal Processing ◽  
High Power ◽  
High Performance ◽  
Frequency Comb ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Frequency Combs ◽  
Core Fibre ◽  
Comb Generation ◽  
Technical Features

Abstract Originally developed for metrology, optical frequency combs are becoming increasingly pervasive in a wider range of research topics including optical communications, spectroscopy, and radio or microwave signal processing. However, application demands in these fields can be more challenging as they require compact sources with a high tolerance to temperature variations that are capable of delivering flat comb spectra, high power per tone, narrow linewidth and high optical signal-to-noise ratio (OSNR). To date, there has not been a frequency comb technology that is able to simultaneously achieve all these requirements. This work reports the generation of a flat, high power frequency comb in the telecom band using a 17-mm fully-integrated silicon core fibre (SCF) as a parametric mixer. Our all-fibre, cavity-free source combines the materials benefits of planar waveguide structures with the advantageous properties of fibre platforms to achieve a 30 nm bandwidth comb source containing 143 tones with <3 kHz linewidth, 12 dB flatness, and >30 dB OSNR over the entire spectral region. The unique combination of technical features offered by this SCF-based source opens a path towards a new class of high-performance frequency comb generators for communications and signal processing applications.

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

1970 ◽  
Vol 28 ◽  
pp. 360-361
Author(s):  
John W. Coleman
Keyword(s):  
Boundary Conditions ◽  
High Performance ◽  
Force Fields ◽  
Optical Design ◽  
Direct Conversion ◽  
Design Engineering ◽  
Design Data ◽  
Scalar Potentials ◽  
Geometric Elements ◽  
At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

Prospects for convergent beam electron diffraction with a 200kV cold field-emission transmission electron microscope

1991 ◽  
Vol 49 ◽  
pp. 466-467
Author(s):  
J W Steeds ◽  
R Vincent
Keyword(s):  
Field Emission ◽  
High Performance ◽  
Small Diameter ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Special Modification ◽  
Convergent Beam

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.

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