In this paper, a multiheterodyne architecture for molecular dispersion spectroscopy based on coherent dual-comb source generated using single continuous wave laser and electro-optic modulators is presented validated. The phase-sensitive scheme greatly simplifies previous implementations by the use of an dual comb phase-locking all signal generators setup eliminating, in way, necessity any reference optical path currently mandatory absorption-based instruments. immune to classical baseline...

Optical frequency combs (OFCs) generated through the modulation of continuous-wave lasers offer higher power per component, simple comb spacing control, and lower complexity cost than traditional OFCs. By these reasons, they are an interesting optical source for spectrometers. In this letter, a dual-comb architecture based on two OFCs from same laser using phase modulators is presented. The system features new placement spectroscopic sample that increases versatility, robustness, stability...

Even though dual-comb-based systems are employed almost routinely nowadays in an ever-increasing number of applications, efficient combination this effective technique with imaging arrangement, which would undoubtedly revolutionize hyperspectral imaging, had not yet been demonstrated. Here we present, to our knowledge, the first dual-comb system interferograms directly detected by a video camera. The system, based on scheme capable consistently generating at rate 1 Hz and below, combines...

In this paper, a technique for molecular dispersion spectroscopy based on heterodyne phase-sensitive detection is presented.The method offers immunity to fluctuations of the received optical power and an output linearly dependent gas concentration.Besides this, analytical model propagation light in gaseous samples has been developed enabling calibration-free operation.The proposed architecture tested experimentally validated using methane as target gas.

In this paper, a new approach to dual comb generation based on well-known optical techniques (Gain-Switching and Optical Injection Locking) is presented. The architecture can be implemented using virtually every kind of continuous-wave semiconductor laser source (DFB, VCSEL, QCL) without the necessity electro-optic modulators. This way, frequency-agile adaptive dual-comb provided with potential implementation capabilities from mid-infrared near ultraviolet. With RF comprising around 70...

Molecular dispersion spectroscopy encompasses a group of spectroscopic techniques for gas analysis that retrieve the characteristics sample from measurement profile its refractive index in vicinity molecular resonances. This approach, which is clear contrast to traditional methods based on detection absorption, provides inherent immunity power fluctuations, calibration-free operation, and an output linearly dependent concentration. Heterodyne phase-sensitive (HPSDS) very recently proposed...

Abstract A single‐layer, all‐dielectric metasurface exhibiting a strong toroidal resonance in the low‐atmospheric loss radio window of subterahertz W‐band is theoretically proposed and experimentally demonstrated. The fabricated on high‐resistivity floating‐zone silicon wafer by means single‐process, wet anisotropic etching technique. properties mode both constituent dielectric elements are rigorously investigated multipole decomposition technique full‐wave simulations. experimental...

A quantum cascade laser-based sensor for ambient air monitoring is presented and five gases, affecting the quality, can be quantified. The light sources are selected to measure CO, NO, NO2, N2O SO2. footprint of measurement setup designed fit in two standard 19" rack (48 cm × 65 cm) with 4 height units (18 whereas one holding optical components other contains electronics data processing unit. concentrations individual analytes measured using 2f-Wavelength Modulation Spectroscopy (2f-WMS) a...

Abstract In this paper, a terahertz hyperspectral imaging architecture based on an electro-optic dual-comb source is presented and demonstrated. contrast to single frequency sources, multi-heterodyne system allows for the characterization of whole spectral response sample in parallel all points along range system. This hence provides rapid, highly consistent results minimizes measurement artifacts. The illumination signal can be tailored (in coverage resolution) with high flexibility meet...

Electro-optic dual-comb spectrometers have proved to be a promising technology for sensitive, high-resolution and rapid spectral measurements.Electro-optic combs possess very attractive features like simplicity, reliability, bright optical teeth, typically moderate but quickly tunable spans.Furthermore, in arrangement, narrowband electro-optic are generated with level of mutual coherence that is sufficiently high enable multiheterodyning without inter-comb stabilization or signal processing...

An absolute-frequency terahertz (THz) dual-frequency comb spectrometer based on electro-optic modulators for tunable, high-resolution, and real-time rapid acquisition is presented. optical line of a master frequency (filtered via injection locking) serves as the seed to electro-optically generate pair new combs (probe local oscillator). Photomixing both with another coherent from same original generates narrow linewidth THz dual-comb teeth frequencies that can be referenced radio-frequency...

In this Letter, we present and experimentally validate the first direct hyperspectral dual-comb gas imaging system operating in mid-infrared region. This method provides an unmatched combination of super-fine spectral characterization high temporal resolution without need for thermal contrast between target molecules background. a proof-of-concept experiment, has allowed us to perform precision butane 3.4 µm band with time 1 s.

There is currently a major global interest in the monitoring of greenhouse gases (GHGs), recognized as main cause warming. At present, most widely accepted and utilized technique for accurate measurements GHGs atmosphere Fourier Transform Infrared (FTIR) analysis [1]. These systems are used ground-based networks, because they provide high accuracy concentration many trace simultaneously. However, disadvantage this type systems, besides cost, its size, which makes it difficult to use...

Abstract Chronic or sustained hyperglycemia associated to diabetes mellitus leads many medical complications, thus, it is necessary track the evolution of patients for providing adequate management disease that required restoration carbohydrate metabolism a normal state. In this paper, novel monitoring approach based on mm-wave spectroscopy comprehensively described and experimentally validated using living animal models as target. The measurement method has proved possibility non-invasive,...

Crowded with the fundamental signatures of many popular molecules, mid-infrared range electromagnetic spectrum is particularly attractive for applications ranging from identification transient phenomena to sensing trace gases. Dual-comb spectroscopy a technique that unveils potential access this region pair phase-locked optical frequency combs on high-resolution, real-time basis without mechanical limitations traditional spectrometers. As ideal characteristics an comb are strongly influenced...

Dispersion-based spectroscopic techniques present many desirable features when compared with classical absorption spectroscopy implementations, such as the normalization-free operation and extended dynamic range. In this Letter, we a new sensor design based on direct optical processing for heterodyne conversion in tunable laser chirped dispersion that allows implementations using low-speed photodetectors low-cost FM demodulators. The performance of setup has been validated target...

In this work, the generation of dual optical frequency combs based on gain-switching and injection locking is experimentally examined. The study reveals that an effective process can lead to optimized RF in terms span signal-to-noise ratio. system also minimizes overlap lines reduces number components involved, eliminating need for any external modulator (electro-optic, acousto-optic). validation was performed as a dual-comb spectrometer, which allowed determination absorption dispersion...

A novel method is proposed for improving the performance of traditional laser heterodyne radiometry. The technique, which based on use a wavelength modulated local oscillator laser, provides baseline-free spectra, lower limits detection, and better precision consistency than conventional approach. This tool could, therefore, boost accuracy current terrestrial planetary atmospheric studies.

We investigate the high frequency modulation characteristics of mid-infrared surface-emitting ring and edge-emitting ridge quantum cascade lasers (QCLs).In particular, a detailed comparison between circular devices ridge-QCLs from same laser material, which have linear waveguide in "Fabry-Pérot (FP) type" cavity, reveals distinct similarities differences.Both device types are single-mode emitting, based on either 2 nd -(ring-QCL) or 1 st -order (ridge-QCL) distributed feedback (DFB) gratings...

Vertical cavity surface emitting lasers fabricated with movable microelectromechanical mirrors can offer continuous single-mode wavelength tuning up to 100 nm high efficiency and in a very small package. Wide tunability makes these diode ideally suited for multispecies high-density gas analysis the first demonstrations of direct absorption spectroscopy modulation have already been published. The performance systems could nevertheless be enhanced by use new molecular dispersion spectroscopic...