Recent advancements of mid-infrared (MIR) supercontinuum light sources have opened up new possibilities in laser-based trace gas sensing.While the inherently support wide spectral coverage, detection broadband absorption signals with high speed and low cost is traditionally limited by MIR detector arrays.In this work, we demonstrate that limitation can be circumvented upconverting signal into near-infrared (NIR) region, where cost-effective silicon-based arrays utilized to measure...

Mid-infrared (MIR) spectroscopy is emerging as an attractive alternative to near-infrared or visible spectroscopy. MIR offers a unique possibility probe the fundamental absorption bands of large number gases well vibrational spectra complex molecules. In this paper we discuss non-collinear upconversion means for obtaining in 5–10 μm range with resolution better than 20 cm−1 over full interval using four discrete phase-match settings. A theoretical treatment given and two different...

We compare a nonlinear upconversion detector with conventional cryogenic InSb for the detection of coherent infrared light showing near-shot-noise-limited performance in system. The is limited by dark noise, which results 500 times lower signal-to-noise ratio. two detectors are compared degenerate four-wave mixing (DFWM) signal mid-infrared, and applied to measure trace-level acetylene gas flow at atmospheric pressure, probing its fundamental rovibrational transitions. In addition system...

We present a combination of convolutional neural network (CNN) framework and fast MIR (mid-infrared spectroscopy) for classifying different types dark plastic materials that are commonly found in mixed waste (MPW) streams. Dark challenges identification because the low signal-to-noise ratio. The proposed CNN architecture (which we call PlasticNet) can reach an overall classification accuracy 100% identify constituent multiplastic blend with accuracy. system collect spectral data at rate up...

For the first time an upconversion based detection scheme is demonstrated for lidar measurements of atmospheric CO2-concentrations, with a hard target at range 3 km and backscatter from ~450 m. The pulsed signals 1572 nm are upconverted to 635 nm, detected by photomultiplier tube, test how technology performs in long system. approach compared existing direct using near-IR detector respect signal-to-noise ratio quantum efficiency. It analyzed field-of-view receiver system, detection, depends...

We demonstrate a robust, compact, portable and efficient upconversion detector (UCD) for differential absorption lidar (DIAL) system designed range-resolved methane (CH4) atmospheric sensing. The UCD is built on an intracavity pump that mixes 1064 nm laser with the backscatter signal at 1646 in 25-mm long periodically poled lithium niobate crystal. upconverted 646 detected by photomultiplier tube (PMT). noise equivalent power around 127 fW/Hz1/2 outperforms conventional InGaAs based...

Abstract Mid‐infrared (MIR) spectroscopy, which has important applications in medicine, environmental monitoring, materials, and food science, is widely performed using Fourier transform infrared (FTIR) spectrometers as gold standard. Despite decades of development, FTIR systems are vulnerable to vibration have limited temporal resolution due reliance on mechanically scanned mirrors MIR direct detectors that a slower response than their near‐infrared counterparts. Using cryogenically cooled...

Upconversion from mid-infrared (MIR) to near-visible wavelengths using sum-frequency generation enables sensitive and low-noise MIR light detection near-visible-light detectors. spectroscopy is important for a wide spectrum of compound characterization applications but challenged by the thermal noise inherent in conventional detectors, giving low detectivity. In this Letter, we show an upconversion-based scheme with unprecedented combination large bandwidth short sampling time. Using LiNbO3...

Two dimensional mid-infrared upconversion imaging provides unique spectral and spatial information showing good potential for spectroscopy hyperspectral imaging. However, to extract or from the upconverted images an elaborate model is needed, which includes non-collinear interaction. We derive here a general theory providing far field of light when two arbitrary fields interact inside nonlinear crystal. Theoretical predictions are experimentally verified incoherent radiation subsequently...

We present a scheme to estimate the noise equivalent power (NEP) of frequency upconversion detectors (UCDs), detecting mid-infrared (MIR) light. The NEP UCD is combined contribution NEPs from process and photodetector, used for upconverted signal. 2-5-μm MIR range particularly investigated in this letter using bulk periodically poled lithium niobate-based CW-intracavity UCD. measured as 20 fW/√Hz at wavelength 3.39 μm. Here, we showed that limiting factor not (estimated 2.3 μm) but...

Due to advantages of low dark-count rate, reduced dead-time, and roomtemperature operation, single-photon upconversion detectors for the telecom band are gaining strong interest as an alternative other counters.In this work, we investigate spatial spectral distribution upconverted spontaneous parametric downconversion (USPDC) noise, which is typical dominant noise source in short-wavelength-pumped 1.5 µm -1.6 µm.Our detector relies on a bulk periodically poled lithium niobate (PPLN) crystal...

We demonstrate efficient upconversion of modulated infrared (IR) signals over a wide bandwidth (up to frequencies in excess 1 GHz) via cavity-enhanced sum-frequency generation (SFG) periodically poled LiNbO3. Intensity IR signal is produced by combining beams from two 1547 nm narrow-linewidth lasers fiber coupler while tuning their wavelength difference down 10 pm or less. The SFG crystal placed inside an Nd:YVO4 ring cavity that provides 1064 circulating pump powers up 150 W unidirectional...

A computer controlled tunable mid-IR light source, based on single resonant difference frequency generation (DFG), is experimentally investigated. The DFG process pumped by an external cavity tapered diode laser, over a spectral range of 30 nm. Grating feedback to the mode channel narrows spectrum and allows for tuning emitted in from 780 810 takes place intra-cavity high finesse 1064 nm solid state Nd:YVO4 laser cavity, using periodically poled LiNbO3 as nonlinear material. Based this new...

Quantum key distribution (QKD), the of quantum secured keys useful for data encryption, is expected to have a crucial impact in next decades. However, although notable achievements accomplished last twenty years, many practical and serious challenges are limiting full deployment this novel technology current telecommunication infrastructures. In particular, co-propagation signals high-speed traffic within same optical fiber, not completely resolved, due intrinsic noise caused by high...

We present a new background free method for in situ gas detection that combines degenerate four-wave mixing with an infra-red light detector based on parametric frequency upconversion of light. The system is demonstrated at mid infrared wavelengths low concentration measurements acetylene diluted N₂ flow ambient conditions. It the able to cover more than 100 nm scanning range and detect concentrations as 3 ppm R9e line. A major issue small signal scattered it showed how spatial...

For the first time wide-band mid-infrared (6-10 µm) frequency upconversion in a LiInS2 crystal is obtained using 1064 nm pump. The absorption spectrum of polystyrene characterized near-infrared grating and Si-CCD.

We report on a broadband multi-element THz imaging system based fiber-coupled, integrated photoconductive emitters and detectors. 32 detectors are arranged in planar array. Advanced image reconstruction algorithms employed to reconstruct an object the plane.

Summary form only given. With upconversion based mid-infrared reflection spectroscopy we have proved it possible to differentiate between several common types of black plastics. This allow for the possibility efficient sorting plastics in clean fractions, paving road both economically viable and ecologically sustainable recycling. The present choice sort scrap plastic, is near-infrared where significant spectral features are [1]. However, dark reflected signal signatures vanishes [2]....

We designed an upconversion detector (UCD) for 1575 nm operation. The signal-to-noise ratio of the UCD is investigated by considering dependence efficiency and upconverted spontaneous parametric down-conversion noise on pump power.

A tunable 1.9µm Tm:YLF laser was built for low noise infrared upconversion imaging and spectroscopy. Its properties are compared to that obtained using a 1064nm mixing laser, focusing on spontaneous parametric downconversion generated noise.

To maximize signal-to-noise ratio for upconversion of near-infrared light we show that the mixing intensity should be 3 GW/m2. With emphasis on noise contribution from random duty-cycle errors optimum design parameters is discussed.

The return signal of an integrated path differential absorption lidar for atmospheric CO2 measurements at 1572 nm was shifted to 635 by upconversion technology, detected a photomultiplier tube, and compared conventional InGaAs detector.