The potential for improving the penetration depth of optical coherence tomography systems by using light sources with longer wavelengths has been known since inception technique in early 1990s. Nevertheless, development mid-infrared long challenged maturity and fidelity components this spectral region, resulting slow acquisition, low sensitivity, poor axial resolution. In work, a spectral-domain system operating at central wavelength 4 µm an resolution 8.6 is demonstrated. produces...

Mid-infrared (MIR) imaging has emerged as a valuable tool to investigate biological samples, such tissue histological sections and cell cultures, by providing non-destructive chemical specificity without recourse labels. While feasibility studies have shown the capabilities of MIR approaches address key clinical questions, these techniques are still far from being deployable non-expert users. In this review, we discuss current state art technologies give an overview on technical innovations...

This paper provides an extensive survey of nonlinear parametric upconversion infrared (IR) imaging, from its origin to date. Upconversion imaging is a successful innovative technique for IR in terms sensitivity, speed, and noise performance. In this approach, the image frequency upconverted form visible/near-IR through three-wave mixing followed by detection using silicon-based detector or camera. 1968, Midwinter first demonstrated short-wave-IR (1.6 μm) visible (484 nm) wavelength bulk...

In this work we demonstrate, to the best of our knowledge, a novel wide field-of-view upconversion system, supporting monochromatic mid-infrared (mid-IR) images, e.g., for hyperspectral imaging (HSI).An optical parametric oscillator delivering 20 ps pulses tunable in 2.3-4 μm range acts as mid-IR illumination source.A standard CCD camera, synchronism with crystal rotation acquires only 2.5 ms upconverted images containing 64 kpixels, thereby eliminating need postprocessing.This approach is...

Abstract Quantum measurements using single-photon detectors are opening interesting new perspectives in diverse fields such as remote sensing, quantum cryptography and computing. A particularly demanding class of applications relies on the simultaneous detection correlated single photons. In visible near infrared wavelength ranges suitable do exist. However, low detector efficiency or excessive noise has hampered their mid-infrared (MIR) counterpart. Fast highly efficient thus sought after...

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...

In this Letter, we demonstrate efficient room temperature detection of ultra-broadband mid-wave-infrared (MWIR) light with an almost flat response over more than 1200 nm, exploiting nonlinear upconversion technique. Black-body radiation from a hot soldering iron rod is used as the IR test source. Placing 20 mm long periodically poled lithium niobate crystal in compact intra-cavity setup (>20 W CW pump at 1064 nm), MWIR wavelengths ranging 3.6 to 4.85 μm are upconverted near-infrared (NIR)...

We present a phenomenological one-parameter scaling equation of state that accurately represents osmotic pressures neutral flexible polymers in good solvents from the dilute through semidilute regime. The comprises sum scaled van't Hoff and des Cloizeaux terms including fitted parameter α, "crossover index", which encapsulates all chemical specificity determines relevant prefactors. Strikingly different values α are found for two very systems poly(ethyleneglycol)/water (PEG)...

Based on enhanced upconversion, we demonstrate a highly efficient method for converting full image from one part of the electromagnetic spectrum into new desired wavelength region.By illuminating metal transmission mask with 765 nm Gaussian beam to create an and subsequently focusing inside nonlinear PPKTP crystal located in high intra-cavity field 1342 solid-state Nd:YVO 4 laser, upconverted at 488 is generated.We have experimentally achieved upconversion efficiency 40% under CW...

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...

Mid-infrared hyperspectral imaging has in the past decade emerged as a promising tool for medical diagnostics. In this work, nonlinear frequency upconversion based 6 to 8 µm spectral range is presented first time, using both broadband globar and narrowband quantum cascade laser illumination. AgGaS2 used medium sum generation 1064 nm mixing laser. Angular scanning of crystal provides broad coverage at every spatial position image. This study demonstrates retrieval series monochromatic images...

We present highly efficient sum-frequency generation between two CW IR lasers using periodically poled KTP. The system is based on the 1064 and 1342 nm laser-lines of Nd:YVO4 lasers. This an all solid-state light source in yellow-orange spectral range. optimized terms efficiency as well stability. compare performance a singly doubly resonant system, find that stability superior to system. overall conversion single higher than for configuration.

In this Letter, hyperspectral imaging in the mid-IR spectral region is demonstrated based on nonlinear frequency upconversion and subsequent using a standard Si-based CCD camera. A series of upconverted images are acquired with different phase match conditions for conversion process. From this, sequence monochromatic 3.2-3.4 μm range generated. The imaged object consists United States Air Force resolution target combined polystyrene film, resulting presence both spatial information infrared image.

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 consider a technique for high-resolution image upconversion of thermal light. Experimentally, we demonstrate cw with resolution more than 200 × 1000 pixels thermally illuminated objects. This is the first demonstration (to our knowledge) upconversion. The method promises an alternative route to high-quantum-efficiency all-optical imaging in mid-IR wavelength region and beyond using standard CCD cameras. A particular advantage cameras compared state-of-the-art possibility tailor tune...

Upconversion of images is a generic method for shifting the spectral content entire images.A comprehensive theory upconversion incoherent light presented and compared against experiments.In particular we consider important case infinity corrected light.We show that spatial resolution better than corresponding coherent image case.The fundamental differences between are investigated theoretically experimentally.The includes general using TEM nm modes.

We investigate on the origins of infra-red stimulated luminescence (IRSL) signals in 3 potassium feldspars based IR-red spectroscopy (∼700–1050 nm) using a fiber-coupled tunable Ti:Sapphire laser, combination with different thermal and optical (pre)treatments samples. also measure dose-response curves wavelengths at stimulation temperatures so as to be able distinguish between traps their electron trapping cross-sections. Our data suggest that dosimetric signals, IRSL, post IR-IRSL...

We demonstrate a novel approach for high-resolution spectroscopy based on frequency upconversion and postfiltering by means of scanning Fabry-Perot interferometer. The system is sum-frequency mixing, shifting the spectral content from mid-infrared to near-visible region allowing direct detection with silicon-based CCD camera. This allows low noise even without cooling detector. A setup realized 3 μm regime resolution 0.2 nm using lithium niobate as nonlinear material mixing single-frequency...

Low noise detection with state-of-the-art mid-infrared (MIR) detectors (e.g., PbS, PbSe, InSb, HgCdTe) is a primary challenge owing to the intrinsic thermal background radiation of low bandgap detector material itself. However, researchers have employed frequency upconversion based (UCD), operable at room temperature, as promising alternative traditional direct schemes. UCD allows for use silicon-CCD/camera improve SNR. Using UCD, contributions from nonlinear itself should be evaluated in...

We present an experimental setup capable of time-resolved photoluminescence spectroscopy for photon energies in the range 0.51 to 0.56 eV with instrument time response 75 ps. The detection system is based on optical parametric three-wave mixing, operates at room temperature, has spectral resolving power, and shown be well suited investigating dynamical processes germanium-tin alloys. In particular, carrier lifetime a direct-bandgap <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...

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...

Mid-infrared (mid-IR) imaging and spectroscopic techniques have been rapidly evolving in recent years, primarily due to a multitude of applications within diverse fields such as biomedical imaging, chemical sensing, food quality inspection.Mid-IR upconversion detection is promising tool for exploiting some these applications.In this paper, various characteristics mid-IR the femtosecond regime are investigated using 4f setup.A fraction 100 fs, 80 MHz output from Ti:sapphire laser used...