Related papers: Cavity enhanced absorption spectroscopy in the mid…
Supercontinua are broadband spectra that are essential to optical spectroscopy, sensing, imaging, and metrology. They are generated from ultrashort laser pulses through nonlinear frequency conversion in fibers, bulk media, and…
Mid-infrared (mid-IR) spectroscopy offers unparalleled sensitivity for the detection of trace gases, solids and liquids, which is based on the existence of strong telltale vibrational bands in this part of the spectrum. It was shown more…
We report a broadband long-wave infrared Fourier transform spectrometer with sensitivity exceeding that of previously reported direct-detection implementations. The system combines dual-comb spectroscopy with electro-optic sampling,…
Mid-infrared frequency comb spectroscopy enables measurement of molecular at megahertz spectral resolution, sub-hertz frequency accuracy and microsecond acquisition speed. However, the widespread adoption of this technique has been hindered…
Optical spectroscopic sensors are powerful tools for analysing gas mixtures in industrial and scientific applications. Whilst highly sensitive spectrometers tend to have a large footprint, miniaturized optical devices usually lack…
Optical cavities provide high sensitivity to dispersion since their resonance frequencies depend on the index of refraction. We present a direct, broadband, and accurate measurement of the modes of a high finesse cavity using an optical…
Mid-infrared (MIR) spectral imaging enables precise target identification and analysis by capturing rich chemical fingerprints, which calls for high-sensitivity broadband MIR imagers at room temperature. Here, we devise and implement a…
We achieve a quantum-noise-limited absorption sensitivity of 1.7/times10$^{-12}$ cm$^{-1}$ per spectral element at 400 s of acquisition time with cavity-enhanced frequency comb spectroscopy, the highest demonstrated for a comb-based…
We report on a novel approach to cavity-ring-down spectroscopy with the sample gas in saturated-absorption regime. This technique allows to decouple and simultaneously retrieve empty-cavity background and absorption signal, by means of a…
We report on an air-spaced virtually imaged phased array (VIPA) spectrometer that resolves the modes of a mid-infrared frequency comb with a repetition rate of 250 MHz, without an optical filter cavity. With a record spectral resolution of…
There is an increasing demand for precise molecular spectroscopy, in particular in the mid-infrared fingerprint window that hosts a considerable number of vibrational signatures, whether it be for modeling our atmosphere, interpreting…
We report on the design of a highly-nonlinear specialty fiber as a mid-infrared light source at 4.3 {\mu}m. A meter length of the designed solid-core chalcogenide based index-guided microstructured optical fiber (MOF) with circular air…
Mid-infrared observations of Active Galactic Nuclei (AGN) are important for understanding of the physical conditions around the central accretion engines. Chandra and XMM-Newton X-ray observations of a 300 arcmin^2 region in the Extended…
III-V semiconductor mid-infrared photodetectors based on intersubband transitions hold a great potential for ultra-high-speed operation up to several hundreds of GHz. In this work we exploit a ~350nm-thick GaAs/Al0.2Ga0.8As…
A fully stabilized mid-infrared optical frequency comb spanning from 2.9 to 3.4 um is described. The comb is based on half-harmonic generation in a femtosecond optical parametric oscillator, which transfers the high phase coherence of a…
By independently engineering strain and composition, this work demonstrates and investigates direct band gap emission in the mid-infrared range from GeSn layers grown on silicon. We extend the room-temperature emission wavelength above ~4.0…
We describe methods using frequency combs and optical resonators for recording two-dimensional (2D) ultrafast spectroscopy signals with high sensitivity. By coupling multiple frequency combs to higher-order modes of one or more optical…
The laser spectroscopy is a fundamental approach for the realisation of traceable optical frequency standards. In the $1.55\,\mu$m wavelength band, widely used in telecommunications, the acetylene is the typical and the most widespread…
We present deep Ka-band ($\nu \approx 33$ GHz) observations of the CMB made with the extended Very Small Array (VSA). This configuration produces a naturally weighted synthesized FWHM beamwidth of $\sim 11$ arcmin which covers an…
Our ability to efficiently detect and generate far-infrared (i.e., terahertz) radiation is vital in areas spanning from biomedical imaging to interstellar spectroscopy. Despite decades of intense research, bridging the terahertz gap between…