相关论文: Disordered, strongly scattering porous materials a…
Optical gas detection in microsystems is limited by the short micron scale optical path length available. Recently, the concept of slow-light enhanced absorption has been proposed as a route to compensate for the short path length in…
High-resolution spectroscopy in the near-infrared could become the leading method for discovering extra-solar planets around very low-mass stars and brown dwarfs. To help to achieve an accuracy of ~m/s, we are developing a gas cell which…
Dynamic light scattering techniques are routinely used for numerous industrial and research applications, because they can give access to the motion spectrum of micro- and nano-objects, and therefore to particle sizes or visco-elastic…
Non-invasive detection of objects embedded inside an optically scattering medium is essential for numerous applications in engineering and sciences. However, in most applications light at visible or near-infrared wavebands is scattered by…
We have carried out theoretical research on ultra-high resolution spectroscopy of atoms (or molecules) in the suggested cell with a series of plane-parallel thin gas layers between spatially separated gas regions of this cell for optical…
The multiple-pass optical cell is an important tool for laser absorption spectroscopy and its many applications. For most practical applications, such as trace-gas detection, a compact and robust design is essential. Here we report an…
We report multipass broadband photoacoustic spectroscopy of trace gases in the mid-infrared. The measurement principle of the sensor relies on supercontinuum-based Fourier transform photoacoustic spectroscopy (FT-PAS), in which a scanning…
High-resolution optical microscopy suffers from a low contrast in scattering media where a multiply scattered wave obscures a ballistic wave used for image formation. To extend the imaging depth, various gating operations - confocal,…
Molecules are emerging as new benchmark for metrology and fundamental physics research, driving the demand for spectroscopic techniques combining high sensitivity and resolution. Photoacoustic spectroscopy has proven to combine high…
Portable and cost-effective gas sensors are gaining demand for a number of environmental, biomedical and industrial applications, yet current devices are confined into specialized labs and cannot be extended to general use. Here, we…
The transmission of light through low coverage regular and random arrays of glass supported silica micropillars of diameters 10 to 40 \micro\meter and height 10 \micro\meter is studied experimentally. Angle-resolved measurements of the…
We show that high-resolution laser spectroscopy can probe surface interactions of gas confined in nano-cavities of porous materials. We report on strong line broadening and unfamiliar lineshapes due to tight confinement, as well as signal…
Considerable interest is now focused on the detection of terrestrial mass planets around M dwarfs, and radial velocity surveys with high-resolution spectrographs in the near infrared are expected to be able to discover such planets. We…
Label-free imaging of rapidly moving, sub-diffraction sized structures has important applications in both biology and material science, as it removes the limitations associated with fluorescence tagging. However, unlabeled nanoscale…
We propose the use of wavelength-dependent spectroscopic absorption in the evanescent field of ultra-compact whispering gallery mode microspherical lasers as selective gas sensors and estimate few ppm detection sensitivity using a simple…
Sensing and manipulating targets hidden under scattering media are universal problems that take place in applications ranging from deep-tissue optical imaging to laser surgery. A major issue in these applications is the shallow light…
We report on precision spectroscopy of sub-wavelength confined molecular gases. This was obtained by rovibrational selective reflection of $\mathrm{NH_3}$ and $\mathrm{SF_6}$ gases using a quantum cascade laser at $\lambda\approx 10.6 \mu…
Gaseous Optical Time Projection Chambers (OTPCs) aimed at Neutrino Physics and Rare Event Searches will likely exceed the tonne scale during the next decade. This will make their performance sensitive to gas contamination levels as low as…
Porous, atomically thin graphene membranes have interesting properties for filtration and sieving applications because they can accommodate small pore sizes, while maintaining high permeability. These membranes are therefore receiving much…
Small angle X-ray scattering (SAXS) was used to quantitatively study the morphology of aligned, mono-disperse conical etched ion tracks in thin films of amorphous silicon dioxide with aspect ratios of around 6:1, and in polycarbonate foils…