Direct detection of polystyrene equivalent nanoparticles with diameter of 21 nm (∼λ/19) using coherent Fourier scatterometry: erratum.

We present an erratum to our article Kolenov, D., et al. "Direct detection of polystyrene equivalent nanoparticles with a diameter of 21 nm ( ∼ λ/19) using coherent Fourier scatterometry." Opt. Express29, 16487 (2021)10.1364/OE.421145.

Direct detection of polystyrene equivalent nanoparticles with a diameter of 21 nm (∼λ/19) using coherent Fourier scatterometry.

Coherent Fourier scatterometry (CFS) has been introduced to fulfil the need for noninvasive and sensitive inspection of subwavelength nanoparticles in the far field. The technique is based on detecting the scattering of coherent light when it is focused on isolated nanoparticles. In the present work, we describe the results of an experimental study aimed at establishing the actual detection limits of the technique, namely the smallest particle that could be detected with our system. The assessment for particles with a diameter smaller than 40 nm is carried out using calibrated nano-pillars of photoresist on silicon wafers that have been fabricated with e-beam lithography. We demonstrate the detection of polystyrene equivalent nanoparticles of diameter of 21 nm with a signal-to-noise ratio of 4 dB using the illuminating wavelength of 405 nm.

Multicomponent gas analysis using broadband quantum cascade laser spectroscopy.

We present a broadband quantum cascade laser-based spectroscopic system covering the region between 850 and 1250 cm(-1). Its robust multipass cavity ensures a constant interaction length over the entire spectral region. The device enables the detection and identification of numerous molecules present in a complex gas mixture without any pre-treatment in two minutes. We demonstrate that we can detect sub-ppmv concentration of acetone in presence of 2% of water at the same wavenumber region.