Abstract: A method to measure the refractive index of a sample, includes: providing a plasmonic sensor including a sensing surface in contact with the sample; providing an optical resonator, the plasmonic sensor being integrated therein as a reflecting surface; providing a first input field of electromagnetic radiation as a primary carrier; providing a second input field of electromagnetic radiation as a secondary carrier having a second frequency different from the first and defined as: second frequency=first frequency+?v and having a TE and/or a TM polarized component; impinging simultaneously with the first and second input field the plasmonic sensor; tuning the frequency of the first field and/or the value of ?v; detecting a resonator output power corresponding to the first and second intra-cavity fields resonating; determining a difference between the first and the second resonating frequencies; and calculating the refractive index of the sample from the difference.

Abstract: The present invention is relative to a method of ring-down spectroscopy in saturated-absorption condition, for measuring a first concentration of a gas through a measurement of the spectrum of a molecular transition of said gas.

Abstract: A method to measure the refractive index of a sample, includes: providing a plasmonic sensor including a sensing surface in contact with the sample; providing an optical resonator, the plasmonic sensor being integrated therein as a reflecting surface; providing a first input field of electromagnetic radiation as a primary carrier; providing a second input field of electromagnetic radiation as a secondary carrier having a second frequency different from the first and defined as: second frequency=first frequency+?v and having a TE and/or a TM polarized component; impinging simultaneously with the first and second input field the plasmonic sensor; tuning the frequency of the first field and/or the value of ?v; detecting a resonator output power corresponding to the first and second intra-cavity fields resonating; determining a difference between the first and the second resonating frequencies; and calculating the refractive index of the sample from the difference.

Abstract: The present invention relates to a ring-down spectrometry apparatus in absorption saturation condition, for measuring the concentration of a gas through a measurement of the spectrum of a molecular transition of said gas. The apparatus includes a laser source, an adjuster for varying the wavelength of said radiation emitted by said laser, and a resonant cavity. A photodetector is adapted to detect an electromagnetic radiation beam and is adapted to generate a decay signal. An electronic circuit receives the signal from the photodetector and is adapted to convert it to a processor. A processor is adapted to receive said decay signal from the photodetector and perform interpolation to obtain a concentration of said gas.

Abstract: The present invention is relative to a method of ring-down spectroscopy in saturated-absorption condition, for measuring a first concentration of a gas through a measurement of the spectrum of a molecular transition of said gas.

Abstract: Low-noise current source, configured to be supplied by at least one DC main supply (Vss) and to deliver an output current (IL), the source comprising one or more current generator modules (G1, G2, . . . GN) operating in parallel each one of which is configured to deliver a respective output current (Ii), whereby the output current (IL) of the source is equal to the sum of the output currents (Ii) of said one or more current generator modules (G1, G2, . . . GN), each current generator module (G1; G2; . . . GN) comprising a regulator component (Q1), configured to deliver the output current (Ii) of the current generator module (G1; G2; . . .

Abstract: Low-noise current source, configured to be supplied by at least one DC main supply (Vss) and to deliver an output current (IL), the source comprising one or more current generator modules (G1, G2, . . . GN) operating in parallel each one of which is configured to deliver a respective output current (Ii), whereby the output current (IL) of the source is equal to the sum of the output currents (Ii) of said one or more current generator modules (G1, G2, . . . GN), each current generator module (G1; G2; . . . GN) comprising a regulator component (Q1), configured to deliver the output current (Ii) of the current generator module (G1; G2; . . .

Abstract: The present invention relates to a method and an apparatus to perform frequency comb spectroscopy.

Abstract: The present invention relates to a ring-down spectrometry apparatus in absorption saturation condition, for measuring the concentration of a gas through a measurement of the spectrum of a molecular transition of said gas. The apparatus includes a laser source, an adjuster for varying the wavelength of said radiation emitted by said laser, and a resonant cavity. A photodetector is adapted to detect an electromagnetic radiation beam and is adapted to generate a decay signal. An electronic circuit receives the signal from the photodetector and is adapted to convert it to a processor. A processor is adapted to receive said decay signal from the photodetector and perform interpolation to obtain a concentration of said gas.

Abstract: The present invention relates to a method and an apparatus to perform frequency comb spectroscopy.

Abstract: A method for measuring and two-dimensional mapping of electro-optical properties of materials using a Reflective Grating Interferometer (RGI) includes projecting a substantially coherent and monochromatic electromagnetic beam subjected to a homogeneous electrical field so the beam is enlarged to have a two-dimensional cross section comparable with dimensions of the material, dividing the electromagnetic beam into one part that crosses the material and another part that travels undisturbed, recomposing the two beams on a recombination element of the RGI, detecting the recombined beam by a device suited to two-dimensional detection of such beam. The method also includes: E. obtaining phase variation ?ø(x,y) between the divided beams; F. varying the applied electrical field value and repeating the detection steps; G.