Abstract:
A terahertz spectrometer includes an optical fiber and an emitter. The optical fiber is branched from a gain fiber constituting an ultra-short pulse oscillator. The emitter generates a terahertz wave from a pulse beam guided from the gain fiber through the optical fiber.
Abstract:
A broadband light source includes one or more laser diodes that are capable of generating a pump signal having a wavelength shorter than 2.5 microns, a pulse width of at least 100 picoseconds and a pump optical spectral width. The light source also includes one or more optical amplifiers that are coupled to the pump signal and are capable of amplifying the pump signal to a peak power of at least 500 W. The light source further includes a first fiber that is coupled to the one or more optical amplifiers. The first fiber including an anomalous group-velocity dispersion regime and a modulational instability mechanism that operates to modulate the pump signal. In one particular embodiment, the pump signal wavelength resides in the anomalous group-velocity dispersion regime of the first fiber and where different intensities in the pump signal can cause relative motion between different parts of the modulated pump signal produced through modulational instability in the first fiber. The light source also including a nonlinear element that is coupled to the first fiber that is capable of broadening the pump optical spectral width to at least 100 nm through a nonlinear effect in the nonlinear element.
Abstract:
Methods and apparatus for the active control of a wavelength-swept light source used to interrogate optical elements having characteristic wavelengths distributed across a wavelength range are provided.
Abstract:
A sensor device that uses a number of bragg grating (FBG) sensors and novel interrogation system with a ring cavity configuration for simultaneous time-division-multiplexex (TDM) and wavelength-division-multiplexed (WDM) interrogation of FBG sensors. The ring cavity includes an amplifier, and output coupler and an optical circulator. The coupler is connected to a wavelength measuring system and the optical circulator is connected to the FBG sensors. The FBG sensors can be in a number of groups. TDM interrogation is applied to each group of FBG sensors while WDM interrogation is applied to each FBG sensors within each group.
Abstract:
A broadband light source includes one or more laser diodes that are capable of generating a pump signal having a wavelength shorter than 2.5 microns, a pulse width of at least 100 picoseconds and a pump optical spectral width. The light source also includes one or more optical amplifiers that are coupled to the pump signal and are capable of amplifying the pump signal to a peak power of at least 500 W. The light source further includes a first fiber that is coupled to the one or more optical amplifiers. The first fiber including an anomalous group-velocity dispersion regime and a modulational instability mechanism that operates to modulate the pump signal. In one particular embodiment, the pump signal wavelength resides in the anomalous group-velocity dispersion regime of the first fiber and where different intensities in the pump signal can cause relative motion between different parts of the modulated pump signal produced through modulational instability in the first fiber. The light source also including a nonlinear element that is coupled to the first fiber that is capable of broadening the pump optical spectral width to at least 100 nm through a nonlinear effect in the nonlinear element.
Abstract:
L'invention concerne un dispositifoptique (20) d'excitation pour générer des processus Raman stimulés, ledit dispositif optique (20) étant destiné à recevoir le faisceau laser (11) d'une source laser (10) impulsionnel. Le dispositif optique (20) comporte un séparateur optique pour séparerle faisceau laser sur une première et une deuxième voie (210, 220). La première voie (210) comporte une première fibre optique (211) et un système de pré- dérive de fréquenceadapté pour appliquer une première dérive temporelle de fréquence.Le dispositifoptique (20) comprend en outre une deuxième fibre optique (233) agencée pour récupérer des premier et deuxième sous-faisceaux (21, 22) en sortie de la première et de la deuxième voie (210, 220) et pour leur appliquer une deuxième dérive temporelle de fréquence, la deuxième fibre optique (233) et le système de pré-dérive de fréquence étant configurés pour que le premier et le deuxième sous-faisceau (21, 22) présententune dérive en fréquenceidentique. L'invention concerne en outre un système de mesure et un procédé d'excitation.
Abstract:
The present invention relates to a method for producing narrow spectral linewidths more particularly by narrowing the full wave half maximum (FWHM) linewidth to a narrowed spectral linewidth. One of the advantages of the method of the present invention is to detect molecular bonding in analyte via contactless approach optical sensor. Another advantage of the present invention is that each LED has its own broader FWHM spectral linewidth and narrowing the linewidth to its unique and precise wavelength which contributes to more accurate observations and determination of analyte concentration.
Abstract:
The invention relates to a surface refractive index scanning system for characterization of a sample. The system comprises a grating device for holding or receiving the sample, the device comprising at least a first grating region having a first grating width along a transverse direction, and a second grating region having a second grating width in the transverse direction. The first grating region and the second grating region are adjacent in the transverse direction, wherein the first grating region has a grating period Λ 1 in a longitudinal direction, and the second grating region has a grating period Λ 2 in the longitudinal direction, where the longitudinal direction is orthogonal to the transverse direction. A grating period spacing ΔΛ = Λ 1 − Λ 2 is finite. Further, the first and second grating periods are chosen to provide optical resonances for light respectively in a first wavelength band and a second wavelength band, light is being emitted, transmitted, or reflected in an out-of-plane direction, wherein the first wavelength band and the second wavelength band are at least partially non-overlapping in wavelength. The system further comprises a light source for illuminating at least a part of the grating device with light at an illumination wavelength band. Additionally, the system comprises an imaging system for imaging the emitted, transmitted or reflected light from the grating device. The imaging system comprises an optical element, such as a cylindrical lens or a bended mirror, configured for focusing light in a transverse direction and for being invariant in an orthogonal transverse direction, the optical element being oriented such that the longitudinal direction of the grating device is oriented to coincide with the invariant direction of the optical element, and an imaging spectrometer comprising an entrance slit having a longitudinal direction oriented to coincide with the invariant direction of the optical element. The imaging spectrometer further comprises a 2-dimensional image sensor. The invention further relates to a method.
Abstract:
A high confinement nonlinear optical fiber is provided along with methods of parametric amplification for use thereof. The nonlinear optical fiber may include a plurality of concentric layers which are configured to provide different guiding regimes to low-frequency and high-frequency components through transverse geometry and refractive index profiling, thus reducing waveguide dispersion. The resulting optical fiber provides a parametric device with phase-matching in any spectral region of interest, such that a fiber optic parametric amplifier (FOPA) implementing the optical fiber can amplify in any spectral window of interest. A narrow-band FOPA configured to minimize phase mismatching is also provided for use with the optical fiber, and may be implemented as a light source or a monochromator.
Abstract:
The invention provides for a device comprising an apparatus comprising (a) a transmission grating capable of diffracting a photon beam into a diffracted photon output, and (b) an image detector capable of detecting the diffracted photon output. The device is useful for measuring the spatial profile and diffraction pattern of a photon beam, such as a vacuum ultraviolet (VUV) beam.