An arrangement for providing visual effects including light emitting members attached to a target, an imaging unit for locating the light emitting members, a computing unit for receiving real-time location information data from the imaging unit and controlling a laser projector based on the received location information data, a laser projector projecting a laser beam responsive to control information provided by the computing unit, and a partially reflecting mirror reflecting the projected laser beam with respect to the light emitting members towards and/or in the vicinity of the light emitting members and passing the light from the light emitting members to the imaging unit. Related method is presented.

The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: launching a reference pulse of light with a wavelength λ.sub.t from a light source into said optical component, collecting light signal output by said optical component into a Mode Group Separating optical fiber; detecting light signal output by said Mode Group Separating optical fiber. The Mode Group Separating optical fiber is a multimode fiber with an α-profile graded index core with an α-value chosen such that said fiber satisfies the following criterion at the wavelength λ.sub.t: $\frac{.Math.\mathrm{\Delta \tau }.Math..L}{\Delta T_{\mathrm{REF}}}>4$
where: Δτ is a time delay difference between consecutive mode groups; L is a length of said fiber; ΔT.sub.REF is a Full Width at Quarter Maximum of said reference pulse.

A spectropolarimetric apparatus according to an embodiment of the present invention includes a light source attachment/detachment unit to which a light source is detachably coupled, a polarization interferometer configured to split light emitted from the light source coupled to the light source attachment/detachment unit into a plurality of polarized light beams using a polarization beam splitter and irradiate at least some of the split polarized light beams to a reflective sample to output the reflected light, and a spectrometer configured to measure physical properties of the reflective sample by analyzing the output light, wherein a wavelength of the light source coupled to the light source attachment/detachment unit varies depending on the reflective sample.

A laser interferometer includes a light source configured to emit first laser light, an optical modulator including a vibrator and configured to modulate, by the vibrator, the first laser light into second laser light having a different frequency, an optical path switching unit disposed in a first optical path through which the first laser light travels and configured to switch a direction of travel of the first laser light between the first optical path and a second optical path different from the first optical path, a reflector including a light-reflecting surface configured to move along the second optical path and reflect the first laser light traveling through the second optical path, and a photoreceptor configured to receive first interference light of the second laser light and third laser light generated by reflection of the first laser light on an object to be measured, and second interference light of the second laser light and fourth laser light generated by reflection of the first laser light on the light-reflecting surface and output a light-receiving signal.

Disclosed is an acoustic resonance spectrometry system for analysing a sample, which includes an optical pump-probe device adapted to generate a pump beam and a probe beam, the pump beam being consisted of a series of ultra-short pump light pulses having a repetition frequency in the spectral domain of the gigahertz, the pump beam being directed towards an optoacoustic transducer to generate a periodic grating of coherent acoustic phonons in the sample, the probe beam being directed towards the sample to form a scattering beam of the probe beam on the grating of phonons, a frequency variation device being adapted to vary the repetition frequency of the pump beam in a spectral range and a photo-detection system configured to measure a scattering signal as a function of the repetition frequency in the spectral range.

The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: launching a reference pulse of light with a wavelength .sub.t from a light source into said optical component, collecting light signal output by said optical component into a Mode Group Separating optical fiber; detecting light signal output by said Mode Group Separating optical fiber.

The Mode Group Separating optical fiber is a multimode fiber with an -profile graded index core with an -value chosen such that said fiber satisfies the following criterion at the wavelength .sub.t:

[00001]$\frac{.Math..Math..L}{.Math..Math.T_{\mathrm{REF}}}>4$

where: is a time delay difference between consecutive mode groups; L is a length of said fiber; T.sub.REF is a Full Width at Quarter Maximum of said reference pulse.

Disclosed is an acoustic resonance spectrometry system for analysing a sample, which includes an optical pump-probe device adapted to generate a pump beam and a probe beam, the pump beam being consisted of a series of ultra-short pump light pulses having a repetition frequency in the spectral domain of the gigahertz, the pump beam being directed towards an optoacoustic transducer to generate a periodic grating of coherent acoustic phonons in the sample, the probe beam being directed towards the sample to form a scattering beam of the probe beam on the grating of phonons, a frequency variation device being adapted to vary the repetition frequency of the pump beam in a spectral range and a photo-detection system configured to measure a scattering signal as a function of the repetition frequency in the spectral range.

The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: providing a Mode Group Separating optical fiber in an optical path between a light source and said optical component; launching reference pulses of light with a wavelength t from said light source through said Mode Group Separating optical fiber into said optical component at discrete intervals between a core center and a core radius of said fiber.
The Mode Group Separating optical fiber is a multimode fiber with an -profile graded index core with an -value chosen such that said fiber satisfies the following criterion at the wavelength t: $\frac{.Math..Math..Math.L}{T_{\mathrm{REF}}}>4$
where: is a time delay difference between consecutive mode groups; L is a length of said fiber; T.sub.REF is a Full Width at Quarter Maximum of said reference pulses.

A spectropolarimetric apparatus according to an embodiment of the present invention includes a light source attachment/detachment unit to which a light source is detachably coupled, a polarization interferometer configured to split light emitted from the light source coupled to the light source attachment/detachment unit into a plurality of polarized light beams using a polarization beam splitter and irradiate at least some of the split polarized light beams to a reflective sample to output the reflected light, and a spectrometer configured to measure physical properties of the reflective sample by analyzing the output light, wherein a wavelength of the light source coupled to the light source attachment/detachment unit varies depending on the reflective sample.

Techniques for controlling an optical system include accessing a measured value of a property of a particular pulse of a pulsed light beam emitted from the optical system, the property being related to an amount of coherence of the light beam; comparing the measured value of the property of the light beam to a target value of the property; determining whether to generate a control signal based on the comparison; and if a control signal is generated based on the comparison, adjusting the amount of coherence in the light beam by modifying an aspect of the optical system based on the control signal to reduce an amount of coherence of a pulse that is subsequent to the particular pulse.