30 results about "Mode scrambler" patented technology

Embodiments of the present invention provide an apparatus with a flexible probe suitable for determining properties of in vivo tissue from spectral information collected from various tissue sites. An illumination system provides light at a plurality of broadband ranges, which are communicated to a flexible optical probe. Light homogenizers and mode scramblers can be employed to improve the performance in some embodiments. The optical probe in some embodiments physically contacts the tissue, and in some embodiments does not physically contact the tissue. The optical probe receives light from the illumination system and transmits it to tissue, and receives light diffusely reflected in response to the broadband light, emitted from the in vivo tissue by fluorescence thereof in response to the broadband light, or a combination thereof. The optical probe can communicate the light to a spectrograph which produces a signal representative of the spectral properties of the light. An analysis system determines a property of the in vivo tissue from the spectral properties.

A surface wave plasma (SWP) source having an electromagnetic (EM) wave launcher configured to couple EM energy in a desired EM wave mode to a plasma by generating a surface wave on a plasma surface of the EM wave launcher adjacent the plasma. A power coupling system is coupled to the EM wave launcher, and configured to provide the EM energy to the EM wave launcher for forming the plasma. A mode scrambler coupled to the plasma surface of the EM wave launcher, and configured to reduce mode jumping between the desired EM wave mode and another EM wave mode.

A fiber optic mode scrambler includes a multi-mode optical fiber formed with a core and a cladding around the core and a non-adiabatic cross-sectional shape change zone in the optical fiber. The fiber further has a bending region extending over a length of the optical fiber. The optical fiber has a non-zero curvature at the bending region and a device for maintaining the curvature of the optical fiber at the bending region. Mode scramblers can be provided that are accurately adjusted to match with different desired optical characteristics. A well-controlled manufacturing method for the mode scrambler is also described.

The invention discloses a distributed optical fiber Brillouin sensor fused with an optical fiber Brillouin frequency shifter, which is a distributed optical fiber sensor manufactured through the frequency shift effect of Brillouin scattering of an optical fiber, an optical fiber broadband nonlinear optical amplification effect, the strain and temperature effects of Brillouin scattered light of coherent amplification, and an optical time domain analysis principle, and comprises a narrow linewidth single frequency optical fiber laser, three optical fiber branching devices, a pulse modulator, the optical fiber Brillouin frequency shifter, two optical fiber circulators, an erbium-doped optical fiber amplifier, a polarization mode scrambler, an optical fiber narrowband reflection filter, an optical fiber Raman pump laser, a single-mode sensing optical fiber, an optical fiber filter, a photoelectric reception amplifier module, two digital signal processors, a photoelectric heterodyne reception amplifier module and a computer, wherein the optical fiber Brillouin frequency shifter is formed by connecting the circulators, the single-mode optical fiber and the optical fiber Fabry-Perot (F-P) filter in turn. The sensor has a simple structure, low price and high measuring accuracy and stability.

The invention discloses a heterodyne balance detection system and detection method applied to the TDLAS direct absorption method under low signal-to-noise ratio. The modulation signal output by the DFB laser is divided into the detection light and the detection light by a 1×2 single-mode fiber beam splitter. The reference light and the probe light are severely attenuated by the environment to be tested. The single-mode fiber time delayer makes the two beams of light produce a phase difference, and the probe light also passes through the multimode noise scrambler to eliminate multimode noise, and forms heterodyne interference in the 2×2 multimode fiber splitter. The signal after heterodyne interference is split 1:1 and connected to a balanced detector to obtain an amplified interference signal with reduced detector noise. In the present invention, the reference light and the detection light are interfered in the 1×2 single-mode fiber beam splitter, and the output is equally divided by the 2×2 multi-mode fiber beam splitter, so that the direct current flow of the two output signals is stable regardless of whether the detection light fluctuates Similarly, access to a balanced detector can balance the anti-noise, which significantly improves the real-time and anti-noise capabilities.

The invention discloses an optical fiber mode stripper. The optical fiber mode stripper comprises an input end, an output end and an attenuation area. The input end comprises a first fiber core, a first inner cladding layer and a first outer cladding layer. The output end comprises a second fiber core, a second inner cladding layer and a second outer cladding layer. The attenuation area comprises a third fiber core and a third inner cladding layer. The third fiber core is connected between the first fiber core and the second fiber core, and the third inner cladding layer is connected between the first inner cladding layer and the second inner cladding layer and exposed between the first outer cladding layer and the second outer cladding layer. A plurality of grooves are formed in the third inner cladding layer and formed by extending along the circumferential direction of the third inner cladding layer. The invention further discloses a manufacturing method of the optical fiber mode stripper. The optical fiber mode stripper has the advantages that pump light output by an optical fiber laser device can be attenuated effectively, transmitting quality of the laser in an optical fiber is improved, output power of the optical fiber laser device is increased, and output quality of the optical fiber laser device is improved.