Systems and methods of performing a stress measurement of a chemically strengthened glass using a light-scattering polarimetry system include adjusting the intensity of a light beam from a light source in an illumination system using a rotatable half-wave plate and a first polarizer operably disposed between the light source and a rotating light diffuser that has a rotation time t.sub.R. The first polarizer is aligned with a second polarizer in a downstream optical compensator to have matching polarization directions by rotating the rotatable half-wave plate to a position where the exposure time t.sub.E falls within an exposure range t.sub.Rt.sub.E. The method also includes performing an exposure using the exposure time t.sub.E to obtain the stress measurement. One or both of the half-wave plate and first polarizer can be tilted to avoid deleterious back-reflected light from entering the light source.

Systems and methods of performing a stress measurement of a chemically strengthened glass using a light-scattering polarimetry system include adjusting the intensity of a light beam from a light source in an illumination system using a rotatable half-wave plate and a first polarizer operably disposed between the light source and a rotating light diffuser that has a rotation time t.sub.R. The first polarizer is aligned with a second polarizer in a downstream optical compensator to have matching polarization directions by rotating the rotatable half-wave plate to a position where the exposure time t.sub.E falls within an exposure range t.sub.Rt.sub.E. The method also includes performing an exposure using the exposure time t.sub.E to obtain the stress measurement. One or both of the half-wave plate and first polarizer can be tilted to avoid deleterious back-reflected light from entering the light source.

A photoconductive switch for generating or detecting terahertz radiation (TR) is provided. The photoconductive switch may comprise at least a first and a second pair of electrodes (E.sub.V, E.sub.H, E.sub.GR) on a surface (SS) of a photoconductive substrate, wherein the electrodes of the first pair are separated by a first gap comprising at least a plurality of first rectilinear sections (G.sub.V) extending along a first direction (x) and the electrodes of the second pairs are separated by a second gap comprising at least a plurality of second sections (G.sub.H) extending along a second direction (y), different from the first direction. The photoconductive switch may further comprise a patterned opaque layer (PML) selectively masking portions of the gaps between the electrodes. Methods and devices for generating and detecting terahertz radiation comprising such photoconductive switches are also provided.

A device for determining a polarization state of an electromagnetic wave includes a power splitter that splits an electromagnetic input wave into at least three partial waves; and at least three polarization converters for changing the polarization state of the partial waves. One of the polarization converters is associated with one of the three partial waves. The device includes an output coupler to which the partial waves are supplied after passing through the respective polarization converter and which includes at least three outputs. The output coupler is configured and the polarization converters are arranged and configured such that output waves exiting from the outputs of the output coupler have an intensity that each is dependent on one of the Stokes parameters of the input wave.

Provided herein are systems and methods for monitoring radial stresses in glass tubing. In some embodiments, a measurement system includes a light source delivering a light to a tube, and a polarizer receiving the light after the light is refracted through a wall of the tube. The measurement system may further include a detector receiving the light from the polarizer, the detector operable to capture a first image of the light at a first polarization state and a second image of the light at a second polarization state. The system may further include a controller operable to determine a retardation profile related to the stress profile of the wall of the tube by determining a retardation magnitude of the light refracted through the wall of the tube based on a difference between the first image of the light and the second image of the light.

Provided herein are systems and methods for monitoring radial stresses in glass tubing. In some embodiments, a measurement system includes a light source delivering a light to a tube, and a polarizer receiving the light after the light is refracted through a wall of the tube. The measurement system may further include a detector receiving the light from the polarizer, the detector operable to capture a first image of the light at a first polarization state and a second image of the light at a second polarization state. The system may further include a controller operable to determine a retardation profile related to the stress profile of the wall of the tube by determining a retardation magnitude of the light refracted through the wall of the tube based on a difference between the first image of the light and the second image of the light.

A light source system is provided. The light source system is capable of measuring a polarization angle and includes a light source configured to emit an original light beam, and the original light beam has an original polarization angle. The light source system further includes an amplifying module configured to amplify the original light beam and generate a forward beam for hitting a target, and the forward beam has a forward polarization angle that is equal to the original polarization angle. The light source system further includes a polarization measurement unit, and the polarization measurement unit includes a first polarization measurement module configured to receive a first return beam and measure a first polarization angle of the first return beam. The first return beam is reflected from the target.

A sensing apparatus for detecting at least one target molecule in a gaseous medium is provided, comprising an optical fiber having a core with a tilted grating, and a coating assembly. The coating assembly has a composite film layer having an outer surface in direct contact with the gaseous medium, and contains at least two compositions mixed with one another therein, which include one or more surface plasmon resonance (SPR)-active compositions and one or more reacting compositions that are reversibly reactive to the at least one target molecule. Depending on different reacting compositions, the sensing apparatus can detect various target gas molecules such as hydrogen, ammonia, methane, and formaldehyde, etc. The sensing apparatus has relatively fast response time and high resistance to deactivation. A sensing system based on the sensing apparatus, a manufacturing method of the sensing apparatus, and a detection method using the sensing system, are further provided.

There is disclosed a system and method for measuring the polarization of light which utilizes a spatially-varying polarization beam. This measurement is analyzed and improved using novel imaging methods and image processing methods on a digital signal processing (DSP) system to determine the polarization of light. Various embodiments are described which can measure light polarization, determine polarizing material distributions, determine the optical rotary dispersion of samples, and determine the circular dichroism of samples. In certain embodiments, the binding constants and binding activity of molecular samples can be achieved. Given its reduced complexity and size, the system may be configured to be portable such that the system may be used in various applications outside of a lab setting.

An optical line device for use in an optical line system is configured to connect to a second optical line device via a transmit fiber and a receive fiber. The optical line device includes a transmitter connected to the transmit fiber via an output port of the optical line device, wherein the transmitter is configured to transmit a polarization probe signal at a wavelength outside of a band of wavelengths used for traffic-bearing channels in the optical line signal, to a second polarimeter receiver at the second optical line device; and a polarimeter receiver connected to the receive fiber via an input port of the optical line device, wherein the polarimeter receiver is configured to receive a second polarization probe signal from a second transmitter transmitted from the second optical line device and to derive a measurement of SOP on the receive fiber based on the second polarization probe signal.