Abstract:
Methods and apparatus (10, 20, 25, 60, 70) for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices (120) and controllers (224) to maintain or vary the polarization of modulated signals (212, 262) as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field (204, 254) and a probe beam (206, 252) upon an electro-crystal (202, 256) and detecting the modulation of the resulting probe beam (212, 262). Detection of the modulation of the probe beam (212, 262) is practiced by detecting and comparing the polarization components (216, 218, 266, 268) of the modulated probe beam (212, 262). Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus (10), modular optical devices (20, 25, 60, 70) for use with the apparatus, sample holders (400, 402, 500), and radiation source mounts (600, 650, 700) are also disclosed.
Abstract:
An ellipsometer or polarimeter system and method for controlling intensity of an electromagnetic beam over a spectrum of wavelengths by applying control (P2) and beam (P) polarizers, optionally in combination with an intervening and control compensator (C).
Abstract:
Die Erfindung betrifft ein Mikroskop zur Durchlichtuntersuchung von Objekten mit einem Strahlengang zwischen einer Beleuchtungsvorrichtung und einer Vorrichtung zur Betrachtung/Erfassung eines Objektbildes, insbesondere einer Kamera, bei dem im Strahlengang ein Interferometer angeordnet ist, welches Mittel zur Veränderung der Polarisation (4) und davon unabhängige Mittel zur Veränderung der relativen Phase (6) in wenigstens einem der Teilstrahlen (II) des Interferometers aufweist. Die Erfindung betrifft weiterhin ein Verfahren zur Durchlichtmikroskopie von Objekten (8, 9), bei dem der Strahlengang zwischen einer Beleuchtungsvorrichtung (1 ) und einer Vorrichtung (15) zur Betrachtung/Erfassung eines Objektbildes durch ein Interferometer (II, III) führt, wobei wenigstens ein Abbild eines Objektes (8, 9), insbesondere eine Serie von Abbildern mittels einer Kamera (15) aufgenommen wird, insbesondere in Abhängigkeit von einer Lage der Polarisation und/oder der Phase des Lichtes in wenigstens einem der Teilstrahlen (II, III) des Interferometers.
Abstract:
A variety of toy polariscopes are simpler in design and less costly than precision instruments used in scientific research and stress analysis of materials and structures. The toy polariscopes are designed for a variety of objects that may exhibit photoelastic properties such as glass, plastic, Plexiglas, gel candle material and other gels, and even edible photoelastic objects. They are specially designed for objects of various sizes with a variety of purposes such as objects to enhance learning in a variety of conditions and experiences. Special objects are designed to go with the toy polariscopes such as edible and inedible photoelastic objects, photoelastic candle material, a variety of photoelastic/ photoplastic stands capable of a variety of displays in interaction with other designed photoelastic objects capable of a variety of interaction and displays. Other optical phenomena may also be observed.
Abstract:
An Optical communications apparatus, comprising: (a) an optical integrated device comprising an input, one or more integrated optical component(s) and an output, arranged such that light received by the input is propagated by the optical component(s) and exits the device as an output light beam; (b) a light beam diverter arranged to divert a sample portion only of the power of the output light beam; (c) a light detector arranged to detect the sample portion of the output light beam; and (d) a polariser located between the light beam diverter and the light detector and/or between the output of the optical integrated device and the light beam diverter, the polariser being arranged such that if light of a predetermined polarisation is received by the optical integrated device, the polariser propagates light of that polarisation only, thereby substantially to prevent light other than of the predetermined polarisation being detected by the light detector.
Abstract:
The degree of polarization of an optical signal is measured by a polarimeter and used for providing a feedback signal to adjust adaptive optics of a polarization mode dispersion compensator. The polarization properties of the polarimeter are determined with high accuracy to match the polarimeter through calibration and used to produce the feedback signal.
Abstract:
An apparatus for making automated measurements of an optical property of a sample includes a first stage (36) which is movable along a predetermined line, a second stage (50) for holding the sample, as a third stage which is movable along a predetermined line, correspondingly to the motion of the first stage. A light source (18) is mounted on the first stage, and a light detector is mounted on the third stage. The second stage rotates the sample to a selected rotary position. The apparatus also includes a controller for coordinating movement of the first, second, and third stages such that the light source, the sample, and the light detector are optically aligned.
Abstract:
The surface of a doped semiconductor wafer (12) is heated locally by means (14) of a pump beam whose intensity is modulated at a first frequency (18). The heated area (12a) is sampled by a probe beam (42) whose intensity is modulated at a second frequency (46). After the probe beam (42) has been modulated (reflected or transmitted) at the first frequency by the wafer (12), the modulated probe beam (50) is detected at a frequency equal to the difference between the harmonics of the first and second frequencies to determine dose of the dopants in the wafer (12). Such or similar type of instrument for measuring dose may be combined with an ellipsometer (100), reflectometer or polarimeter for measuring dose as well as thickness(es) and/or indices of refraction in a combined instrument for measuring the same sample (12).
Abstract:
A video imaging device includes a light source (2), a detector (36), and an optical polarization system (6, 38) for video imaging of superfical biological tissue layers (26, 32). The device relies on taking a set of measurements at different polarization orientations so as to render a new image that is independent of the light (22) reflected from the surface (12) of a tissue sample (14) and that is independent of the light (34) scattered from deep tissue layers (32).