Abstract:
A spectrophotometer system adapted to be inserted into the side of a compact computer or other computerized devices, as an accessory card which may interface with the computer in accordance with the standards of the Personal Computer Memory Card International Association (PCMCIA) is provided. On this card and disposed along an edge thereof is a spectrophotometer (24). The spectrophotometer optics (26) are connected to a fiber optic cable (32) at the end of which is a light receiving and transmitting opening exposed to the object under test. The card may carry a lamp (36) which is coupled to the fiber optic from the spectrophotometer so as to illuminate the object under test. The card has all of the electronics necessary for spectral measurements, including a microprocessor.
Abstract:
An apparatus and method for in situ spectral measurement is disclosed. The apparatus uses a low-resolution grating to disperse light and thereby image a spectrum thereof. The imaged spectrum is converted into a digital electrical signal and is processed in order to enhance the spectral information. The resulting spectral information is analogous to that captured using a higher resolution spectral imager with optical processing of the spectral data.
Abstract:
The present invention concerns a procedure for controlling a radiation source which has been implemented with the aid of light-emitting diodes, or LEDs, from the radiation produced by them being separated the desired wavelength range, of which the intensity is controlled or maintained constant. The radiation source is implemented by means of a LED row (2) formed of semiconductor chips, or LED elements, (21, 22, 23,..., 26), from the radiation of which is separated a wavelength range (DELTAlambda1, DELTAlambda2,...) depending on the location of the LED element in said arrays with an optical means dispersing the radiation to a spectrum, and the intensity of the radiation in this wavelength range, or of the output radiation, is controlled or maintained constant by observing the intensity thereof and regulating with its aid the current passing through the respective LED element. The wavelength ranges of the output radiation are selected electrically by activating a suitable LED element (21, 22, 23,..., 26) in the LED row (2).
Abstract:
A spectrograph usable as a demutiplexer/detector in a wavelength division multiplexing optical system. The spectrograph comprises a planar waveguide (50) and a detector array (52). The planar waveguide (50) has a dispersive edge (56) having an inwardly concave shape, an input edge (62), and a straight output edge (64). The dispersive edge (56) has a reflective diffraction grating (60) formed on it, the grating (60) having a variable line spacing. An optical input signal comprising a plurality of different wavelength ranges enters the waveguide at the input edge (62), and travels through the waveguide and strikes the grating (60). The grating (60) focuses the optical energy in each of the wavelength ranges at a focal spot at the output edge (64), the position of each focal spot being a function of wavelength. The detector array (52) comprises a plurality of photodetectors positioned along a straight line, such that the photodetectors are positioned at the focal spots. Each photodetector therefore detects the optical energy in one of the input ranges. A stack of such planar waveguides may be assembled to form a multi-channel spectrograph.
Abstract:
Un analyseur spectral optique permet de recevoir un faisceau d'entrée (30) par l'intermédiaire d'une fibre optique multimode (28). Le faisceau d'entrée (30) présente une largeur de bande spectrale prédéterminée. Les composantes spectrales individuelles aléatoires du faisceau (30) sont dispersées par une grille (40) afin de générer un spectre (42, 42'...42N). Un détecteur (52) détecte l'ordre de grandeur des éléments dans un spectre focalisé réfléchi (50, 50'...50N) en vue de recueillir les informations placées par un dispositif d'encodage de spectre sur la fibre optique (28) à un endroit éloigné.
Abstract:
In the spectroscopy module 1, a light absorbing layer 6 having a light-passing hole 6a through which light L1 advancing into a spectroscopic portion 3 passes and a light-passing hole 6b through which light L2 advancing into a light detecting portion 4a of a light detecting element 4 passes is integrally formed by patterning. Therefore, it is possible to prevent deviation of the relative positional relationship between the light-passing hole 6a and the light-passing hole 6b. Further, since the occurrence of stray light is suppressed by the light absorbing layer 6 and the stray light is absorbed, the light detecting portion 4a of the light detecting element 4 can be suppressed from being made incident. Therefore, according to the spectroscopy module 1, it is possible to improve the reliability.
Abstract:
A structure for guiding electromagnetic radiation, comprising: a substrate (230); a waveguide (220) provided on the substrate and having a first end (220a) for receiving electromagnetic radiation and a second end (220b); and an anti-reflection region (270) provided at the second end (220b) of the waveguide on the substrate, the length and the width of the anti-reflection region being optimised to suppress back reflection of radiation that reaches the second end.
Abstract:
A 2-D sensor array includes a semiconductor substrate and a plurality of pixels disposed on the semiconductor substrate. Each pixel includes a coupling region and a junction region, and a slab waveguide structure disposed on the semiconductor substrate and extending from the coupling region to the region. The slab waveguide includes a confinement layer disposed between a first cladding layer and a second cladding layer. The first cladding and the second cladding each have a refractive index that is lower than a refractive index of the confinement layer. Each pixel also includes a coupling structure disposed in the coupling region and within the slab waveguide. The coupling structure includes two materials having different indices of refraction arranged as a grating defined by a grating period. The junction region comprises a p-n junction in communication with electrical contacts for biasing and collection of carriers resulting from absorption of incident radiation.