Abstract:
A compact, high sensitive, multi-wavelength spectral analyzer capable of simultaneously obtaining a spectral distribution of extremely weak radiation such as bioluminescence, chemiluminescence, extremely weak fluorescence caused by excitation light, Raman scattered light, etc. with an extremely high luminosity and without wavelength scanning. The spectral analyzer comprises a spectroscope and a high sensitive one- or two-dimensional photodetector. The spectroscope includes an entrance slit, a collimator lens of high luminosity disposed such that a focal point of the collimator lens is coincident with the entrance slit to convert light emerging therefrom into parallel rays, a reflection diffraction grating that diffracts the parallel rays from the collimator lens to produce spectra, and an imaging lens that focuses the parallel rays diffracted by the reflection diffraction grating on an image plane thereof to form a spectral image. The photodetector is disposed on the image plane of the imaging lens.
Abstract:
The present invention provides a receptor system in which laser light from a laser source is directed onto a sample, the transmitted light from which is photomixed by a half mirror with laser light different in frequency from laser light from a local oscillator source, and the photomixed light is received by a receptor element dividing a light propagating zone into a plurality of sub-zones, said receptor element having an exit end, at which a spatial zone, which is defined between different points and in which interference occurs, is limited within a spatially resolvable minimum unit, to form a Fraunhofer diffraction image, whereby the 0 order diffraction image of the Fraunhofer diffraction image is partly or wholly detected by a photodetector, or alternatively a diffraction image at most n times as large as the 0 order spectrum is detected by the photodetector. By extracting a beat component from the photomixed light in this manner, a transmission image can be separated from scattered components for detection. With light including too many scattered components such as that transmitted through the human body or the like, it is possible to obtain information relating to an absorber. This invention is thus applicable to optical computer tomography, etc.
Abstract:
A surface emission type semiconductor light-emitting device includes a base having a main surface, a current blocking layer formed on the base, and a semiconductor layer formed on the current blocking layer. A circular recess or hole having a side wall which is substantially perpendicular to the main surface is formed in the semiconductor layer as extending therethrough and partly into the base. An impurity is introduced into the semiconductor layer through the side wall and thus there is defined a cylindrical diffusion region around the recess. A p-n junction is defined at an outer boundary of the diffusion region and the p-n junction effectively defines a light-emitting activation region. An additional diffusion region may be formed in the semiconductor layer for narrowing a current path in the semiconductor layer. A second current blocking layer may be formed on top of the semiconductor layer. The semiconductor layer may have a multi-layer structure which may be constructed to provide a current confinement effect.
Abstract:
An apparatus for effecting spatial Fourier transform spectroscopic detection of light from a surface luminescent object with high sensitivity by use of a quadrangular common path interferometer. The apparatus includes an improvement which consists of an additional imaging optical system which converges a light beam from the specimen so as to enter the beam splitter. The additional imaging optical system is disposed so that an image position is substantially coincident with the position of the second of three mirrors in the apparatus.
Abstract:
A semiconductor light emitting device, such as a light emitting diode or laser, includes a substrate which is provided with a hole and a pn junction extending adjacent to and in parallel with the side wall of the hole. Thus, the side wall of the hole extends in a direction perpendicular to a main surface of the substrate. A pair of electrodes is provided such that current flows across the pn junction so that light emitted in a vertical direction which is perpendicular to the main surface of the substrate. The hole may be either a through hole or a bore hole. With the additional provision of a pair of resonators, there is provided a semiconductor laser.
Abstract:
In the method of and apparatus for measuring a spectral absorption in an opaque specimen, a scattering specimen is illuminated with highly directional light of variable wavelength from a specific direction, thereby removing scattered rays as much as possible, and thus detecting the intensity of only parallel rays of a component transmitted or reflected in a specific direction (i.e., rectilinear component rays) by use of a highly directional detecting system, for example, a heterodyne light-receiving system, Michelson light-receiving system, highly directional optical system, etc. It is therefore possible to measure spectral absorption characteristics of a scattering specimen with high accuracy without picking up scattered light in other undesired directions nor other noise light. In addition, the measurement of the control is exceedingly simplified in comparison to the conventional method and thus the measurement is extremely facilitated. Thus, the method and apparatus of the present invention are suitable for measuring spectral absorption of a component transmitted or reflected in a specific direction in not only sparse heterogeneous systems having spatial resolving power, for example, suspensions, organic tissues, etc., but also dense translucent objects.
Abstract:
A light propagation region is divided into a plurality of subregions, each subregion being limited within a minimum spatial resolution unit where an interference occurs between discrete points, and a 0-order diffraction pattern of a Fraunhofer diffraction image is detected If a convex lens and either a pinhole or an optical fiber which is disposed on a focal plane of the convex lens are employed and the diameter of the pinhole or the core diameter of the optical fiber is set to be not greater than the first dark ring of a Fraunhofer diffraction image produced by the convex lens, it is possible to take out the greater part of the energy of a plane wave component that enters the lens from a predetermined direction and remove other components from different directions, i.e., scattering component. If a plurality of optical systems of this type are bundled together, only a plane wave with a one- or two-dimensional intensity distribution can be taken out with high brightness and high resolving power. Since the scattering component attenuates and only an information light component carried by the plane wave can be detected, it is possible to obtain information about an absorber even when the scattering component is greater than the information light component as in the case of light transmitted by a human body. Thus, it is possible to obtain great advantages in application to optical CT or the like.
Abstract:
The present invention relates to a photo-counting Fourier spectroscopic apparatus which enables spectroscopic detection of extremely fine emission light seen in a living-body specimen or the like as bioluminescence, chemiluminescence, and fluoroescence from a living-body specimen. A light from a specimen which emits an extremely faint light is guided to an interferometer. A two-dimensional photon counter is used as an interference fringe detector. The two-dimensional photo counting device counts the number of incident photons to form an image. The obtained image is subjected to Fourier analysis to thereby obtain spectral information about the incident light. A double beam interferometer, a triangular common path interferometer, a Michelson interferometer and other interferometers are used.