Research Development Corporation of Japan

Other

Tsutomu Ichimura

Fumio Inaba

Masahiro Toida

Toshiyuki Nagoshi

Toshiyuki Nogoshi

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.

Fourier transform spectroscope with quadrangular common path

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.

Method and apparatus for measuring spectral absorption in an opaque

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.

High sensitive multi-wavelength spectral analyzer

Heterodyne receptor system and arrangement for visualizing optical

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.

Growing community of inventors

Sendai, Japan

Tsutomu Ichimura