Method and apparatus for measuring spectral absorption in an opaque specimen and method and apparatus for measuring the microscopic absorption distribution

An apparatus for measuring a microscopic absorption distribution in an opaque specimen, comprising:

• a monochromatic light source capable of varying the wavelength of light emitted therefrom;
• means for dividing the light from said light source into two light beams;
• means for shifting the frequency of incident light, said shift means being provided in the optical path of one of said two light beams;
• a confocal optical system comprising two convergent optical systems, said confocal optical system being disposed in the other optical path;
• a specimen disposed at a position where light is condensed by said confocal optical system, said specimen being capable of being scanned relative to said confocal optical system;
• means for combining together highly directional light emerging from said frequency shift means and light diverging from a measuring point on said specimen and converted into parallel rays by said confocal optical system and projecting the resulting composite light in the same direction;
• and
• means for converting the composite light from said beam combining means into an electric signal and detecting the intensity of only an AC component which is equal to the shifted frequency.

An apparatus for measuring a microscopic absorption distribution in an opaque specimen, comprising:

• a monochromatic light source capable of varying the wavelength of light emitted therefrom;
• means for dividing the light from said light source into two light beams;
• means for changing the optical path length at a predetermined speed, said optical path length changing means being provided in the optical path of one of said two light beams;
• a confocal optical system comprising two convergent optical systems, said confocal optical system being disposed in the other optical path;
• a specimen disposed at a position where light is condensed by said confocal optical system, said specimen being capable of being scanned relative to said confocal optical system;
• means for combining together highly directional light emerging from said optical path length changing means and light diverging from a measuring point on said specimen and converted into parallel rays by said confocal optical system and projecting the resulting composite light in the same direction;
• and
• means for converting the composite light from said beam combining means into an electric signal and detecting the intensity of only an AC component of a frequency corresponding to the optical path length changing speed.

An apparatus for measuring a microscopic absorption distribution in an opaque specimen, comprising:

• a monochromatic light source capable of varying the wavelength of light emitted therefrom;
• means for dividing the light from said light source into two light beams;
• means for shifting the frequency of incident light, said shift means being provided in the optical path of one of said two light beams;
• a first convergent optical system disposed in the other optical path to illuminate a very small measuring point on a specimen with condensed light of high directivity;
• a specimen disposed at a position where light is condensed by said first convergent optical system, said specimen being capable of being scanned relative to said first convergent optical system;
• a second convergent optical system arranged to illuminate said specimen with highly directional light emerging from said frequency shift means in the form of the same convergent spherical wave as that obtained from said first convergent optical system;
• means for combining together light emerging from said frequency shift means and light diverging from the measuring point on said specimen and converted into parallel rays by said second convergent optical system and projecting the resulting composite light in the same direction;
• and
• means for converting the composite light from said beam combining means into an electric signal and detecting the intensity of only an AC component which is equal to the shifted frequency.