Miniaturized confocal spectrometer

A confocal spectrometer, comprising:

• a first subassembly comprising an illuminating device having a light source emitting a beam having an elongate elliptical cross section;
• a second subassembly comprising a confocal arrangement of first, second, and third converging lenses in which:
• (i) the first converging lens receives the beam from the light source and provides an incident elliptical beam to an input of an illumination beam path, (ii) the second converging lens is disposed at an output of, and receives the incident elliptical beam from, the illuminating beam path such that the incident elliptical beam irradiates an object under test, (iii) a dichroic beam splitter receives responsive radiation from the object in response to the incident elliptical beam, wherein the responsive radiation from the object enters the second converging lens at an input of a detecting beam path, wherein the responsive radiation is received by the dichroic beam splitter and is deflected toward an output of the detecting beam path, and wherein the object is arranged substantially close to a common focal point of the illuminating beam path and the detecting beam path;
• and (iv) the third converging lens is located at the output of the detecting beam path and receives the responsive radiation therefrom;
• and
• a third subassembly comprising:
• (i) a microspectrometer having an entry slit receiving the responsive radiation from the third converging lens such that a large main axis of an elliptical beam of the responsive radiation runs parallel to a longitudinal axis of the entry slit, and (ii) a viewing device for providing a spectrum of the responsive radiation from the object,
• wherein the first, second, and third subassemblies are permanently set with respect to one another and are rigidly and durably joined together.