The invention is directed at a miniature grism system. The miniature grism system is a single compact device that comprises a grism with collimating and focusing optics. In an aspect, the grism includes at least one prism and a grating. In an aspect, the miniature grism system, and more specifically the grism, includes at least one prism which is placed on either side of the grating. The focusing optics and the collimating optics are found on opposite sides of the grism system, sandwiching the prism and grating of the grism. In an aspect, the miniature grism system is configured to be retained within a filter wheel. The miniature grism system is configured to be used with telescopes having a small focal ratio.

The invention is directed at a miniature grism system. The miniature grism system is a single compact device that comprises a grism with collimating and focusing optics. In an aspect, the grism includes at least one prism and a grating. In an aspect, the miniature grism system, and more specifically the grism, includes at least one prism which is placed on either side of the grating. The focusing optics and the collimating optics are found on opposite sides of the grism system, sandwiching the prism and grating of the grism. In an aspect, the miniature grism system is configured to be retained within a filter wheel. The miniature grism system is configured to be used with telescopes having a small focal ratio.

An optical probe has a connecting part, a carrier, multiple optical fibers, and a lens hood. The carrier is inserted in the connecting part. The carrier has two opposite ends and a channel. The channel extends to the two opposite ends of the carrier. The multiple optical fibers are inserted in the channel of the carrier. The lens hood is connected to the connecting part. The multiple optic fibers inserted inside the channel are able to cover various orientations of oscillations of polarized light, promote accuracy of inspection result, and save a lot of time from repeated measuring.

Provided is a Fourier transform spectroscopy method that removes restrictions on spectral resolution and spectral accuracy in Fourier transform spectroscopy for observing a cyclic repeating phenomenon, that realizes, theoretically, infinitesimal spectral resolution accuracy. After accurately and sufficiently stabilizing the repetition period of a phenomenon, a temporal waveform is acquired by making a repetition period and a time width for observing the temporal waveform of a phenomenon strictly conform, and by performing a Fourier transform, acquired is a discrete separation spectrum in which the inverse number of the observation time window size T is made a frequency data gap. Measurement is repeated while causing the repetition period to change, and the gap of the discrete separation spectrum is supplemented. Thereby, in a case of an observation target in which the existence time of a phenomenon is longer than the repetition period, the spectral resolution of the obtained discrete separation spectrum becomes infinitesimal.