JPS5929804B2 - spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spectrometer that disperses radiation from a light source into a spectrum and extracts monochromatic light of a desired wavelength.
In particular, it relates to a spectrometer using a concave diffraction grating as a dispersive element.

In the field of measurement, spectroscopic analysis is currently being widely used.

Spectroscopic analysis refers to chemical analysis performed using the spectroscopic properties of substances that are found by measuring and analyzing the spectrum of light emitted or absorbed by substances, and is generally performed using ultraviolet, visible, or red spectroscopy. Examples include external spectroscopic analysis.

This spectroscopic analysis uses a spectrometer that disperses radiation from a light source into a spectrum and extracts desired monochromatic light.

An example of this conventional spectrometer will be explained with reference to FIG.

In FIG. 1, a conventional spectrometer includes a visible light source 1, an ultraviolet light source 2, and a light source mirror 3 that reflects light from the light source 2.
a filter 4 that absorbs or transmits a specific wavelength from
An entrance slit 5 through which the light transmitted through this filter 4 passes
A mirror 6 that reflects the light that has passed through the entrance slit 5, a concave mirror 7 that reflects and parallels the light reflected by this mirror 6, and a first plane diffraction that reflects and diffracts the parallel light reflected by this concave mirror 7. a grating 8, a parallel concave mirror 9 that reflects the light reflected and diffracted by the first flat diffraction grating 8, a mirror 10 that reflects the parallel light reflected by the concave mirror 9, and a mirror 10 that reflects the light reflected by the first plane diffraction grating 8; a slit 11 through which the
A mirror 12 on which the light passing through this slit 11 is reflected, and a concave mirror 1 on which the light reflected from this mirror 12 is reflected in parallel.
3, a concave mirror 15 that reflects and diffracts the light reflected and diffracted by this second plane diffraction grating 14; A mirror 16 that reflects light and this mirror 1
It has an exit slit IT through which the light reflected by 6 passes.

This conventional spectrometer uses a flat diffraction grating and a large number of mirrors, so there is a lot of light absorption by the mirrors, etc., and the drawback is that the energy of the monochromatic light emitted from the spectrometer is low, especially when the wavelength is in the ultraviolet region. Ta.

Furthermore, this conventional spectrometer has a complicated structure and is expensive to manufacture. An object of the present invention is to provide a spectrometer which eliminates the above-mentioned drawbacks and which emits monochromatic light with high energy.

Another object of the present invention is to provide a spectrometer that is simple in construction and inexpensive to manufacture.

Embodiments of the spectrometer of the present invention will be described below with reference to the drawings.

In FIG. 2, the spectrometer of the present invention includes a visible light source 21, an ultraviolet light source 22, a light source mirror 23 that switches between the two light sources 21 and 22, and a light source with a specific wavelength from the light source mirror 23. a first concave diffraction grating 25 that reflects and diffracts the light transmitted through the filter 24; and an entrance slit 26 through which the light reflected and diffracted by the first concave diffraction grating 25 passes. , a second concave diffraction grating 27 that further reflects and diffracts the light that has passed through the input slit 26, and an output slit 28 through which the light reflected and diffracted by the second concave diffraction grating 27 passes.

The light emitted from the visible light source 21 is reflected by the light source mirror 23,
The filter 24 is reached.

The light source mirror 23 switches the light from the visible light source 21 and the ultraviolet light source 22 by rotating. The light reaching this filter 24 selectively absorbs or transmits light of a predetermined wavelength, and reaches the first concave diffraction grating 25 . This first concave diffraction grating 25 is rotated because light of a specific wavelength is imaged at one point on the Rowland circle when light is emitted from a point on a Rowland circle whose diameter is the radius of curvature of the first concave diffraction grating 25. By doing so, a desired wavelength can be selected and passed through the entrance slit 26. The light reflected and diffracted by this concave diffraction grating passes through an entrance slit 26 and reaches a second concave diffraction grating 27 for further wavelength selection.

The light reaching the second concave diffraction grating 27 is further reflected and diffracted, and is emitted from the output slit 28 as monochromatic light.

As described above, the spectrometer of the present invention uses a filter and two concave diffraction gratings to select wavelengths at specific wavelengths, so it does not use mirrors such as collimators or concave mirrors, so light energy is reduced by light absorption. It is possible to emit monochromatic light with low loss and high optical energy, and its effect is particularly remarkable for light with a wavelength in the ultraviolet region.

Further, since the spectrometer of the present invention does not use a large number of mirrors such as a collimator and a concave mirror, the configuration is simple and the manufacturing cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an optical system of an example of a conventional spectrometer. FIG. 2 is an explanatory diagram of the optical system of an embodiment of the spectrometer of the present invention. 21... Visible light source, 22...
External light source, 23...Light source mirror, 25...
...first concave diffraction grating, 27...second concave diffraction grating, 28...output slit.

Claims (1)

[Claims] 1 At least two light sources, a light source mirror that switches the light sources, a first concave diffraction grating that collects, reflects, and diffracts the light from the light source mirror, and an incident light source through which the light from the first concave diffraction grating passes. A spectrometer comprising a slit, a second concave diffraction grating that reflects and diffracts light that has passed through the input slit, and an output slit through which light from the second concave diffraction grating passes.