SU474165A3 - Spectrometer - Google Patents

Description

(54) SPECTROMETER

Image refers to the field of spectral instrumentation.

In the known single-wave spectrometers, the modulation of the radiation flux at a selected wavelength is produced by raster vibration, while its image projected by the spectrometer optics in the raster plane vibrates in antiphase.

The proposed spectrometer allows an increase in the modulation depth on the selected LENGTH of the wave. This is achieved by introducing additional reflective elements into the optical scheme of the spectrometer, which allow to project its enantiomorphic image in the raster plane (the enantiomorphic image of the object is understood as the symmetric image of the specified object relative to any plane). In this case, as the raster rotates, its image rotates in the opposite direction.

Additional reflective elements are made in the form of a reflecting dihedral.

Reflective dowy. Can be made turning m.

The raster of the spectrometer can also be made turning.

The incoming and outgoing radiation fluxes fall on the opposite sides of the raster or on the same side of the raster.

FIG. 1 shows one type of raster.

used in the described mm spectrometer; in fig. 2-4 variants of optical schemes of a single-beam spectrometer; in fig. 5 and 6 is the same two-beam spectrometer; in fig. 7- dependence of the output flux on the angle of rotation of the raster relative to its image in the single-beam spectrometer scheme; in fig. 8 shows the dependences of the output streams attacking different radiation receivers on the angle of rotation of the raster in the circuit shown in FIG. five.

The raster used in the spectrometer is worthy of having a rotation symmetry on the order of 2iV. When turning the raster on l radians around the axis,

lying in its plane and passing along the zone boundary, the outlines of the zone boundaries occupy a position that is no different from the original. The same is observed when the raster is rotated on a radian around an axis,

the polol m passing through its center and dividing the zone, i.e., the outlines of the borders of the raster zones are known to themselves as self-similarly for both indicated axes. The raster zone configuration is enantiomorphic to itself only for the second axis.

The spectrometer (see Fig. 2) works as follows.

The radiation from the light source 1 passes through the lower half of the raster 2, whose center is in the focus of the collimator 3,

formed by this collimator into a parallel beam, passes the dispersing element nt 4 and then the reflecting dihedral 5 is again sent to the dispersing element. After re-passing the dispersing element, the radiation of the selected wavelength is focused by the collimator 3 on the upper part of the raster 2.

At the same time, due to the introduction of an additional reflecting element (instead of one flat mirror, a mirror dihedral is applied) and the upper part of the raster, a one-color enantiomorphic image of the lower part of the raster is formed. When the raster rotates around axis 6 passing through the center of perpendiculars of its plane, the radiation flux at the selected wavelength, which falls after reflection from pacTipa to receiver 7, is amplitude modulated, as the raster image rotates in the opposite direction. Spectrum scanning is performed by rotating the dispersing element around the axis 8. The raster image is rotated relative to the raster itself can be done by rotating the dowel 5 around the axis 9, while the raster can remain fixed.

FIG. Figure 3 shows a spectrometer in which a diffraction grating 10 and a mirror collimator I. are installed instead of a prism and a lens collimator. Radiation fluxes entering and leaving the spectrometer fall on different sides of the raster, and the number of reflections in the spectrometer must be even, m.

In the spectrometer (ohm. Fig. 4), the incoming and outgoing radiation fluxes fall on the same side of the rastvore, and the number of reflections in the spectrometer must be odd. In the optical scheme of such a spectrometer, there is no mirror dihedral, and the enantiomorphic image of raster 2 is formed in its plane using flat mirrors 12 and 13, one of which is installed along the beam between the raster and the collimator 11, and the other between the collimator and the raster. Modulation is performed by rotating the raster.

The dual beam spectrometer (see Fig. 5) differs from that shown in Fig. 3. the presence of a divider 14 of the light flux and two spherical mirrors 15 and 16, sending the radiation of the source 1 of light into the spectrometer. The radiation emitted from the spectrometer can be registered by receiver 7 or 7, or by two receivers at once, while

Each of the receivers receives luminous flux from both channels.

Radiation fluxes from different channels, arriving at any receiver, are duplicated in antiphase, and the variable signal at the receiver output appears only when the radiation fluxes go through different channels.

At the same time, radiation flows modulated along one of the channels, but falling into different receivers, are modulated in antiphase.

The double-beam spectrometer (see FIG. 6) also contains a light divider 14,

coming from source 1, and mirrors 15 and 16, sending radiation to the spectrometer through two channels. The operation of the spectrometer is similar to that of the spectrometer shown in FIG. 4. At the selected wavelength light

The streams arriving at the receiver from different channels are modulated in the opposite phase; therefore, the variable signal at the receiver output is proportional to the difference in the light fluxes that pass the spectrometer through different

channels.

The upper graph in FIG. 8 represents the dependence of the light fluxes on the angle of rotation at the receiver 7, while the flat line shows the course of the change in the flux going through the neipeoMy channel, and the second through it. The lower graph refers to the signals at receiver T.

Subject invention

Claims (6)

1. A spectrometer containing a raster with rotation symmetry on the order of 2L, a dispersing device and a collimator, characterized in that, in order to increase the modulation depth at a selected wavelength, additional reflective elements are introduced into it. 2. A spectrometer according to claim 1, characterized in that the additional reflecting elements are made in the form of a reflecting dihedral. 3. Spectrometer on the PP. 1 and 2, characterized in that the reflecting dihedral is rotatable. 4. The spectrometer according to claim 1, characterized in that the raster in it is made rotatable. 5. Optro; meT | p according to claim 1, characterized in that the incoming and outgoing radiation fluxes fall on opposite sides of the raster. 6. A spectrometer according to claim 1, characterized in that the incoming and outgoing radiation fluxes fall on the same side of the raster. Fig 3 FIG. t FIG. li 2fC 5ft 2l y: 33333 1B Physical § phage.7 f 2 1g 2 , 2 Fz 2 A