SU648852A1 - Interference spectrometer - Google Patents

Description

The invention relates to technical physics and can be used in optical instrumentation, and for example in high resolution spectrometers.

Interference spectrometers are known in which there is no system for searching and stabilizing the amplitude of oscillations of an interference modulator 2.

Of the known interference spectrometers, the closest in technical essence is the interference spectrometer, the content of the interference modulator, the mechanism for setting the amplitude of oscillations of the interference modulator, connected in series with the receiver-recorder and frequency-selective unit 3.

The disadvantage of this spectrometer is the low accuracy of recording, since the amplitude of oscillations of the interference modulator is set manually.

The purpose of the invention is to improve the accuracy of spectrum recording by automatically searching for and stabilizing the optimal amplitude of oscillations of an interference modulator.

This is achieved by adding a vibrator, a synchronous distributor, a generator and a comparison unit to a known interference spectrometer, the generator is connected to a vibrator connected with the mechanism for setting the amplitude of oscillations of the interferon modulator, and a synchronous distributor, a synchronous distributor and a comparison device device is connected to the output of the frequency-selective unit through a synchronous distributor, and the output is connected to the mechanism for setting the amplitude of oscillations in terferential modulator.

The drawing shows the block diagram of the spectrometer.

The spectrometer has an interference modulator 1, a mechanism 2 for setting the amplitude of oscillations of an interference modulator. A 1, a receiving and recording device 3, a vibrator 4, a generator 5, a comparison unit 6, a frequency-selective unit 7 and a synchronous distributor 8. The generator 5 is connected to the vibrator 4, connected with the oscillation amplitude setting mechanism 2 of the interference modulator 1 by the n-synchronous distributor, the synchronous distributor 8, and the comparison device 6, the input of the comparison device 6 is connected to the output frequency-beat The power unit 7 via the synchronous distributor 8, and the output to the mechanism 2 for setting the amplitude of the oscillations of the interference modulator.

The spectrometer works as follows.

Modulator 1, periodically changing the path difference of the interferometer, produces selective modulation of the spectrum with a frequency WQ. A variable signal at this frequency is allocated by a receiving and recording device 3. Amplitude This signal is proportional to the Bessel function of the first kind of the first order of amplitude. oscillations of the interference modulator 1

T (V 2EG &.

1o

-li (Cg-),

BUT

where K is a parameter depending on the specific design of the modulator interference;

X is the wavelength for which the spectrometer is tuned.

Under the condition of an initial path difference & b, the Bessel function has a maximum at, which corresponds to the zero value of the first derivative. G Surveying the zero value of the first derivative and is provided by an automatic system in the spectrometer. The vibrator 4 oscillates the regulator of the amplitude setting mechanism 2 with the frequency f set by generator 5, much higher than the frequency wo. These oscillations cause periodic changes in the amplitude 1о of the variable component at the input of the synchronous distributor 8 by a value of ± D 1 °. The synchronous valve 8 divides the signal into two: la + A b and lo - L. b. which are then compared in block 6 of the comparison. The error signal, equal to the difference of these two signals, from the output of the comparison unit 6 controls the amplitude setting mechanism 2

so as to reduce the mismatch to zero. In this way, an automatic search and stabilization of the optimal amplitude of oscillations of the interference modulator 1 is carried out, which improves the accuracy of spectrum recording, as well as the speed of its registration.

Claims (3)

1. USSR Author's Certificate No. 138393, cl. G FROM I 3/20, 1960. 2. Seidel, AP and others. Technique and practice of spectroscopy. M., “Science, 1972, p. 208-212. 3.P. Pinson, "High resolution infrared spectrometer in the 8-10pm range, Appl. Opt. Vol. 13, 1974, No. 7, p. 1618.