RU2019796C1 - Device for measuring polarization composition of radiation in real time scale - Google Patents

Abstract

FIELD: test equipment. SUBSTANCE: device has collimator 1, polarization analyzer 2 with four optical outputs, connected with inputs of four detectors 6. Signal from the photodetectors is processed by unit 7 and is applied to indication system 8. Polarization analyzer has semi-transparent diffraction grating 3, which splits irradiation under test to four beams. Any beam is analyzed by means of polarizers 4 and unit formed by quarter-wave plate and polarizer 5. All four parameters of the grating are measured simultaneously by means of the analyzer. EFFECT: improved precision. 1 dwg

Description

 The invention is intended for use in optical installations for various purposes, in particular in pulsed systems for remote monitoring of physical processes by optical methods.

 A device comprising an optically coupled collimator, a polarization converter made in the form of an electro-optical modulator, a polarization analyzer with four optical outputs connected to the inputs of four photodetectors, connected to a signal preprocessing system and a signal registration system, a polarization analyzer is made in the form of two polarizing prisms, combined non-working side faces.

 A disadvantage of the known device is the division of the wavefront in the measurement process into several parts.

 The purpose of the invention is to increase the speed and accuracy of measurements.

 The goal is achieved by the fact that in the known device for measuring the polarization composition of radiation containing optically coupled collimator, a polarization analyzer with four optical outputs optically coupled to the inputs of four photodetectors and a signal preprocessing system connected to the signal registration system, the analyzer is made in the form of a translucent diffraction grating, in the direction of the first maxima of which, in the reflected and transmitted light, dipholes oriented with respect to the strokes are installed ktsionnoy grating polarizers or blocks comprising a polarizer and a quarter-wave plate, polarizers and installed so that at least one pair of polarizers mounted on one side of the grating are oriented mutually orthogonally.

 The drawing shows a diagram of the proposed device.

 The device comprises a collimator 1, a polarization analyzer 2 located directly behind the collimator 1 on the optical axis and made in the form of a translucent diffraction grating 3, the lines of which are perpendicular to the plane of the polarization analyzer 2, in the direction of the first maxima of the grating 3 in the reflected and transmitted light are set perpendicular to these directions polarizers 4 and sets of a quarter-wave plate and polarizer 5, oriented relative to the strokes of the diffraction grating 3 and forming an optical polarization analyzer outputs 2; photodetectors 6, the optical outputs of which are combined with the outputs of the polarization analyzer 2; a signal pre-processing system 7, the inputs of which are connected to the outputs of the photodetectors 6, and the output is connected to the input of the signal registration system 8.

 The device operates as follows.

 The studied radiation is incident on the collimator 1 along the optical axis, a parallel light beam is incident along the optical axis on the polarization analyzer 2. The light from the polarization analyzer 2 using the diffraction grating 3 is divided into four beams that are incident on the polarizers 4 and a set of quarter-wave plate and polarizer 5. After passing through the polarization analyzer 2, the radiation enters the photodetectors 6, at the outputs of which electrical signals are generated that carry complete information about the polarization composition. of radiation.

When implementing the proposed technical solution, a certain difference arises in the path of the optical signal passing through the polarizer and a set of a quarter-wave plate and a polarizer, which can introduce a certain error in the measurements. To eliminate this error, it is desirable to use a pair of sets of a quarter-wave plate and a polarizer, which are placed either behind or before the diffraction grating, the polarizers of which are oriented at an angle of 45 and 135 ^about . From the measured signals, all four Stokes parameters can be calculated.

 The invention allows to sharply increase the speed of the device by eliminating multi-time measurements using an electro-optical modulator and performing simultaneous measurements using stationary quarter-wave plates, as well as improving the accuracy of measurements of fast processes.

Claims (1)

 REAL-TIME DEVICE FOR MEASURING THE POLARIZATION COMPOSITION OF RADIATION, containing optically coupled collimator, a polarization analyzer with four optical outputs, optically coupled to the inputs of four photodetectors and a signal preprocessing system connected to the signal recording system, characterized in that it increases the speed of and accuracy of measurements, the analyzer is made in the form of a translucent diffraction grating, in the direction of the first maxima of which in the reflected and In the light of the past, polarizers or blocks oriented relative to the strokes of the diffraction grating are installed, containing polarizer and a quarter-wave plate, and the polarizers are mounted so that at least one pair of polarizers mounted on one side of the diffraction grating are oriented mutually orthogonally.