Measuring instrument and method for temperature coefficient of optical glass refractive index

Abstract

The invention discloses a measuring apparatus for optical glass refractive index temperature parameters which includes an optical source and a Mach-Zehnder interferometer consists of four reflectors. The interferometer is provided with a glass stick with two parallel end surfaces. An optical axis of the glass stick is coincident with an optical axis of the interferometer and the two ends of the interferometer are respectively provided with a first pinhole diaphragm and a second pinhole diaphragm. A silicon photodiode used for measuring the changes of interference fringes formed at the end surfaces of the glass stick is arranged near the first pinhole diaphragm and a silicon photoelectric generator used for measuring the changes of the Mach-Zehnder interference fringes is arranged near the second pinhole diaphragm. The invention is characterized in that the glass stick is provided with a heating furnace and has the advantages of giving a heating furnace structure which realizes an axial symmetry temperature field and proposing a detail measuring method; the refractive index temperature coefficients and the heat expansion coefficients of a certain temperature range during one measurement can be simultaneously obtained according to the measuring method and the micro-expansion coefficients (10<-7> DEG C<-1> ) of low expansion glasses can also be measured.

Description

technical field [0001] The invention relates to an optical instrument, in particular to an optical glass refractive index temperature coefficient measuring instrument and a measuring method thereof. Background technique [0002] In optical design, in order to consider eliminating thermal aberration caused by temperature changes of optical components, it is necessary to know the temperature coefficient of refractive index of optical glass. In addition to the glass refractive index, the foreign optical glass product catalog also gives the refractive index temperature coefficient, the thermal expansion coefficient at room temperature (below 100°C), etc., while the Chinese optical glass product catalog is still blank, and has not yet been included in the national standard. These parameters, the sporadic data given by a few manufacturers are copied from foreign product catalogs with similar glass components. In July 1982, the Acta Optics Sinica reported the thermo-optic coeffici...

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Problems solved by technology

In July 1982, the Acta Optics Sinica reported the thermo-optic coefficient of optical glass and its measurement principle. In August 1987, it reported the thermo-optic coefficient instrument. These two reports gave the measurement principle of the thermo-optic coefficient, but did not give The realization of the measurement principle requires the specific structure and measurement method of the special temperature field

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