Interferometer to Control Wedge Angles

Authors: Timashova L.N., Kulakova N.N. Published: 06.06.2020
Published in issue: #2(131)/2020  
DOI: 10.18698/0236-3933-2020-2-117-129

Category: Instrument Engineering, Metrology, Information-Measuring Instruments and Systems | Chapter: Optical and Optoelectronic Instruments and Complexes  
Keywords: optical wedge, planar wafer, interferometer, interference pattern, interference fringe, optoelectronic system, objective lens, image sensor, measurement error, laser

The paper considers an optoelectronic laser interferometer system to control wedge angles. This system records an interference pattern on an image sensor. The interferometer makes it possible to estimate the small angle of the wedge under investigation by the variation it introduces into the shape of the optical radiation wavefront, which the interferometer then converts into changing the size of the interference pattern. In the interferometer considered, the wedge under investigation refracts the incident ray cone. The error inherent in surface finishing causes the deformation of the working wavefront to be 2 to 4 times smaller as compared to the deformation in previously known control setups involving reflection from the wedge surfaces. The interferometer developed ensures highly accurate control of wedge angles at the surface polishing stage, including potential detection of wedge direction. If required, the interferometer may be used for comprehensive quality control of wedge manufacturing, assessing not only the surface nonplanarity, but also glass inhomogeneity; it may also be used to control prism angles


[1] Krivovyaz L.M., Puryaev D.T., Znamenskaya M.A. Praktika opticheskoy izmeritel’noy laboratorii [Practice of optical measuring laboratory]. Moscow, Mashinostroenie Publ., 2004.

[2] Kreopalova G.V., Puryaev D.T. Issledovanie i kontrol’ opticheskikh system [Study and control on optical systems]. Moscow, Mashinostroenie Publ., 1978.

[3] Kreopalova G.V., Lazareva N.L., Puryaev D.T. Opticheskie izmereniya [Optical measurements]. Moscow, Mashinostroenie Publ., 1987.

[4] Malacara D. Optical shop testing. Wiley, 2007.

[5] Andreev A.N., Gavrilov E.V., Ishanin G.G., et al. Opticheskie izmereniya [Optical measurements]. Moscow, Logos Publ., 2008.

[6] Kirillovskiy V.K. Opticheskie izmereniya. Ch. 2. Teoriya chuvstvitelʼnosti opticheskikh izmeritel’nykh navodok. Rol’ opticheskogo izobrazheniya [Optical measurements. P. 2. Sensitivity theory of optical measuring sighting. Role of optical image]. St. Petersburg, ITMO Publ., 2003.

[7] Schroder G., Treiber H. Technische optik: grundlagen und anwendungen. Vogel, 2002.

[8] Mishin S.V., Kulakova N.N., Tirasishin A.V. Adaptation of the algorithm for searching the coordinates of the energy centre in the image of an autocollimating point for working with digital autocollimator. Vestn. Mosk. Gos. Tekh. Univ. im. N.E. Baumana, Priborostr. [Herald of the Bauman Moscow State Tech. Univ., Instrum. Eng.], 2016, no. 2, pp. 117--124 (in Russ.). DOI: http://dx.doi.org/10.18698/0236-3933-2016-2-117-124

[9] Timashova L.N., Kulakova N.N., Sazonov V.N. Opto-electronic system for measurment of spherical aberration. Vestn. Mosk. Gos. Tekh. Univ. im. N.E. Baumana, Priborostr. [Herald of the Bauman Moscow State Tech. Univ., Instrum. Eng.], 2018, no. 6, pp. 112--122 (in Russ.). DOI: http://dx.doi.org/10.18698/0236-3933-2018-2-112-122

[10] Kulakova N.N., Kaledin S.B., Sazonov V.N. Error analysis of IR lens focal length measured by a goniometric method. Vestn. Mosk. Gos. Tekh. Univ. im. N.E. Baumana, Priborostr. [Herald of the Bauman Moscow State Tech. Univ., Instrum. Eng.], 2017, no. 4, pp. 17--26 (in Russ.). DOI: http://dx.doi.org/10.18698/0236-3933-2017-4-17-26

[11] Mosyagin G.M., Nemtinov V.B., Lebedev E.N. Teoriya optiko-elektronnykh system [Theory of optical electronic systems]. Moscow, Mashinostroenie Publ., 1990.

[12] Yakushenkov Yu.G., ed. Proektirovanie optiko-elektronnykh priborov [Design of optical electronic devices]. Moscow, Logos Publ., 2000.

[13] Yakushenkov Yu.G. Teoriya i raschet optiko-elektronnykh priborov [Theory and calculation of optical electronic devices]. Moscow, Logos Publ., 2004.

[14] Korotaev V.V. Raschet shumovoy pogreshnosti optiko-elektronnykh priborov [Calculation of noise error of optical electronic devices]. St. Petersburg, ITMO Publ., 2012.

[15] Zakaznov N.P., Kiryushin S.I., Kuzichev V.I. Teoriya opticheskikh system [Theory of optical systems]. St. Petersburg, Lan Publ., 2008.