Interferometric methods for suppressing additive noise

Abstract

Abstract-Interferometric methods for signal processing, which make it possible to obtain a better noise protection of information laser and optoelectronic systems during detection and processing of optical fields under conditions for external additive noise, are proposed based on the results of analysis of the specific features of field formation in passive and active optical interferometers. The possibility of reducing the effect of external factors on the efficiency of additive-noise suppression by supplementing an interferometer with a stimulated-Brillouin-scattering fiber mirror is investigated. The technical feasibility of the methods proposed is shown and their efficiency is experimentally confirmed. IN T R O D U C T IO NThe rapid progress of laser and optoelectronic technologies in all fields of fundamental and applied research gave a new impetus to the development of optical interferometry and made it possible to expand significantly its application range. Currently, interferometric methods are an actively developing line of research in physical and applied optics, which uses the latest achievem ents of laser technique, opto electronics, and fiber optics and is applied in various fields. Currently, double-beam interferometers (such as M a c h -Zehnder interferom eter and its various m odifications) are widely used in designing highly sensitive precise optical sensors and gyroscopes and in other important fields of scien ce and technology, including astrophysical system s for observing dis tant ob jects and system s for diagnostics of various physical processes (see, for example, [1 -8]). The con stan t interest in the transform ation of optical fields by interferometric m ethods is related to the possibility of im plem enting direct optical processing of optical fields and controlling their spatial and temporal structure. At the sam e tim e, an analysis of the modern state of the problems related to the de velopment and application of interferometric methods shows that their unique potential for various applied problems has not been realized and implemented in E-mail: n i k i t i n @ b s u .e d u .r u E-mail: s a u tk in @ z e n it-k m z .r u E-mail: v n fo m in @ y a n d e x .ru E-mail: A .T s e r e v iti n o v @ y a n d e x .r u full m easure. Thus, there is a wide area of activity for researchers and experts in this field.Here, we consider one of applications of interferometric m ethods aimed at improving the noise protection of laser and optoelectronic information system s applied in detection and processing of optical fields under conditions of external additive noise. SP A T IA L AN D T E M P O R A L S E L E C T IO N O F N O IS E IN A P A S S IV E IN T E R F E R O M E T E R Formation o f Fields in a Passive InterferometerLet us consider some specific features of field for m ation at outputs of a passive optical interferometer. Generally, interferometer arm s are characterized by som e relative temporal and spatial m ism atch, which is caused by various factors. The spatial wave m is m atch (Аж) in...