An optical narrow-band filter based on a Bragg grating recorded in a microchannel waveguide filled with a photopolymer

摘要

The problem of creating a narrow-band filter that operates with wide-aperture (about 30°) light beams is solved in this paper. It describes the search for and the experimental certification of methods of creating a single-mode lightguide with a Bragg grating in it. An optical narrow-band filter is obtained by forming a Bragg grating in the microchannels of a fiber filled with a photopolymer. The proposed technology for filling the fiber ensures homogeneous filling of microchannels longer than 20 mm. The photopolymer composite thus developed makes it possible to obtain the photoinduced refractive-index modulation needed to record a grating in a solid composite. Such recording ensures that it is stable. The resulting temperature-stable filter can be used for spectral filtering of wide-aperture (about 30°) light beams.