Научно-исследовательский институт физико-химической биологии им. А.Н. Белозерского
Limited operating bandwidth originated from strong absorption of glass materials in the infrared (IR) spectral region has hindered the potential applications of microstructured optical waveguide (MOW)-based sensors. Here, we demonstrate multimode waveguide regime up to 6.5 µm for the hollow-core (HC) MOWs drawn from borosilicate soft glass. Effective light guidance in central HC (diameter ∼240 µm) was observed from 0.4 to 6.5 µm despite high waveguide losses (0.4 and 1 dB/cm in near- and mid-IR, respectively). Additional optimization of the waveguide structure can potentially extend its operating range and decrease transmission losses, offering an attractive alternative to tellurite and chalcogenide-based fibers. Featuring the transparency in mid-IR, HC MOWs are promising candidates for the creation of MOW-based sensors for chemical and biomedical applications.