Design of near infrared bandpass filter using all-solid photonic crystal fiber with parasitic bandgaps suppression

In this work, an approach of realizing fiber-based near infrared bandpass filter with parasitic bandgaps suppression is proposed. By doping the core of an all-solid photonic bandgap fiber with lower refractive index material, single-mode light is confined in the main bandgap centered at 1.0 μm wavelength region. Light guiding in higher order bandgaps is suppressed due to the coupling of light to the cladding region. The proposed design is suitable for realizing in-fiber single-band broadband light filter with possible applications in lasing, spectroscopy and optical communication.