Designing cladding mode interference device – a host for sensors and all-fiber inline gain-flattening component and broad-band filter

AbstractThis article describes how to devise interference and self-imaging of core and cladding modes based devices using dissimilar core concatenated all-fibers. The core diameter mismatch in the structure excites the cladding modes with the core mode that leads to a progressive interference imaging between the cladding modes and the core mode yielding wavelength and refractive index dependent loss. Through a systematic study, we tune the device parameters to gauge temperature and concentration with sensitivity of 0.0713 dB/°C and 0.0372 dB/(% mL/mL) respectively as a high-performance fiber sensor. Next, optimizing the wavelength sensitive parameters of the host configuration, we investigate the transmission characteristics as gain-flattening filters (GFF) of Erbium-doped fiber amplifiers (EDFAs) with maximum gain variations of 0.91 and 0.97 dB, for two different EDFAs respectively over a wavelength band of 33 and 25 nm. Finally, we demonstrate a tunable and two-flattop band rejection filters with rejection band of 14, 26 and 46 nm, respectively.KEYWORDS: Core–cladding mode interferencefiber optic temperature and concentration measurementEDFA gain flatteningband rejection filter Disclosure statementNo potential conflict of interest was reported by the author(s).Data availabilityThe information applied in this research is ready from the authors at request.Additional informationNotes on contributorsProtik RoyProtik Roy received his BSc degree in Physics from the University of Calcutta, West Bengal, India, in 2016 and his MSc degree from the Indian Institute of Technology, Kanpur, Uttar Pradesh, India in 2018. In 2019, he joined the Department of Physics, Indian Institute of Technology, Kharagpur, West Bengal, India, as a Research Scholar where since then, he has been working in the broad area of optics and photonics for this PhD research. His main research interest is to develop cladding mode based devices and sensors.Partha Roy ChaudhuriPartha Roy Chaudhuri is a Professor of Physics at Indian Institute of Technology Kharagpur, working in the area of Fiber and Integrated Optics and Photonics. In 2000, he did his PhD from the Fiber Optics Group of Indian Institute of Technology Delhi. He then pursued postdoctoral research at the Kyoto Institute of Technology, Japan, as a Japanese Government Fellow where he was working on various optical waveguides and components. Later, during 2002–2004, he worked at the Institute for Communications Research, NUS, in experimental research with photonic crystal fibers and components. In 2004, he joined the Faculty of the Physics Department, IIT Kharagpur, India. His current research interests are in the area of microstructured optical fibers/photonic crystal waveguides and devices for passive and active/nonlinear applications and development of fiber optic sensors for the detection of weak electric and magnetic fields.