Bragg Fiber Optoelectronic Applications: Optical Inline Filters for Multiwavelength Applications

Previous chapters have extensively discussed the various potential applications of Bragg fiber (BF) structures as sensors for detecting bio/fuel adulteration. These sensors rely on wavelength and intensity modulation in defect signals to achieve optimal sensing performance. Compared to other sensing methods such as planner photonic crystals, photonic crystal fibers, and surface plasmon sensors, BFs offer superior sensing behavior. Furthermore, we have noticed that the BF sensor has superior sensing capabilities compared to other existing methodologies or systems. In this current chapter of the book, we have examined a possible use in the field of optoelectronics. This chapter presents a detailed analysis of doubly tuned Bragg fibers that are used as low-power optical inline filters (OIFs). The filters have been modeled, designed, and studied using a voltage-tunable single-crystal PMMA polymer defect cavity. The analysis is conducted using Hankel formalism in a cylindrical coordinate system, specifically for multiwavelength LASER applications. The structure of the BFs exhibits a photonic band gap (PBG) that produces a resonant transmission signal inside the PBG area. The thickness of the PMMA fault cavity is regulated by the application of an external direct current (DC) voltage. The suggested OIFs can achieve a tunable PBG of up to 828 nm by changing the incidence angle up to 800. Therefore, the transmission signal that resonates is moved towards the blue end of the spectrum by 243 nm. This shift may be further adjusted by applying DC voltages, a phenomenon known as double electrically tuning. In addition, when operating in the doubly electrically tuned mode, this optoelectronic device has a significantly wide application range of up to 129 nm. This wide range may be achieved with a relatively modest change in voltage, typically about 20 V. Therefore, the current technology may be employed as a multiwavelength LASER source.