Due to numerous advantages of optical fiber sensor OFS over conventional electrical sensors, many FOS researches have been conducting up to date. One of the important FOS technologies is Fiber Bragg Grating FBG sensing. FBG sensor has been employed to sensing different physical measurands, for example, strain, temperature, pressure/acoustics, displacement, torsion, rotation … etc [1–4]. The majority of studies have been done with FBG based silica fiber which gave efficient sensitivity outcomes. However, changing the silica fiber with polymer is still a matter of challenge. Nonetheless, recent relevant polymer researches showed a quantum leap in terms of physical parameter sensitivity, for example, pressure [5–9]. One of the most promising polymer materials is called perfluorinated polymer CYTOP (poly(perfuorotenyl vinyl ether)) which has been implemented in the OFS technologies. Most of the important key features of the CYTOP compared with silica fiber are handling safe, low cost, conformity with biomedical and organic materials [10–15]. The CYTOP has significant characteristics in thermal, surface features, chemical, and electrical aspects. Moreover, the CYTOP has a wide transmission window about (650-1300 nm); at 1300 nm CYTOP reaches less loss about 15 dB/Km. In terms of optical properties, the CYTOP has a low core refractive index of 1.3335 at 1.55 µm with a significant low loss of about 75 dB/Km. Furthermore, the CYTOP is approximately transparent material for wavelengths (0.2-2 µm). It has a minimum dispersion and maximum abbe number values among the optical polymer [16–21]. Moreover, the CYTOP material has excellent stability of mechanical and optical features in humidity circumstances, so this is the reason behind involve it in humidity sensor applications [22]. Additionally, the chemical structure of CYTOP contrary to other polymer materials; the CYTOP has Hydrogen free in the main chain instead there are Fluorine F atoms. This explains the low loss of CYTOP fiber [23–26]. Different methods of fabrication of CYTOP FBG have been reported in recent researches. The most common methods are ‘amplitude splitting technique’, ‘phase mask technique’, ‘femtosecond laser technique’, ‘point by point and line by line method’, and ‘Nd: YAG laser pulse method’. Because of the outstanding features of CYTOP fiber, it has been used in different applications such as fiber laser, fiber communication, a mechanical sensor, strain monitoring, composite material monitoring, robotic application, health equipment, and an ultrasound sensor. However, this paper presents a method of enhancement pressure sensitivity of FBG based on CYTOP fiber, so the principle of working of the FBG sensor needs to be illustrated first [23–29].