Fiber-optic Sensors with Microsphere

In this chapter, fiber-optic sensors integrated with optical microspheres have been presented. Fiber-optic microspheres are microscopic light spheres widely used in research and various kinds of industries. With the development of optical fiber technology in recent years, they are being increasingly used in the construction of fiber-optic sensors. They are mainly used as microresonators and whispering gallery mode sensors. However, research published in the last few years shows various new possibilities and prospects of using such devices. The method of producing a microsphere has been discussed in this chapter. Furthermore, optimization of fiber-optic sensors integrated with optical microspheres by tuning of thin Atomic Layer Deposition (ALD) metal-based coatings has also been presented. Zinc oxide (ZnO) of various thickness is deposited on the surface of the sensor head using the ALD method.