Micromodification of Metal Oxides and Their Applications in Fiber‐Optic Sensing: A Review

Environmental issues such as harmful gas leaks and water pollution continue to threaten people's property and life safety. Proposing a high‐performance sensor has become a focus of attention for researchers. Fiber‐optic sensors are considered the most promising type of sensor due to their high sensitivity, strong anti‐interference ability, small size, and low cost. However, to enhance the selectivity and high sensitivity of fiber‐optic sensors, sensitive thin films are essential. Metal oxides have good sensitivity to specific environmental parameters and can be monitored through changes in their properties, thereby improving the sensitivity and response speed of fiber‐optic sensors. This article provides a detailed introduction to the latest research progress on doping and heterojunction modification of metal oxides. In addition, the latest research progress on the application of metal oxides in the field of fiber‐optic sensors is summarized, including the preparation of modified metal oxides, coating methods for fiber surfaces, and the application of metal oxide‐coated fiber‐optic sensors in gas and liquid environments. Finally, a summary and outlook are provided on the current research gaps and future development prospects.