In the 20th century, the research of the Fabry-Pérot (F-P) cavity mainly focused on basic optical properties and light source stabilization technology. However, with the development of quantum optics and nanotechnology, the research field of F-P microcavity has expanded rapidly in the 21st century. Nowadays, F-P microcavity is not only employed as an optical measurement tool, but also an important platform for studying the light-matter interactions to realize accurate parameter measurement, biological detection, and regulation for multi-dimensional light fields.

The F-P microcavity is an ideal tool for measuring the frequency of the light source and stabilizing the laser frequency due to its interference properties. The spectrometer based on the F-P microcavity can achieve very accurate spectral resolution, which can meet the demand for a wide range of fields from astronomical observation to optical fiber communication.

In terms of light-matter interactions, the F-P microcavity provides an ideal platform for exploring the coupling of photons and matter quantum systems. The photons in the microcavity can be strongly coupled with the material quantum systems such as atoms, molecules, or quantum dots, leading to some new physical phenomena. This provides possibilities for the development of new technologies such as quantum information processing based on light and ultra-low threshold lasers.

In precision parameter measurement, F-P microcavity is widely applied to measure physical parameters such as temperature, pressure, refractive index, and pressure due to its high sensitivity to small changes in the environment. By accurately measuring the changing interference mode of light in the microcavity, accurate information about the microcavity environment can be obtained to achieve a very accurate measurement. In biological detection, F-P microcavity is adopted to detect the characteristics of cells, viruses, proteins, and other biomolecules due to its high sensitivity to small changes in tissues. This is of significance for early diagnosis of diseases, pathological research, and other applications in the biomedical field. Additionally, F-P microcavity also plays an important role in multi-dimensional light field control by precisely controlling the microcavity.

First, the principle of the F-P microcavity is introduced based on thin-film optical theory (Fig. 1). The work progress of linear variable filter, integrated F-P filter, and reconfigurable spectrometer based on the F-P microcavity is presented according to the sequence of research development. The research team at Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, has carried out extensive research and application of linear gradient filter. In integrated F-P filter, Wang et al. from Shanghai Institute of Technical Physics, Chinese Academy of Sciences, proposed a method of combinatorial etching and deposition (Fig. 4) to prepare integrated F-P filter. As technology advances, nano-imprint lithography and grayscale lithography have also been applied to fabricate integrated F-P filter. F-P microcavities can be integrated with detectors, and the resulting spectrometers feature small size, light weight, and high stability. To overcome the difficulty in achieving high resolution in spectrometers based on F-P microcavities and the associated manufacturing challenges, spectral reconstruction algorithms have been introduced to significantly improve the spectral resolution of spectrometers. In the interactions between photons and low-dimensional materials in an all-dielectric F-P microcavity, low-dimensional semiconductor lasers based on all-dielectric F-P microcavities are introduced first. Based on the theory of cavity quantum electrodynamics, the weak and strong coupling interactions between light and low-dimensional materials are discussed. With the developing fabrication technology of two-dimensional materials, researchers continued to deepen the research on light-material interactions in microcavities, and strong coupling phenomena and research related to exciton-polariton lasers have gradually been reported.

In F-P microcavity applications, its application in precision parameter measurement is first introduced. Due to the high-quality factor and strong resonance effect of the F-P microcavity, researchers have achieved precision measurement of parameters such as environmental refractive index, temperature, humidity, pressure, and sound through the utilization of optical fibers and corresponding sensing materials. Meanwhile, the teams of Lu Wei and Wang Shaowei from Shanghai Institute of Technical Physics, Chinese Academy of Sciences, have further expanded the measurement field to achieve measurements of the complex refractive index of low-dimensional materials of tiny dimensions. In biological detection, the F-P microcavity can be employed to reveal the characteristics of cells and biomolecules, describe changes in internal molecular interactions, and aid in the detection, identification, and imaging of biomolecules. In multi-dimensional optical field control, by combining the high quality factor of the F-P microcavity, narrow spectral features, and introduction of emerging micro/nano devices such as metasurfaces, it is possible to achieve control and generation of polarization/spectrum, beam shaping, and vortex light fields. This lays the foundation for high-performance and multi-functional optical field control.

This review summarizes the research progress in optical field control in F-P microcavities over the past 20 years. The research is focused on the introduction of spectroscopic structures and spectroscopic detection applications based on F-P microcavities, the interaction study of photons with low-dimensional materials in F-P microcavities, and potential applications of F-P microcavities in precision measurement of parameters, biological detection, and multi-dimensional optical field control. Further exploration and in-depth studies are essential for issues such as optimizing the design of the microcavity, accurately manipulating its parameters, and enhancing its stability. The research field of F-P microcavities will be further expanded.