Structures and devices built using microspherical building blocks attract significant attention in recent years due to an extraordinary high-quality factor (Q>106) of whispering gallery modes in dielectric microspheres and due to their ability to tightly focus light – so-called "photonic nanojets." In this Ph.D. theses work, we explore these properties in much more sophisticated structures where the microspheres are brought together to form so-called "photonic molecules" and 2-D arrays, where the individual resonant modes are strongly coupled forming optical supermodes with novel properties.Chapters 2 and 3 are devoted to resonant coupling properties of such photonic molecules and sensor devices. Through finite difference time domain modeling, we introduce novel properties of such structures such as spectral signatures of photonic molecules. We show that the spectral signatures are determined by the number and configuration of constituting photonic atoms. We study spectral and spatial properties of the optical supermodes in different molecules. We also demonstrate how the simplest bi-atomic molecules can be used for achieving routing and switching functionality in 4-port structures where such molecules are coupled to stripe waveguides. Chapter 4 is devoted to application of photonic nanojets for enhancing the collection of light and angle-of-view (AOV) in midwives-infrared focal plane arrays. The problem in this area is related to the thermal noise in uncooled cameras. We show that we can tackle this problem by designing devices integrated with microspheres where the size of the pixels can be significantly reduced to decrease the noise, still keeping high photon collection efficiency and large AOV, thus allowing increasing the operation temperature.Chapter 5 is devoted to application of microspheres for superresolution imaging. The problem in this area is related to an intriguing role which nanoplasmonic plays in achieving optical superresolution properties. By performing extensive comparative nanoscale imaging of fluorescent nanospheres through silica microspheres (index n=1.46), we experimentally demonstrate an important role which localized surface plasmon resonances in different metals such as Au and Al play in superresolution properties of such devices. We demonstrate that the virtual imaging of fluorescent nanospheres is possible with /6 resolution, if the size of features and periods of nanoplasmonic arrays is sufficiently small.