There has been a surge of interest in recent years for the advancement of wide bandgap oxides such as zinc oxide (ZnO), magnesium oxide (MgO), gallium oxide (Ga2O3), etc. [1,2]. These materials have gained significant attention due to their distinctive characteristics and properties which are promising for the development of high-performance optoelectronic devices for applications in the domains of sensing, communications, and imaging. More specifically, Ga2O3 has wide bandgap energy of approximately 4.8 to 4.9 electron volts (eV), thus exhibiting exceptional transparency to ultraviolet (UV) radiation while displaying opaqueness to visible light [3]. On a parallel note, ZnO shows exemplary optical and electrical properties, including a high exciton binding energy and substantial oscillator strength [4]. Of particular significance is the exploration of intersubband transitions within multiple quantum well (MQW) structures, which offers a promising path for efficient light absorption and emission in the mid-infrared to terahertz spectral range. In this contribution we will numerically simulate the absorption spectra of the wide bandgap oxide MQW structures, adapting the approach for treating the light-matter interaction suitable when the depolarization field is the dominant many-body contribution, and discuss the potential applications in optoelectronic devices, specifically mid-infrared detectors, quantum cascade lasers, and modulators.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad