Some recently developed systems focus on solving these challenges through scalp-located semiconductor technology. However, the use of avalanche photodiodes (APDs) limits the SNR and the sensitivity at large SDSs [13] and single photon avalanche diodes (SPADs), have a very small detection area, limiting photons harvesting from the scalp. Therefore, SPADs are better indicated for time domain systems [14] employing time-correlated single photon counting that needs particularly complex hardware. It was recently demonstrated that silicon photomultipliers (SiPMs), which constitute an array of SPADs read in parallel, are very promising to further advance fNIRS for human brain cortex monitoring [15; 16; 17; 18]. The advantages of SiPMs arise from the combination of having a high gain, of the order of 10\({}^{6}\)-10\({}^{7}\) electrons per detected photon, like a conventional vacuum photomultiplier, coupled with a large detection area, low operation voltage, small size, high robustness and reliability, low cost, and high SNR [19]. Thanks to the SiPM high gain, it is possible to design systems with different and large SDSs, allowing overlapping measurements and producing significant improvement in localization accuracy in optical brain imaging systems both in time domain [20; 21] and continuous wave [22]. However, SiPMs have a relatively modest linearity region if compared to most of the other semiconductor photodetectors. In fact, a SiPM is an array of SPADs with resistors or active quenching circuits in series. Since the quenching time, though short, is finite, the maximum photon flux in the linear regime that can impinge on the SiPM can be estimated as N\({}_{\text{pixel}}\)/(EQE \(\cdot\) T\({}_{\text{quench}}\)), where T\({}_{\text{quench}}\) is the average avalanche quenching time for each pixel, of the order of nanoseconds; EQE is the external quantum efficiency i.e. the ratio of the number of charge carriers to the number of incident photons, and N\({}_{\text{pixel}}\) is the number of SiPM pixels, ranging from hundreds to thousands, in commercial devices. Vice versa, the minimum limit of detectable photon flux is 3 dB above the level of the dark current related to the dark count, equal to N\({}_{\text{pixel}}\)/t\({}_{\text{dark}}\) where 1/t\({}_{\text{dark}}\) is the dark count rate of a single pixel of the device [23]. The time scales of these phenomena (avalanche quenching and dark count) are relatively close, and therefore substantially limit the useful range of impinging optical power for the linear SiPM operation. This should be carefully considered when designing a brain imaging system based on SiPMs. In this paper, by using SiPMs in their linear regime, we demonstrate the feasibility of a SiPMs and light emitting diodes (LEDs) based optical imaging system able to perform a large number of overlapping measurements by exploiting SDSs from 2 to 10 cm, in a phantom with near-infrared light scattering and absorption characteristics close to human head tissues. The apparatus is a continuous wave (CW) system suitable for fNIRS and DOT equipped with 12 dual wavelength light sources and 13 SiPM detectors arranged in a square 8 cm \(\times\) 8 cm grid array. No optical fibers are used, since LEDs and SiPMs, opportunely encapsulated, are placed directly on the surface of the tissue to be analyzed, avoiding fiber-scal coupling or fiber lateral torqueing issues. We tested the instrument on a multilayered phantom made of a highly scattered polymeric medium, with mechanically movable parts. We performed multiple measurements on the phantom and propose a suitable calibration procedure to optimize the SNR. We discuss various critical aspects, such as SiPM signal drift, SiPM linearity, corrections to channel signal differences, and the SNR. Finally, we show an example of the imaging methodology. The results clearly demonstrate the high capabilities of SiPMs for the development of human brain cortex functional imaging systems.