Many applications require detectors with both high sensitivity and linearity, such as low light level imaging and quantum computing. Here we present an opto-electro-mechanical detector based on nano-injection and lateral charge compression that operates at the short infrared (SWIR) range. Electrical signal is generated by photo-induced changes in a nano-injector gap, and subsequent change of tunneling current. We present a theoretical model developed for the OEM detector, and it shows good agreement with the measured experimental results for both the mechanical and electrical properties of the device. The device shows a measured responsivity of 276 A/W, equivalent to 220 electrons per incoming photon, and an NEP of 3.53 x 10(-14) W/Hz(0.5) at room temperature. Although these results are already competing with common APDs in linear mode, we believe replacing the AFM tip with a dedicated nano-injector can improve the sensitivity significantly.