An Infrared Radiation (IR) sensing device comprises a lens module, an IR pass filter, and an optical sensor. The lens module is utilized for focusing light. The IR pass filter comprises an optical coating, and a Color Filter Array (CFA) module. The optical coating is utilized for blocking light with wavelength around a predetermined range. The CFA module is utilized for blocking light with wavelength around 400 nm to 780 nm. The optical sensor for absorbing photons of light after being blocked by the IR pass filter on the optical path and accordingly generating an electrical signal. With the help of the CFAs, the range of the wavelength that the optical coating has to block becomes smaller, which greatly reduces the required number of layers of the optical coating.