Infrared Sensors for NDIR Type Gas Sensors Asahi Kasei Microdevices Infrared Sensors for NDIR-Type Gas Sensors utilize AKM's unique compound semiconductor technology. The technology delivers wavelength sensitivity control for the optimum gas absorption wavelength band, high-speed response, and high Signal-to-Noise Ratio (SNR). The infrared sensors feature high sensitivity, speed response, and reliability. Additionally, the sensors have a built-in optical bandpass filter.