Coherent® Thermopile Power Sensors are ideal solutions for measuring the average power of continuous wave lasers or pulsed laser energy. Thermopile sensors operate by absorbing and converting incident laser radiation into heat, which then flows to a heat sink. The temperature difference between the absorber and heat sink is converted into an electrical signal by a thermocouple junction. Unlike semiconductor sensors, thermopile sensors do not saturate. Unlike semiconductor sensors, thermopile sensors feature high power capability and flat spectral response.